Commitments and Contingencies - (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies [Abstract]
Standard Product Warranty Accrual	$ 1,995	$ 1,773	$ 1,788	$ 1,894
Product Warranty Accrual, Warranties Issued	855	544
Product Warranty Accrual, Payments	(648)	$ (665)
Loss Contingency, damages Awarded, Value 2	14,600
Line of Credit Facility, Remaining Borrowing Capacity	$ 72,000
Line of Credit Facility, Interest Rate at Period End	2.50%