Revenue from Contracts with Customers (Schedule of Revenue from Contracts with Customers) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Fee revenue and other income:
In-scope of FASB ASC 606 - Invoice processing fees		$ 20,542	$ 19,149
In-scope of FASB ASC 606 - Invoice payment fees		5,915	5,678
Information services payment and processing revenue		26,457	24,827
Bank service fees		376	335
Fee revenue (in-scope of FASB ASC 606)		26,833	25,162
Other income (out-of-scope of FASB ASC 606)		180	212
Total fee revenue and other income		27,013	25,374
Net interest income after provision for loan losses (out-of-scope of FASB ASC 606)	[1]	11,357	10,609
Total net revenue		$ 38,370	$ 35,983

[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; but, is out-of-scope of FASB ASC 606.