Income Tax - Reconciliation (Details)	12 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2012
Income Tax Disclosure [Abstract]
Federal statutory rate	35.00%	35.00%	35.00%
State income taxes, net of federal income tax benefit	0.90%	0.90%	0.50%
Foreign income taxes	(7.20%)	(7.00%)	(6.30%)
Foreign interest income not subject to tax	(2.10%)	(2.80%)	(2.20%)
Tax credits and other	3.10%	3.70%	1.80%
Effective tax rate attributable to Global Payments	29.70%	29.80%	28.80%
Noncontrolling interests	(1.20%)	(1.20%)	(1.20%)
Effective tax rate	28.50%	28.60%	27.60%