Business Combinations (Pro Forma) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Business Acquisition, Pro Forma Information
Operating revenue	$ 128,643	$ 92,800	$ 361,499	$ 259,290
Net Income (Loss) Attributable to Parent	$ 29,242	$ 24,184	$ 84,630	$ 74,045
Basic EPS	$ 0.93	$ 0.77	$ 2.69	$ 2.34
Diluted EPS	$ 0.92	$ 0.76	$ 2.67	$ 2.33
Revenue, Net, Increase (Decrease)	$ 35,843		$ 102,209
Revenue, Net, Increase (Decrease), Percentage	39.40%		38.60%
Operating revenue	$ 128,643	$ 92,800	$ 361,499	$ 259,290
Parent, ItzCAsh, beBetter, YouFirst, WallStreet, PML, Via, and Transcorp [Member]
Business Acquisition, Pro Forma Information
Revenue, pro forma	129,081	141,057	401,295	425,413
Net income, pro forma	$ 29,097	$ 26,434	$ 86,742	$ 86,060
Basic EPS, pro forma	$ 0.92	$ 0.84	$ 2.76	$ 2.72
Diluted EPS, pro forma	$ 0.92	$ 0.84	$ 2.74	$ 2.71
Business Acquisition, Pro Forma Revenue, Increase (Decrease), Percentage	(8.50%)		(5.70%)