Goodwill and Intangible Assets - Goodwill Rollforward (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Feb. 28, 2014	May 31, 2013
Goodwill [Line Items]
Goodwill, gross		$ 1,044,222
Accumulated impairment losses		0
Goodwill [Roll Forward]
Goodwill, balance at beginning of period	1,044,222
Goodwill acquired	0
Effect of foreign currency translation	20,646
Goodwill, balance at end of period	1,064,868
North America merchant services [Member]
Goodwill [Line Items]
Goodwill, gross		519,175
Accumulated impairment losses		0
Goodwill [Roll Forward]
Goodwill, balance at beginning of period	519,175
Goodwill acquired	0
Effect of foreign currency translation	(5,891)
Goodwill, balance at end of period	513,284
International merchant services [member]
Goodwill [Line Items]
Goodwill, gross		525,047
Accumulated impairment losses		0
Goodwill [Roll Forward]
Goodwill, balance at beginning of period	525,047
Goodwill acquired	0
Effect of foreign currency translation	26,537
Goodwill, balance at end of period	$ 551,584