New Accounting Standards (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment	$ 10,686	$ 10,561	$ 12,153	$ 12,128
Cumulative-effect adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment			(12)	(31)
Retained Earnings
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment	$ 7,271	$ 6,466	7,993	7,706
Retained Earnings | Cumulative-effect adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment			$ (12)	$ (31)