Commitments and Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 05, 2016	Jul. 15, 2016	Dec. 31, 2013	Jul. 25, 2011
Loss Contingencies [Line Items]
Standard Product Warranty Accrual			$ 1,894	$ 1,574			$ 1,551
Product Warranty Accrual, Warranties Issued		$ 2,405	2,640	2,048
Product Warranty Expense		(2,511)	(2,320)	(2,025)
Product Warranty Accrual, Payments		1,788	1,894	1,574
Loss Contingency, Damages Awarded, Value	$ 14,600	14,512
Payments for Legal Settlements			0	10,613
Estimated Litigation Liability	3,252	3,252
Estimated Litigation Liability, Current	0	0	3,252		$ 1,289
Loss Contingency Damages Awarded Value 2		14,632
Operating Leases, Rent Expense		$ 3,296	3,525	3,716
Document Period End Date		Dec. 31, 2016
Operatingleases,equipment		$ 99	105	95
Operating Leases, Future Minimum Payments Due	2,922	2,922
Operating Leases, Future Minimum Payments, Due in Two Years	2,621	2,621
Operating Leases, Future Minimum Payments, Due in Three Years	1,780	1,780
Operating Leases, Future Minimum Payments, Due in Four Years	1,010	1,010
Operating Leases, Future Minimum Payments, Due in Five Years	541	541
Operating Leases, Future Minimum Payments, Due Thereafter	772	772
Royalty Expense		586	813	$ 819
Purchase Commitment, Remaining Minimum Amount Committed	19,296	19,296
Debt Instrument, Face Amount	$ 0	$ 0	$ 60,000			$ 60,000		$ 60,000