Unaudited Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	[1]	Jun. 30, 2017	Jun. 30, 2016	[1]
Income Statement [Abstract]
Revenues, net	$ 541,237	$ 417,905		$ 1,061,670	$ 832,167
Expenses:
Merchant commissions	30,619	22,308		55,003	50,541
Processing	103,322	80,691		205,146	160,505
Selling	38,957	31,947		77,794	58,500
General and administrative	87,569	63,586		183,003	131,180
Depreciation and amortization	64,709	48,436		129,575	84,764
Other operating, net	18	(231)		38	(446)
Operating income	216,043	171,168		411,111	347,123
Equity method investment loss (income)	2,354	(7,184)		4,731	(4,991)	[2]
Other (income) expense, net	(551)	104		1,645	763
Interest expense, net	23,851	15,900		46,978	32,091
Total other expense	25,654	8,820		53,354	27,863
Income before income taxes	190,389	162,348		357,757	319,260
Provision for income taxes	59,402	46,095		103,077	91,917
Net income	$ 130,987	$ 116,253		$ 254,680	$ 227,343	[2]
Earnings per share:
Basic earnings per share (in dollars per share)	$ 1.42	$ 1.25		$ 2.77	$ 2.46
Diluted earnings per share (in dollars per share)	$ 1.39	$ 1.22		$ 2.70	$ 2.39
Weighted average shares outstanding:
Basic weighted average shares outstanding (in shares)	92,013	92,665		92,060	92,591
Diluted weighted average shares outstanding (in shares)	94,223	95,279		94,392	95,137

[1] Reflects the impact of the Company's adoption of Accounting Standards Update 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, to simplify several aspects of the accounting for share-based compensation, including the income tax consequences.

[2] Reflects the impact of the Company's adoption of Accounting Standards Update 2016-09, Compensation-Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting, to simplify several aspects of the accounting for share-based compensation, including the income tax consequences.