v3.19.3.a.u2
Pension And Postretirement Benefits (Schedule Of Fair Value Of Pension And Postretirement Assets And Liabilities By Level) (Details) - USD ($)
$ in Millions
Dec. 31, 2019
Dec. 31, 2018
Pension Assets And Liabilities Fair Value [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Non-interest bearing cash $ 85 $ 52
Interest bearing cash 529 208
Foreign currency contracts 5 5
Equity securities - Domestic equities 8,072 6,913
Equity securities - International equities 3,946 3,602
Prefered Interest 8,806 8,749
Fixed income securities - Corporate bonds and other instruments 10,473 10,723
Fixed income securities - Government and municipal bonds 6,172 6,221
Fixed income securities - Mortgage-backed securities 524 382
Real estate and real assets 2,817 2,579
Securities lending collateral 1,761 1,478
Purchased options, futures, and swaps   3
Receivable for variation margin 5 19
Assets at fair value 43,195 40,934
Investments sold short and other liabilities at fair value (515) (663)
Total plan net assets at fair value 42,680 40,271
Assets held at net asset value practical expedient    
Private equity funds 4,544 4,384
Real estate funds 2,062 2,162
Commingled funds 5,710 5,740
Total assets held at net asset value practical expedient 12,316 12,286
Other assets (liabilities) [1] (1,466) (876)
Total Plan Net Assets 53,530 51,681
Pension Assets And Liabilities Fair Value [Member] | Level 1 [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Non-interest bearing cash 85 52
Interest bearing cash 529 167
Foreign currency contracts 0 0
Equity securities - Domestic equities 8,068 6,912
Equity securities - International equities 3,929 3,594
Prefered Interest 0 0
Fixed income securities - Corporate bonds and other instruments 0 0
Fixed income securities - Government and municipal bonds 49 51
Fixed income securities - Mortgage-backed securities 0 0
Real estate and real assets 0 0
Securities lending collateral 103 12
Purchased options, futures, and swaps   0
Receivable for variation margin 5 19
Assets at fair value 12,768 10,807
Investments sold short and other liabilities at fair value (513) (657)
Total plan net assets at fair value 12,255 10,150
Pension Assets And Liabilities Fair Value [Member] | Level 2 [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Non-interest bearing cash 0 0
Interest bearing cash 0 41
Foreign currency contracts 5 5
Equity securities - Domestic equities 0 0
Equity securities - International equities 11 8
Prefered Interest 0 0
Fixed income securities - Corporate bonds and other instruments 10,469 10,719
Fixed income securities - Government and municipal bonds 6,123 6,170
Fixed income securities - Mortgage-backed securities 522 382
Real estate and real assets 0 0
Securities lending collateral 1,658 1,466
Purchased options, futures, and swaps   3
Receivable for variation margin 0 0
Assets at fair value 18,788 18,794
Investments sold short and other liabilities at fair value (2) (6)
Total plan net assets at fair value 18,786 18,788
Pension Assets And Liabilities Fair Value [Member] | Level 3 [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Non-interest bearing cash 0 0
Interest bearing cash 0 0
Foreign currency contracts 0 0
Equity securities - Domestic equities 4 1
Equity securities - International equities 6 0
Prefered Interest 8,806 8,749
Fixed income securities - Corporate bonds and other instruments 4 4
Fixed income securities - Government and municipal bonds 0 0
Fixed income securities - Mortgage-backed securities 2 0
Real estate and real assets 2,817 2,579
Securities lending collateral 0 0
Purchased options, futures, and swaps   0
Receivable for variation margin 0 0
Assets at fair value 11,639 11,333
Investments sold short and other liabilities at fair value 0 0
Total plan net assets at fair value 11,639 11,333
Postretirement Assets And Liabilities Fair Value [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Interest bearing cash 549 669
Equity securities - Domestic equities 438 753
Equity securities - International equities 265 542
Fixed income securities - Corporate bonds and other instruments 530 620
Fixed income securities - Government and municipal bonds 189 380
Fixed income securities - Mortgage-backed securities 294 283
Securities lending collateral 36 63
Assets at fair value 2,301 3,310
Securities lending payable and other liabilities (36) (74)
Total plan net assets at fair value 2,265 3,236
Assets held at net asset value practical expedient    
Private equity funds 66 79
Real estate funds 27 36
Commingled funds 1,797 973
Total assets held at net asset value practical expedient 1,890 1,088
Other assets (liabilities) (10) [1] (47) [2]
Total Plan Net Assets 4,145 4,277
Postretirement Assets And Liabilities Fair Value [Member] | Level 1 [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Interest bearing cash 248 45
Equity securities - Domestic equities 438 745
Equity securities - International equities 265 541
Fixed income securities - Corporate bonds and other instruments 7 7
Fixed income securities - Government and municipal bonds 6 2
Fixed income securities - Mortgage-backed securities 0 0
Securities lending collateral 0 0
Assets at fair value 964 1,340
Securities lending payable and other liabilities 0 0
Total plan net assets at fair value 964 1,340
Postretirement Assets And Liabilities Fair Value [Member] | Level 2 [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Interest bearing cash 301 624
Equity securities - Domestic equities 0 8
Equity securities - International equities 0 0
Fixed income securities - Corporate bonds and other instruments 492 602
Fixed income securities - Government and municipal bonds 182 377
Fixed income securities - Mortgage-backed securities 294 283
Securities lending collateral 36 63
Assets at fair value 1,305 1,957
Securities lending payable and other liabilities (36) (74)
Total plan net assets at fair value 1,269 1,883
Postretirement Assets And Liabilities Fair Value [Member] | Level 3 [Member]    
Defined Benefit Plan Disclosure [Line Items]    
Interest bearing cash 0 0
Equity securities - Domestic equities 0 0
Equity securities - International equities 0 1
Fixed income securities - Corporate bonds and other instruments 31 11
Fixed income securities - Government and municipal bonds 1 1
Fixed income securities - Mortgage-backed securities 0 0
Securities lending collateral 0 0
Assets at fair value 32 13
Securities lending payable and other liabilities 0 0
Total plan net assets at fair value $ 32 $ 13
[1] Other assets (liabilities) include amounts receivable, accounts payable and net adjustment for securities lending payable.
[2] Other assets (liabilities) include amounts receivable and accounts payable.