v3.19.3.a.u2
Pension and Postretirement Benefit Plans - Pension Asset Fair Values (Details) - Funded - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Qualified and Non-qualified Pension Benefits | United States      
Benefit Plan Information      
Total, before other items to reconcile $ 16,557 $ 15,062  
Other items to reconcile to fair value of plan assets (458) (259)  
Fair value of plan assets 16,099 14,803 $ 15,686
Qualified and Non-qualified Pension Benefits | International      
Benefit Plan Information      
Total, before other items to reconcile 6,976 6,223  
Other items to reconcile to fair value of plan assets (53) (53)  
Fair value of plan assets 6,923 6,170 6,737
Qualified and Non-qualified Pension Benefits | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 5,612 4,988  
Qualified and Non-qualified Pension Benefits | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 1,873 1,578  
Qualified and Non-qualified Pension Benefits | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 5,584 4,464  
Qualified and Non-qualified Pension Benefits | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 3,778 2,828  
Qualified and Non-qualified Pension Benefits | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 540 527  
Qualified and Non-qualified Pension Benefits | Global equity | United States      
Benefit Plan Information      
Total, before other items to reconcile 3,577 2,975  
Qualified and Non-qualified Pension Benefits | Global equity | International      
Benefit Plan Information      
Total, before other items to reconcile 2,312 2,014  
Qualified and Non-qualified Pension Benefits | Global equity | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 3,160 2,603  
Qualified and Non-qualified Pension Benefits | Global equity | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 1,395 961  
Qualified and Non-qualified Pension Benefits | Global equity | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 894 1,032  
Qualified and Non-qualified Pension Benefits | Global equity | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 5 5  
Qualified and Non-qualified Pension Benefits | U.S. equities | United States      
Benefit Plan Information      
Total, before other items to reconcile 1,575 1,369  
Qualified and Non-qualified Pension Benefits | U.S. equities | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 1,575 1,369  
Qualified and Non-qualified Pension Benefits | Non-U.S. equities | United States      
Benefit Plan Information      
Total, before other items to reconcile 1,585 1,234  
Qualified and Non-qualified Pension Benefits | Non-U.S. equities | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 1,585 1,234  
Qualified and Non-qualified Pension Benefits | Growth equities | International      
Benefit Plan Information      
Total, before other items to reconcile 1,434 708  
Qualified and Non-qualified Pension Benefits | Growth equities | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 638 460  
Qualified and Non-qualified Pension Benefits | Growth equities | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 796 248  
Qualified and Non-qualified Pension Benefits | Value equities | International      
Benefit Plan Information      
Total, before other items to reconcile 706 488  
Qualified and Non-qualified Pension Benefits | Value equities | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 696 446  
Qualified and Non-qualified Pension Benefits | Value equities | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 10 42  
Qualified and Non-qualified Pension Benefits | Core equities | International      
Benefit Plan Information      
Total, before other items to reconcile 154 802  
Qualified and Non-qualified Pension Benefits | Core equities | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 61 55  
Qualified and Non-qualified Pension Benefits | Core equities | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 88 742  
Qualified and Non-qualified Pension Benefits | Core equities | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 5 5  
Qualified and Non-qualified Pension Benefits | Equities valued at net asset value | International      
Benefit Plan Information      
Total, before other items to reconcile 18 16  
Qualified and Non-qualified Pension Benefits | Index and long/short equity | United States      
Benefit Plan Information      
Total, before other items to reconcile 417 372  
Qualified and Non-qualified Pension Benefits | Fixed income | United States      
Benefit Plan Information      
Total, before other items to reconcile 7,814 6,256  
Qualified and Non-qualified Pension Benefits | Fixed income | International      
Benefit Plan Information      
Total, before other items to reconcile 3,475 3,180  
Qualified and Non-qualified Pension Benefits | Fixed income | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 2,351 1,900  
Qualified and Non-qualified Pension Benefits | Fixed income | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 378 540  
Qualified and Non-qualified Pension Benefits | Fixed income | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 5,463 4,347  
Qualified and Non-qualified Pension Benefits | Fixed income | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 2,635 1,665  
Qualified and Non-qualified Pension Benefits | Fixed income | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 13 14  
Qualified and Non-qualified Pension Benefits | U.S. government securities | United States      
Benefit Plan Information      
Total, before other items to reconcile 3,262 2,621  
Qualified and Non-qualified Pension Benefits | U.S. government securities | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 2,346 1,889  
Qualified and Non-qualified Pension Benefits | U.S. government securities | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 916 732  
Qualified and Non-qualified Pension Benefits | Domestic government debt | International      
Benefit Plan Information      
Total, before other items to reconcile 790 690  
Qualified and Non-qualified Pension Benefits | Domestic government debt | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 353 334  
Qualified and Non-qualified Pension Benefits | Domestic government debt | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 433 351  
Qualified and Non-qualified Pension Benefits | Domestic government debt | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 4 5  
Qualified and Non-qualified Pension Benefits | Foreign government agency securities | United States      
Benefit Plan Information      
Total, before other items to reconcile 61 44  
Qualified and Non-qualified Pension Benefits | Foreign government agency securities | International      
Benefit Plan Information      
Total, before other items to reconcile 625 471  
Qualified and Non-qualified Pension Benefits | Foreign government agency securities | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 22 150  
Qualified and Non-qualified Pension Benefits | Foreign government agency securities | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 61 44  
Qualified and Non-qualified Pension Benefits | Foreign government agency securities | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 603 321  
Qualified and Non-qualified Pension Benefits | Preferred and convertible securities | United States      
Benefit Plan Information      
Total, before other items to reconcile 52 44  
Qualified and Non-qualified Pension Benefits | Preferred and convertible securities | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 52 44  
Qualified and Non-qualified Pension Benefits | U.S. corporate bonds | United States      
Benefit Plan Information      
Total, before other items to reconcile 3,576 2,950  
Qualified and Non-qualified Pension Benefits | U.S. corporate bonds | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 10 9  
Qualified and Non-qualified Pension Benefits | U.S. corporate bonds | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 3,566 2,941  
Qualified and Non-qualified Pension Benefits | Non-U.S. corporate bonds | United States      
Benefit Plan Information      
Total, before other items to reconcile 759 475  
Qualified and Non-qualified Pension Benefits | Non-U.S. corporate bonds | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 759 475  
Qualified and Non-qualified Pension Benefits | Corporate debt securities | International      
Benefit Plan Information      
Total, before other items to reconcile 1,611 1,058  
Qualified and Non-qualified Pension Benefits | Corporate debt securities | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 3 56  
Qualified and Non-qualified Pension Benefits | Corporate debt securities | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 1,599 993  
Qualified and Non-qualified Pension Benefits | Corporate debt securities | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 9 9  
Qualified and Non-qualified Pension Benefits | Other | United States      
Benefit Plan Information      
Total, before other items to reconcile   9  
Qualified and Non-qualified Pension Benefits | Derivative instruments | United States      
Benefit Plan Information      
Total, before other items to reconcile 104 113  
Qualified and Non-qualified Pension Benefits | Derivative instruments | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile (5) 2  
Qualified and Non-qualified Pension Benefits | Derivative instruments | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 109 111  
Qualified and Non-qualified Pension Benefits | Fixed income securities valued at net asset value | International      
Benefit Plan Information      
Total, before other items to reconcile 449 961  
Qualified and Non-qualified Pension Benefits | Private equity | United States      
Benefit Plan Information      
Total, before other items to reconcile 1,945 2,109  
Qualified and Non-qualified Pension Benefits | Private equity | International      
Benefit Plan Information      
Total, before other items to reconcile 338 210  
Qualified and Non-qualified Pension Benefits | Private equity | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 80 45  
Qualified and Non-qualified Pension Benefits | Private equity | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 6 5  
Qualified and Non-qualified Pension Benefits | Private equity | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 207 75  
Qualified and Non-qualified Pension Benefits | Private equity | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 4 4  
Qualified and Non-qualified Pension Benefits | Growth equity | United States      
Benefit Plan Information      
Total, before other items to reconcile 80 45  
Qualified and Non-qualified Pension Benefits | Growth equity | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 80 45  
Qualified and Non-qualified Pension Benefits | Real estate | International      
Benefit Plan Information      
Total, before other items to reconcile 217 84  
Qualified and Non-qualified Pension Benefits | Real estate | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 6 5  
Qualified and Non-qualified Pension Benefits | Real estate | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 207 75  
Qualified and Non-qualified Pension Benefits | Real estate | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 4 4  
Qualified and Non-qualified Pension Benefits | Real estate valued at net asset value | International      
Benefit Plan Information      
Total, before other items to reconcile 36 37  
Qualified and Non-qualified Pension Benefits | Partnership investments | United States      
Benefit Plan Information      
Total, before other items to reconcile 1,865 2,064  
Qualified and Non-qualified Pension Benefits | Partnership investments | International      
Benefit Plan Information      
Total, before other items to reconcile 85 89  
Qualified and Non-qualified Pension Benefits | Absolute return | United States      
Benefit Plan Information      
Total, before other items to reconcile 2,717 2,437  
Qualified and Non-qualified Pension Benefits | Absolute return | International      
Benefit Plan Information      
Total, before other items to reconcile 717 725  
Qualified and Non-qualified Pension Benefits | Absolute return | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 1 28  
Qualified and Non-qualified Pension Benefits | Absolute return | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile   1  
Qualified and Non-qualified Pension Benefits | Absolute return | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 117 114  
Qualified and Non-qualified Pension Benefits | Absolute return | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 3 34  
Qualified and Non-qualified Pension Benefits | Absolute return | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 518 504  
Qualified and Non-qualified Pension Benefits | Insurance | International      
Benefit Plan Information      
Total, before other items to reconcile 513 496  
Qualified and Non-qualified Pension Benefits | Insurance | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 513 496  
Qualified and Non-qualified Pension Benefits | Hedge fund/fund of funds | United States      
Benefit Plan Information      
Total, before other items to reconcile 2,010 1,866  
Qualified and Non-qualified Pension Benefits | Fixed income and other | United States      
Benefit Plan Information      
Total, before other items to reconcile 118 142  
Qualified and Non-qualified Pension Benefits | Fixed income and other | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 1 28  
Qualified and Non-qualified Pension Benefits | Fixed income and other | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 117 114  
Qualified and Non-qualified Pension Benefits | Partnership investments - absolute return | United States      
Benefit Plan Information      
Total, before other items to reconcile 589 429  
Qualified and Non-qualified Pension Benefits | Derivatives - absolute return | International      
Benefit Plan Information      
Total, before other items to reconcile 3 2  
Qualified and Non-qualified Pension Benefits | Derivatives - absolute return | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile   1  
Qualified and Non-qualified Pension Benefits | Derivatives - absolute return | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 3 1  
Qualified and Non-qualified Pension Benefits | Other | International      
Benefit Plan Information      
Total, before other items to reconcile 5 41  
Qualified and Non-qualified Pension Benefits | Other | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile   33  
Qualified and Non-qualified Pension Benefits | Other | Level 3 | International      
Benefit Plan Information      
Total, before other items to reconcile 5 8  
Qualified and Non-qualified Pension Benefits | Other valued at net asset value | International      
Benefit Plan Information      
Total, before other items to reconcile 1    
Qualified and Non-qualified Pension Benefits | Hedge funds | International      
Benefit Plan Information      
Total, before other items to reconcile 195 186  
Qualified and Non-qualified Pension Benefits | Cash and Cash Equivalent | United States      
Benefit Plan Information      
Total, before other items to reconcile 504 1,285  
Qualified and Non-qualified Pension Benefits | Cash and Cash Equivalent | International      
Benefit Plan Information      
Total, before other items to reconcile 134 94  
Qualified and Non-qualified Pension Benefits | Cash and Cash Equivalent | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 20 412  
Qualified and Non-qualified Pension Benefits | Cash and Cash Equivalent | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 94 71  
Qualified and Non-qualified Pension Benefits | Cash and Cash Equivalent | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 4 3  
Qualified and Non-qualified Pension Benefits | Cash and Cash Equivalent | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 39 22  
Qualified and Non-qualified Pension Benefits | Cash and cash equivalents | United States      
Benefit Plan Information      
Total, before other items to reconcile 25 416  
Qualified and Non-qualified Pension Benefits | Cash and cash equivalents | International      
Benefit Plan Information      
Total, before other items to reconcile 133 93  
Qualified and Non-qualified Pension Benefits | Cash and cash equivalents | Level 1 | United States      
Benefit Plan Information      
Total, before other items to reconcile 20 412  
Qualified and Non-qualified Pension Benefits | Cash and cash equivalents | Level 1 | International      
Benefit Plan Information      
Total, before other items to reconcile 94 71  
Qualified and Non-qualified Pension Benefits | Cash and cash equivalents | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile 5 4  
Qualified and Non-qualified Pension Benefits | Cash and cash equivalents | Level 2 | International      
Benefit Plan Information      
Total, before other items to reconcile 39 22  
Qualified and Non-qualified Pension Benefits | Repurchase Agreements And Derivative Margin Activity | United States      
Benefit Plan Information      
Total, before other items to reconcile (1) (1)  
Qualified and Non-qualified Pension Benefits | Repurchase Agreements And Derivative Margin Activity | Level 2 | United States      
Benefit Plan Information      
Total, before other items to reconcile (1) (1)  
Qualified and Non-qualified Pension Benefits | Cash and cash equivalents valued at net asset value | United States      
Benefit Plan Information      
Total, before other items to reconcile 480 870  
Qualified and Non-qualified Pension Benefits | Cash and cash equivalents valued at net asset value | International      
Benefit Plan Information      
Total, before other items to reconcile 1 1  
Postretirement Benefits      
Benefit Plan Information      
Total, before other items to reconcile 1,361 1,272  
Other items to reconcile to fair value of plan assets (23) (12)  
Fair value of plan assets $ 1,338 1,260 $ 1,397
Percentage of plan assets within 401h account 50.00%    
Postretirement Benefits | Level 1      
Benefit Plan Information      
Total, before other items to reconcile $ 587 576  
Postretirement Benefits | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 508 426  
Postretirement Benefits | Global equity      
Benefit Plan Information      
Total, before other items to reconcile 447 448  
Postretirement Benefits | Global equity | Level 1      
Benefit Plan Information      
Total, before other items to reconcile 414 414  
Postretirement Benefits | U.S. equities      
Benefit Plan Information      
Total, before other items to reconcile 337 356  
Postretirement Benefits | U.S. equities | Level 1      
Benefit Plan Information      
Total, before other items to reconcile 337 356  
Postretirement Benefits | Non-U.S. equities      
Benefit Plan Information      
Total, before other items to reconcile 77 58  
Postretirement Benefits | Non-U.S. equities | Level 1      
Benefit Plan Information      
Total, before other items to reconcile 77 58  
Postretirement Benefits | Index and long/short equity      
Benefit Plan Information      
Total, before other items to reconcile 33 34  
Postretirement Benefits | Fixed income      
Benefit Plan Information      
Total, before other items to reconcile 638 528  
Postretirement Benefits | Fixed income | Level 1      
Benefit Plan Information      
Total, before other items to reconcile 136 112  
Postretirement Benefits | Fixed income | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 502 416  
Postretirement Benefits | U.S. government securities      
Benefit Plan Information      
Total, before other items to reconcile 378 325  
Postretirement Benefits | U.S. government securities | Level 1      
Benefit Plan Information      
Total, before other items to reconcile 136 112  
Postretirement Benefits | U.S. government securities | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 242 213  
Postretirement Benefits | Foreign government agency securities      
Benefit Plan Information      
Total, before other items to reconcile 6 4  
Postretirement Benefits | Foreign government agency securities | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 6 4  
Postretirement Benefits | U.S. corporate bonds      
Benefit Plan Information      
Total, before other items to reconcile 203 162  
Postretirement Benefits | U.S. corporate bonds | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 203 162  
Postretirement Benefits | Non-U.S. corporate bonds      
Benefit Plan Information      
Total, before other items to reconcile 46 32  
Postretirement Benefits | Non-U.S. corporate bonds | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 46 32  
Postretirement Benefits | Derivative instruments      
Benefit Plan Information      
Total, before other items to reconcile 5 5  
Postretirement Benefits | Derivative instruments | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 5 5  
Postretirement Benefits | Private equity      
Benefit Plan Information      
Total, before other items to reconcile 96 103  
Postretirement Benefits | Private equity | Level 1      
Benefit Plan Information      
Total, before other items to reconcile 4 2  
Postretirement Benefits | Growth equity      
Benefit Plan Information      
Total, before other items to reconcile 4 2  
Postretirement Benefits | Growth equity | Level 1      
Benefit Plan Information      
Total, before other items to reconcile 4 2  
Postretirement Benefits | Partnership investments      
Benefit Plan Information      
Total, before other items to reconcile 92 101  
Postretirement Benefits | Absolute return      
Benefit Plan Information      
Total, before other items to reconcile 124 104  
Postretirement Benefits | Absolute return | Level 1      
Benefit Plan Information      
Total, before other items to reconcile   1  
Postretirement Benefits | Absolute return | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 5 5  
Postretirement Benefits | Hedge fund/fund of funds      
Benefit Plan Information      
Total, before other items to reconcile 92 80  
Postretirement Benefits | Fixed income and other      
Benefit Plan Information      
Total, before other items to reconcile 5 6  
Postretirement Benefits | Fixed income and other | Level 1      
Benefit Plan Information      
Total, before other items to reconcile   1  
Postretirement Benefits | Fixed income and other | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 5 5  
Postretirement Benefits | Partnership investments - absolute return      
Benefit Plan Information      
Total, before other items to reconcile 27 18  
Postretirement Benefits | Cash and Cash Equivalent      
Benefit Plan Information      
Total, before other items to reconcile 56 89  
Postretirement Benefits | Cash and Cash Equivalent | Level 1      
Benefit Plan Information      
Total, before other items to reconcile 33 47  
Postretirement Benefits | Cash and Cash Equivalent | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 1 5  
Postretirement Benefits | Cash and cash equivalents      
Benefit Plan Information      
Total, before other items to reconcile 34 52  
Postretirement Benefits | Cash and cash equivalents | Level 1      
Benefit Plan Information      
Total, before other items to reconcile 33 47  
Postretirement Benefits | Cash and cash equivalents | Level 2      
Benefit Plan Information      
Total, before other items to reconcile 1 5  
Postretirement Benefits | Cash and cash equivalents valued at net asset value      
Benefit Plan Information      
Total, before other items to reconcile $ 22 $ 37