Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Line Items]
Deferred income taxes		$ 103	$ (14)	$ 192
Foreign net operating loss carryforwards		981
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities		4	3	0
Deferred Tax Liabilities, Undistributed Foreign Earnings		811
Internal Revenue Service (IRS)
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards net of valuation allowances		$ 6,000
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	$ (30)			$ (104)