Accounts Receivable Allowances (Details) - Net Trade Accounts Receivable - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Receivables [Abstract]
Gross accounts receivable	$ 512,417	$ 466,570
Less reserves for:
Chargebacks	(80,880)	(91,844)
Rebates	(153,768)	(162,596)
Product returns	(60,043)	(48,333)
Discounts and allowances	(9,835)	(10,079)
Advertising and promotions	(1,403)	(1,518)
Doubtful accounts	(1,483)	(1,579)
Trade accounts receivable, net	$ 205,005	$ 150,621