Business and Intangible Asset Acquisitions (Details)						12 Months Ended				12 Months Ended				0 Months Ended						12 Months Ended						12 Months Ended		12 Months Ended					12 Months Ended						12 Months Ended
	May 31, 2012 USD ($)	May 31, 2011 USD ($)	May 31, 2010 USD ($)	May 31, 2012 Alfa [Member] USD ($)	Dec. 05, 2011 Alfa [Member] USD ($)	May 31, 2012 HSBC Malta [Member] USD ($)	Dec. 30, 2011 HSBC Malta [Member] USD ($)	May 31, 2012 CyberSource [Member]	Jan. 31, 2012 CyberSource [Member] USD ($)	May 31, 2011 Comercia [Member] USD ($)	May 31, 2011 Comercia [Member] EUR (€)	Dec. 20, 2010 Comercia [Member] USD ($)	Dec. 20, 2010 Comercia [Member] EUR (€)	Jun. 12, 2009 HSBC Merchant Services LLP [Member] USD ($)	Jun. 30, 2008 HSBC Merchant Services LLP [Member] USD ($)	Sep. 28, 2009 Auctionpay, Inc. [Member] USD ($)	Apr. 21, 2010 HealthCard Systems / NationalCard Processing Systems [Member] USD ($)	Mar. 31, 2010 Other Acquisition [Member] USD ($)	May 31, 2011 Various Contract-Based and Customer Related Intangible Assets [Member]	May 31, 2012 Customer-related Alfa [Member] USD ($) Y	May 31, 2012 Customer-related HSBC Malta [Member] USD ($) Y	May 31, 2012 Customer-related CyberSource [Member] Y	May 31, 2011 Customer-related Comercia [Member] USD ($) Y	May 31, 2010 Customer-related Auctionpay, Inc. [Member] Y	Sep. 28, 2009 Customer-related Auctionpay, Inc. [Member] USD ($)	May 31, 2010 Customer-related HealthCard Systems / NationalCard Processing Systems [Member] Y	Apr. 21, 2010 Customer-related HealthCard Systems / NationalCard Processing Systems [Member] USD ($)	May 31, 2012 Contract-based HSBC Malta [Member] USD ($) Y	May 31, 2011 Contract-based Comercia [Member] USD ($) Y	May 31, 2010 Contract-based Auctionpay, Inc. [Member] Y	Sep. 28, 2009 Contract-based Auctionpay, Inc. [Member] USD ($)	Apr. 21, 2010 Contract-based HealthCard Systems / NationalCard Processing Systems [Member] USD ($)	May 31, 2010 Contract-based Other Acquisition [Member] Y	May 31, 2010 Trademark Auctionpay, Inc. [Member] Y	Sep. 28, 2009 Trademark Auctionpay, Inc. [Member] USD ($)	May 31, 2012 North America merchant services [Member] USD ($)	May 31, 2011 North America merchant services [Member] USD ($)	May 31, 2010 North America merchant services [Member] USD ($)	May 31, 2011 UNITED STATES North America merchant services [Member] Contractural rights and customer relationships [Member] USD ($)
Business Acquisition [Line Items]
Percentage of controlling financial interest acquired				100.00%		100.00%		100.00%				51.00%	51.00%		51.00%	100.00%	100.00%		100.00%
Remaining noncontrolling interest purchased by parent, percentage														49.00%
Cost of acquired entity, cash paid					$ 14,100,000		$ 14,500,000						€ 125,000,000			$ 22,000,000
Purchase Price Allocation [Abstract]
Goodwill	724,687,000	779,637,000	569,090,000	3,021,000		6,341,000				147,535,000						11,827,000	5,838,000																			211,102,000	217,422,000	210,065,000
Intangible assets																				7,004,000	4,543,000		96,100,000		4,900,000		5,710,000	2,796,000	54,141,000		1,200,000	120,000			300,000
Fixed assets				1,137,000		798,000										4,815,000
Working capital, net										8,476,000						(201,000)
Other assets				2,888,000
Total assets acquired										306,252,000						23,042,000
Liabilities																(841,000)
Non-controlling interest										(132,738,000)
Net assets acquired, less noncontrolling interest										173,514,000
Net assets acquired				14,050,000		14,478,000										22,000,000	11,668,000
Intangible assets, useful lives (in years)																				10	16	10	10	14		7		10	20	2			5	8
Marketing alliance agreement, term						10 years				20 years	20 years
Remaining noncontrolling interest purchased by parent														307,700,000
Purchase price									14,900,000			173,500,000	128,300,000		438,600,000		11,700,000
Ownership percentage by noncontrolling owners												49.00%	49.00%	0.00%
Proceeds from contributed capital											6,400,000
Expensed acquisition costs										1,000,000
Acquired intangible assets																		800,000																					3,500,000
Intangible assets, useful life, minimum (in years)																																							5
Intangible assets, useful life, maximum (in years)																																							7
Deferred tax asset recorded														$ 90,000,000