Accounts Receivable, Sales and Allowances - Adjustments to Gross Sales (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Receivables [Abstract]
Gross sales	$ 379,022	$ 436,700	$ 1,303,671	$ 1,465,052
Less adjustments for:
Chargebacks	(141,943)	(188,884)	(540,055)	(635,329)
Rebates, administrative and other fees	(46,212)	(66,843)	(188,445)	(234,217)
Product returns	(5,900)	(4,805)	(23,273)	(18,059)
Discounts and allowances	(7,297)	(8,471)	(25,371)	(28,654)
Advertising, promotions and others	(1,426)	(2,072)	(6,355)	(8,161)
Revenues, net	$ 176,244	$ 165,625	$ 520,172	$ 540,632