Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Line Items]
Deferred income taxes	$ 317	$ 103	$ (14)
Foreign net operating loss carryforwards	1,200
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	3	4	3
Deferred Tax Liabilities, Undistributed Foreign Earnings	900
Internal Revenue Service (IRS)
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards net of valuation allowances	$ 3,500
Provision adjustment due to corporate tax rate change [Member]
Income Tax Disclosure [Line Items]
Deferred income taxes		$ (30)	(317)
Provision adjustment due to anticipated repatriation of foreign earnings [Member]
Income Tax Disclosure [Line Items]
Deferred income taxes			$ (104)