Financing - Schedule of Shares Used to Compute Diluted Earnings Per Share (Details) - shares shares in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Disclosure [Abstract]
As reported shares (in shares)	1,061	1,058	1,060	1,057
Effect of stock-based compensation (in shares)	6	5	6	7
Effect of equity units (in shares)	0	0	0	1
Diluted shares (in shares)	1,067	1,063	1,066	1,065