Accrued Liabilities Accrued rebates, chargebacks and other reserves (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Contract assets [Line Items]
Government rebates and chargebacks	$ 8,901	$ 8,709
Assistance and Other Discounts	3,457	4,178
Product return	4,681	3,304
Discount and Distribution Fees	3,094	3,422
Accrued liabilities, amounts received in advance of revenue recognition	20,133	$ 19,613
Allowances for prior period sales	99
Payments for current period sales	(21,321)
Allowances for current period sales	38,559
Payments for prior period sales	(16,817)
Discount and Distribution Fees [Member]
Contract assets [Line Items]
Allowances for prior period sales	0
Payments for current period sales	(6,313)
Allowances for current period sales	9,403
Payments for prior period sales	(3,418)
Government Rebates and Chargebacks [Member]
Contract assets [Line Items]
Allowances for prior period sales	38
Payments for current period sales	(10,045)
Allowances for current period sales	18,583
Payments for prior period sales	(8,384)
Assistance and Other Discounts [Member]
Contract assets [Line Items]
Allowances for prior period sales	0
Payments for current period sales	(4,963)
Allowances for current period sales	8,206
Payments for prior period sales	(3,964)
Product Returns [Member]
Contract assets [Line Items]
Allowances for prior period sales	61
Payments for current period sales	0
Allowances for current period sales	2,367
Payments for prior period sales	$ (1,051)