v3.10.0.1
Deferred Compensation Plans (Deferred Cash-based Compensation Plans) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Deferred Compensation Arrangements [Abstract]      
Deferred cash-based awards $ 1,174 $ 1,039 $ 950
Return on referenced investments 108 696 228
Total 1,282 1,735 1,178
Retirement eligible awards 193 $ 176 $ 151
Unrecognized Compensation Cost Related to Unvested Deferred Cash-Based Awards      
To be recognized in 2019 423    
To be recognized in 2020 151    
To be recognized thereafter 227    
Total $ 801