Income Taxes - Schedule of Current and Deferred Components of Income Tax Expense (Benefit) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income tax expense (benefit):
Federal income tax expense (benefit), Current	$ 108	$ 6	$ 157
Federal income tax expense (benefit), Deferred	47	85	(63)
State and city income tax expense (benefit), Current	18	15	22
State and city income tax expense (benefit), Deferred	22	9	17
Foreign income tax expense (benefit)	53	13	37
Income tax expense (benefit)	$ 248	$ 128	$ 170