Stock-Based Compensation and Employee Benefit Plans (Stock-based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 15,915	$ 11,582	$ 2,842
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	4,002	3,081	686
Technology and analytics
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	3,199	2,351	539
Processing and servicing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	1,092	775	219
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 7,622	$ 5,375	$ 1,398