Common Stock (Details) - USD ($)	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Nov. 30, 2019
Equity, Class of Treasury Stock [Line Items]
Common stock repurchased (in shares)		0
Purchase of treasury shares	$ 734,000,000
Stock-based compensation, shares issued during period (in shares)	3,100,000	3,400,000
Common Stock
Equity, Class of Treasury Stock [Line Items]
Share repurchases program, authorized amount (up to)			$ 2,500,000,000
Common stock repurchased (in shares)	5,300,000
Stock repurchase program, remaining authorized repurchase amount	$ 1,700,000,000