Schedule II Valuation and Qualifying Accounts (Parenthetical) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2021	Jan. 01, 2020
Valuation And Qualifying Accounts Disclosure [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]				true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020			Jan. 31, 2021
Accounting Standards Update [Extensible List]	Accounting Standards Update 2016-13	us-gaap:AccountingStandardsUpdate201602Member	us-gaap:AccountingStandardsUpdate201409Member
Retained earnings	$ 4,809			$ 5,573
Accounts receivable	1,691			2,387
Deferred income taxes	$ 1,467			$ 1,596
Accounting Standards Update 2016-13 | Restatement Adjustment
Valuation And Qualifying Accounts Disclosure [Line Items]
Retained earnings					$ (12)
Accounts receivable					(15)
Deferred income taxes					$ 3