Revenue from Contracts with Customers (Schedule of Revenue from Contracts with Customers) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fee revenue and other income:
In-scope of FASB ASC 606 - Invoice processing fees		$ 20,447	$ 19,467	$ 40,989	$ 38,616
In-scope of FASB ASC 606 - Invoice payment fees		6,405	5,754	12,320	11,432
Information services payment and processing revenue		26,852	25,221	53,309	50,048
Bank service fees		301	359	677	694
Fee revenue (in-scope of FASB ASC 606)		27,153	25,580	53,986	50,742
Other income (out-of-scope of FASB ASC 606)		219	60	399	272
Total fee revenue and other income		27,372	25,640	54,385	51,014
Net interest income after provision for loan losses (out-of-scope of FASB ASC 606)	[1]	12,022	10,719	23,379	21,328
Total net revenue		$ 39,394	$ 36,359	$ 77,764	$ 72,342

[1] The Company earns interest income from the balances generated during the invoice processing and payment cycle and on deposit accounts, which is an integral component of the Company’s compensation for services provided; but, is out-of-scope of FASB ASC 606.