Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies
Operating leases term, low end of range	1 year
Operating leases term, high end of range	5 years
Total lease and rent expense	$ 2,307	$ 2,227	$ 2,000
Future minimum payments under operating leases
2016	1,718
2017	1,242
2018	762
2019	688
2020	377
Thereafter	$ 197