Capital Stock - Narrative (Details) - USD ($)			1 Months Ended	12 Months Ended			96 Months Ended
	Dec. 02, 2020	Jan. 31, 2018	Jan. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2018
Class of Stock [Line Items]
Common stock, shares authorized (in shares)				5,000,000,000	5,000,000,000		5,000,000,000
Preferred stock, shares authorized (in shares)				500,000,000
Preferred stock, shares issued (in shares)				0	0	0	0
Preferred stock, shares outstanding (in shares)				0	0	0	0
Amount of shares repurchased				$ 2,096,000,000	$ 1,401,000,000	$ 1,499,000,000
Common Stock
Class of Stock [Line Items]
Common stock, shares authorized (in shares)				5,000,000,000
Common stock reserved for stock option and other stock awards (in shares)				77,100,000
Stock repurchase value								$ 13,700,000,000
Amount of shares repurchased				$ 2,100,000,000
Number of shares repurchased (in shares)				35,384,366	25,071,845	30,902,465
Average cost of shares repurchased (in dollars per share)				$ 59.24
Stock repurchase remaining amount				$ 3,700,000,000
Common Stock | Subsequent Event
Class of Stock [Line Items]
Amount of shares repurchased			$ 16,000,000
Common Stock | Share Repurchase Program amended January 1, 2018
Class of Stock [Line Items]
Stock repurchase value		$ 19,700,000,000
Increase in share repurchase value		$ 6,000,000,000
Stock repurchase expiration date		Dec. 31, 2020
Common Stock | Share Repurchase Program amended December 2, 2020
Class of Stock [Line Items]
Stock repurchase value	$ 23,700,000,000
Increase in share repurchase value	$ 4,000,000,000
Stock repurchase expiration date	Dec. 31, 2023
Common Stock | Prior to January 1, 2020
Class of Stock [Line Items]
Amount of shares repurchased							$ 18,000,000,000