v3.19.3.a.u2
Additional Financial Information (Cash and Cash Equivalents and Restricted Cash) (Details) - USD ($)
$ in Millions
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]        
Cash and cash equivalents $ 12,130 $ 5,204 $ 50,498 $ 5,788
Restricted cash in Other current assets 69 61 6 7
Restricted cash in Other Assets 96 135 428 140
Cash and cash equivalents and restricted cash $ 12,295 $ 5,400 $ 50,932 $ 5,935