Stock-Based Compensation (Stock-based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 3,056	$ 3,761	$ 9,521	$ 11,423
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	538	920	1,830	2,749
Technology and analytics
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	499	793	1,824	2,437
Processing and servicing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	99	227	429	781
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation	$ 1,920	$ 1,821	$ 5,438	$ 5,456