Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenues, net	$ 2,249,538	$ 1,831,546	$ 1,702,865
Expenses:
Merchant commissions	113,133	104,345	108,257
Processing	429,613	355,414	331,073
Selling	170,717	131,443	109,075
General and administrative	387,694	283,625	297,715
Depreciation and amortization	264,560	203,256	193,453
Other operating, net	61	(690)	(4,242)
Operating income	883,760	754,153	667,534
Investment loss	53,164	36,356	57,668
Other (income) expense, net	(173,436)	2,982	2,523
Interest expense, net	107,146	71,896	71,339
Loss on extinguishment of debt	3,296	0	0
Total other (income) expense	(9,830)	111,234	131,530
Income before income taxes	893,590	642,919	536,004
Provision for income taxes	153,390	190,534	173,573
Net income	$ 740,200	$ 452,385	$ 362,431
Earnings per share:
Basic earnings per share (in usd per share)	$ 8.12	$ 4.89	$ 3.94
Diluted earnings per share (in usd per share)	$ 7.91	$ 4.75	$ 3.85
Weighted average shares outstanding:
Basic weighted average shares outstanding (in shares)	91,129	92,597	92,023
Diluted weighted average shares outstanding (in shares)	93,594	95,213	94,139