Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Revenues, net	$ 295,283	$ 225,150	$ 822,693	$ 639,670
Expenses:
Merchant commissions	25,014	16,944	62,964	50,360
Processing	41,451	33,473	117,152	95,426
Selling	17,950	13,859	52,885	38,949
General and administrative	40,947	31,559	122,304	91,774
Depreciation and amortization	25,714	18,060	74,561	48,579
Operating income	144,207	111,255	392,827	314,582
Other expense (income), net	594	(156)	870	130
Interest expense, net	4,859	3,756	15,628	10,960
Equity method investment loss	2,200		3,689
Total other expense	7,653	3,600	20,187	11,090
Income before taxes	136,554	107,655	372,640	303,492
Provision for income taxes	41,045	29,035	113,473	87,111
Net income	$ 95,509	$ 78,620	$ 259,167	$ 216,381
Earnings per share:
Basic earnings per share	$ 1.14	$ 0.96	$ 3.12	$ 2.65
Diluted earnings per share	$ 1.11	$ 0.93	$ 3.02	$ 2.56
Weighted average shares outstanding:
Basic weighted average shares outstanding	83,611	81,974	83,118	81,592
Diluted weighted average shares outstanding	86,134	84,905	85,688	84,446