Intangible Assets (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) item	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Intangible Assets
Weighted-Average Amortization Period	10 years
Gross Carrying Amount	$ 10,427	$ 10,427
Accumulated Amortization	$ (6,899)	(5,838)
Number of other patterns | item	0
Amortization expense	$ 1,061	$ 1,061	$ 1,061
2016	1,100
2017	1,100
2018	1,100
2019	$ 300