Income Taxes - Deferred income taxes (assets and liabilities netted by jurisdiction) as classified in the Consolidated Statements of Financial Position (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Deferred tax assets — non-current	$ 724	$ 645
Deferred tax liabilities — non-current	(262)	(199)
Net deferred tax asset	$ 462	$ 446