Commitments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 1996
Property Subject to or Available for Operating Lease [Line Items]
Term of lease		15 years
Capital leased property	$ 30,829	$ 30,849
Proceeds from assignment of purchase option under lease	0	1,669	$ 0
Increase in capital leased property		5,700
Capital lease obligations		22,000
Increase in capital lease obligations		6,700
Net book value of capital asset		18,300
Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments, Fiscal Year Maturity [Abstract]
2015	1,854
2016	1,900
2017	1,947
2018	1,995
2019	2,045
Remainder	19,364
Total minimum obligations	29,105
Less amounts representing interest (ranging from 5.8% to 18.8%)	(8,370)
Net present value of minimum obligations	20,735
Less current portion	(827)	(772)
Long-term capital lease obligations at December 31, 2013	19,908	20,735
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2015	531
2016	319
2017	298
2018	292
2019	300
Remainder	982
Total minimum lease payments	2,722
Rent expense charged to operations	1,800	1,100	1,100
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]
Balance Beginning of Year	189	113	226
Accruals	125	140	70
Warranty Expenses	(181)	(64)	(183)
Balance End of Year	$ 133	189	$ 113
Capital Lease Obligations [Member]
Property Subject to or Available for Operating Lease [Line Items]
Proceeds from assignment of purchase option under lease		1,700
Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments, Fiscal Year Maturity [Abstract]
Interest rate percentage, minimum	5.00%
Interest rate percentage, maximum	18.80%
Annual rent increase percentage	2.50%
Accumulated amortization for property and equipment under capital leases	$ 14,500	13,200
Property [Member]
Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments, Fiscal Year Maturity [Abstract]
2015	1,853
2016	1,899
2017	1,947
2018	1,995
2019	2,045
Remainder	19,364
Total minimum obligations	29,103
Less amounts representing interest (ranging from 5.8% to 18.8%)	(8,370)
Net present value of minimum obligations	20,733
Less current portion	(826)
Long-term capital lease obligations at December 31, 2013	$ 19,907
Property [Member] | Capital Lease Obligations [Member]
Property Subject to or Available for Operating Lease [Line Items]
Term of lease	13 years			20 years
Capital leased property				$ 12,300
Increase in capital leased property	$ 11,700
Capital lease obligations		$ 15,500		$ 12,300
Net book value of capital asset	13,100
Equipment [Member]
Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments, Fiscal Year Maturity [Abstract]
2015	1
2016	1
2017	0
2018	0
2019	0
Remainder	0
Total minimum obligations	2
Less amounts representing interest (ranging from 5.8% to 18.8%)	0
Net present value of minimum obligations	2
Less current portion	(1)
Long-term capital lease obligations at December 31, 2013	$ 1