Property, Equipment and Software (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Software, Gross	$ 5,761	$ 4,836
Property, Plant and Equipment, Software Gross	15,466	14,186
Less: accumulated depreciation	(4,928)	(4,060)
Less: accumulated amortization	(2,020)	(2,278)
Total property, equipment and software, net	8,518	7,848
Furniture
Property, Plant and Equipment [Line Items]
Total property, equipment and software, at cost	2,873	2,704
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property, equipment and software, at cost	3,785	3,659
Computer hardware
Property, Plant and Equipment [Line Items]
Total property, equipment and software, at cost	$ 3,047	$ 2,987