Schedule II - Valuation and Qualifying Accounts and Reserves (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Valuation Allowance for Deferred Tax Assets [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of the period	$ 71,515	$ 109,030	$ 84,960
Charged to income	3,943	(37,515)	24,070
Balance at end of the period	75,458	71,515	109,030
Allowance for Rebates [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of the period	5,648	3,842	4,470
Charged to income	37,071	17,236	(1,204)
Charged to other accounts	813	(132)	11,501
Deductions	(31,270)	(15,298)	(10,925)
Balance at end of the period	12,261	5,648	3,842
Allowance for Price Adjustments and Chargebacks [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of the period	3,925	602	383
Charged to income	13,033	6,738	36
Charged to other accounts		(3)	1,711
Deductions	(12,940)	(3,412)	(1,528)
Balance at end of the period	4,018	3,925	$ 602
Allowance for inventory obsolescence [Member]
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of the period	243
Charged to income	(56)	243
Balance at end of the period	$ 187	$ 243