Commitments and Contingencies - (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Dec. 31, 2015
Commitments and Contingencies [Abstract]
Standard Product Warranty Accrual	$ 2,136	$ 1,836	$ 1,788	$ 1,894
Product Warranty Accrual, Warranties Issued	1,659	1,261
Product Warranty Accrual, Payments	(1,311)	$ (1,319)
Loss Contingency, damages Awarded, Value 2	14,600
Proceeds from Legal Settlements	13,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 86,000
Line of Credit Facility, Interest Rate at Period End	2.80%