Commitments and Contingencies - Adverse Purchase Commitments and Accrued Warranty (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Class of Warrant or Right [Line Items]
Purchase Commitment, Remaining Minimum Amount Committed	$ 2,200	$ 1,700
Semi-annual Performance Period, Maximum Multiplier of Original Grant	2.75
Movement in Standard Product Warranty Accrual [Roll Forward]
Warranty liability balance, beginning of the year	$ 2,600	3,328
Product warranty accruals	2,025	2,665
Adjustments for payments made	(2,072)	(3,393)
Warranty liability balance, end of the year	2,553	2,600
Accrued warranty reserve	2,036	2,018
Accrued warranty reserve	$ 517	$ 582
Minimum [Member]
Class of Warrant or Right [Line Items]
Warranty, Term	12 months
Maximum [Member]
Class of Warrant or Right [Line Items]
Warranty, Term	24 months