Income Taxes - Reconciliation of Provision for Income Taxes at US Federal Statutory Rate to Provision in Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Benefit at U.S. federal statutory rate		$ (33,240)	$ (87,592)	$ (175,436)
U.S. valuation allowance		19,141	64,907	558,976
Foreign earnings taxed at different rates, including foreign losses without benefit		51,612	103,231	266,807
U.S. Tax Act	$ 3,700	0	3,709	(107,049)
State and local taxes, net of U.S. federal (expense) benefit		2,438	(2,028)	2,254
Adjustments to previously accrued taxes		(14,160)	(6,621)	(5,159)
Change in indefinite reinvestment assertion		(2,700)	14,566	0
Other		3,813	12,782	2,623
Provision for income taxes		$ 55,224	116,196	$ 553,334
Tax credit expirations			$ 8,100