Accrued Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018		Mar. 31, 2018	Dec. 31, 2018
Accrued Liabilities [Abstract]
Salaries and benefits	$ 29,259	$ 20,538			$ 20,538
Incentive compensation	10,656	42,913			42,913
Operating Lease, Liability, Current	7,966	0			0
Accrued Product Field Action	4,259	5,316			5,316
Third-party Inventory	30				1,089
Consigned inventory	1,118	1,118			1,118
Sales taxes	2,567	2,941			2,941
Restructuring accrual	1,132	1,046			1,046
Contract with Customer, Liability, Current	6,079	3,814			3,814
Accrued other taxes	414	3,213			3,213
Accrued Professional Fees	12,712	15,996			15,996
Legal accrual	1,261	1,400			1,400
Distribution Fees	4,040	3,977			3,977
Warranties and returns	904	1,124			1,124
Accrued freight	10,795	10,953			10,953
contract settlement-ST	1,667	(12,700)		$ (28,900)	2,083
Accrued research and development expense	0				1,451
Other	10,006	9,848			9,848
Accrued liabilities	$ 104,865	$ 128,820	[1]		$ 128,820	[1]

[1] December 31, 2018 balances were derived from audited consolidated financial statements.