Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			9 Months Ended
	Feb. 28, 2014	Feb. 28, 2013		Feb. 28, 2014 segment	Feb. 28, 2013
Segment Reporting Information [Line Items]
Number of reportable segments				2
Revenues	$ 616,452	$ 578,746		$ 1,880,259	$ 1,757,571
Operating income (loss) for segments	97,291	90,774		316,582	287,844
Depreciation and amortization	29,806	30,892		87,198	82,947
Processing system intrusion expense (credit)	0	(1,189)		(7,000)	8,311
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	616,452	578,746		1,880,259	1,757,571
Corporate [Member]
Segment Reporting Information [Line Items]
Operating income (loss) for segments	(22,481)	(16,524)	[1]	(67,334)	(64,912)	[1]
Depreciation and amortization	1,594	1,478		4,776	3,851
North America merchant services [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	429,347	408,572		1,326,885	1,256,135
Operating income (loss) for segments	61,695	55,478		201,831	189,809
Depreciation and amortization	14,422	14,267		41,488	36,092
International merchant services [member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	187,105	170,174		553,374	501,436
Operating income (loss) for segments	58,077	51,820		182,085	162,947
Depreciation and amortization	13,790	15,147		40,934	43,004
United States [Member] | North America merchant services [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	355,880	336,354		1,081,506	1,022,250
Canada [member] | North America merchant services [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	73,467	72,218		245,379	233,885
Europe [Member] | International merchant services [member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	143,832	130,750		433,886	390,376
Asia-Pacific [Member] | International merchant services [member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	$ 43,273	$ 39,424		$ 119,488	$ 111,060

[1] Includes a processing system intrusion credit of $1.2 million for the three months ended February 28, 2013. Includes a processing system intrusion credit of $7.0 million and a charge of $8.3 million for the nine months ended February 28, 2014 and February 28, 2013, respectively.