Income Taxes - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Effective tax rates before discrete tax items	26.00%	15.00%
Income tax expense before discrete tax items	$ 44	$ 13
Income tax expense	$ 60	$ 25
Liabilities for unrecognized tax benefits			$ 128