Software Development Costs (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Software Development Costs
Gross capitalized software costs	$ 7,988		$ 7,988		$ 6,501
Accumulated amortization	3,962		3,962		3,151
Amortization expense	411	$ 250	811	$ 455
Capitalized software costs not yet subject to amortization	$ 2,124		$ 2,124		$ 911