Income Taxes - Difference Between the Effective Tax Rate and the U.S. Federal Statutory Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax expense at the U.S. federal tax rate	21.00%	21.00%	35.00%
Foreign income tax differential	(49.20%)	2.10%	(22.60%)
U.S. tax on foreign earnings	(8.40%)	2.00%	4.30%
State and local income taxes	58.20%	(25.00%)	(11.00%)
U.S. permanent book/tax differences	(17.00%)	(2.70%)	(1.50%)
U.S. research and development tax credits	68.50%	(29.50%)	(11.20%)
Change in valuation allowance	(49.10%)	27.70%	10.00%
U.S. manufacturing deduction permanent difference	0.00%	0.00%	(8.00%)
Tax impact of equity compensation	(49.30%)	(1.40%)	0.70%
Deferred tax impact from U.S. rate change from Tax Reform	0.00%	0.00%	(27.00%)
Tax impact of U.S. Tax Reform/Transition Tax	0	(0.239)	2.500
Tax Impact of uncertain tax positions	(24.60%)	20.20%	(3.60%)
Other, net	(3.90%)	(1.60%)	0.40%
Effective income tax rate	(53.80%)	(11.10%)	215.50%