Accounts Receivable, Sales and Allowances - Net Trade Accounts Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Receivables [Abstract]
Gross accounts receivable	$ 405,379	$ 519,175
Less reserves for:
Chargebacks	(65,522)	(80,360)
Rebates	(94,743)	(97,935)
Product returns	(45,666)	(43,689)
Discounts and allowances	(9,045)	(12,389)
Advertising and promotions	(954)	(688)
Doubtful accounts	(610)	(960)
Trade accounts receivable, net	$ 188,839	$ 283,154