Unaudited Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenues, net	$ 577,877	$ 484,426	$ 1,639,547	$ 1,316,593
Expenses:
Merchant commissions	27,687	28,214	82,690	78,755
Processing	111,283	96,233	316,429	256,738
Selling	45,060	34,180	122,854	92,680
General and administrative	92,043	77,904	275,046	209,084
Depreciation and amortization	69,156	57,084	198,731	141,848
Other operating, net	11	(244)	49	(690)
Operating income	232,637	191,055	643,748	538,178
Investment loss (income)	47,766	2,744	52,497	(2,247)
Other (income) expense, net	(175,271)	293	(173,626)	1,056
Interest expense, net	29,344	17,814	76,322	49,905
Loss on extinguishment of debt	3,296	0	3,296	0
Total other (income) expense	(94,865)	20,851	(41,511)	48,714
Income before income taxes	327,502	170,204	685,259	489,464
Provision for income taxes	124,679	40,586	227,756	132,503
Net income	$ 202,823	$ 129,618	$ 457,503	$ 356,961
Earnings per share:
Basic earnings per share (in dollars per share)	$ 2.23	$ 1.40	$ 4.99	$ 3.85
Diluted earnings per share (in dollars per share)	$ 2.18	$ 1.36	$ 4.87	$ 3.75
Weighted average shares outstanding:
Basic weighted average shares outstanding (in shares)	90,751	92,631	91,619	92,604
Diluted weighted average shares outstanding (in shares)	93,001	95,307	93,923	95,204