Financing - Schedule of Shares Used to Compute Diluted Earnings Per Share (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Disclosure [Abstract]
As reported shares (in shares)	1,061	1,058	1,060	1,058
Effect of stock-based compensation (in shares)	7	6	7	6
Diluted shares (in shares)	1,068	1,064	1,067	1,064