Settlement Processing Assets and Obligations (Details) (USD $) In Thousands, unless otherwise specified	May 31, 2014	May 31, 2013
Offsetting Assets [Line Items]
Total	$ 780,917	$ 259,204
Total	(451,317)	(162,558)
Merchant Reserves [Member]
Offsetting Assets [Line Items]
Merchant Reserves	(79,547)	(57,409)
Reserves for processing obligations	(96,622)	(223,314)
Allowance For Operating Losses [Member]
Offsetting Assets [Line Items]
Reserves for processing obligations	(1,725)	(2,318)
Allowance for Trade Receivables [Member]
Offsetting Assets [Line Items]
Reserves for processing obligations	(601)	(961)
Interchange Reimbursement [Member]
Offsetting Assets [Line Items]
Settlement processing assets, gross	217,806	70,348
Settlement processing obligations, gross	54,459	200,319
(Liability To) Receivable From Members [Member]
Offsetting Assets [Line Items]
Settlement processing assets, gross	206,322	117,404
Settlement processing obligations, gross	(5,490)	(27,717)
Liability to Merchants [Member]
Offsetting Assets [Line Items]
Settlement processing obligations, gross	(407,651)	(120,875)
Receivables From Card Networks [Member]
Offsetting Assets [Line Items]
Settlement processing assets, gross	430,763	126,136
Exceptional Items [Member]
Offsetting Assets [Line Items]
Settlement processing assets, gross	5,573	2,725
Settlement processing obligations, gross	$ 6,313	$ 12,308