Summary of Significant Accounting Policies - Reserve for Operating Losses (Details) (USD $)			3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Feb. 28, 2014 Allowance For Operating Losses [Member]	May 31, 2013 Allowance For Operating Losses [Member]	Feb. 28, 2014 Allowance For Uncollectible Customer's Liability - Merchant Card Processing Services [Member]	Feb. 28, 2013 Allowance For Uncollectible Customer's Liability - Merchant Card Processing Services [Member]	Feb. 28, 2014 Allowance For Uncollectible Customer's Liability - Merchant Card Processing Services [Member]	Feb. 28, 2013 Allowance For Uncollectible Customer's Liability - Merchant Card Processing Services [Member]	Feb. 28, 2014 Reserve for operating losses-Check guarantee processing [Member] Cost of Services [Member]	Feb. 28, 2013 Reserve for operating losses-Check guarantee processing [Member] Cost of Services [Member]	Feb. 28, 2014 Reserve for operating losses-Check guarantee processing [Member] Cost of Services [Member]	Feb. 28, 2013 Reserve for operating losses-Check guarantee processing [Member] Cost of Services [Member]	Feb. 28, 2014 Reserve for operating losses-Check guarantee processing [Member] Other Receivables, Net, Current [Member]	May 31, 2013 Reserve for operating losses-Check guarantee processing [Member] Other Receivables, Net, Current [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Reserves for processing obligations	$ 2,104,000	$ 2,318,000
Valuation and allowance charges			1,500,000	2,000,000	4,600,000	7,300,000	2,500,000	2,700,000	9,600,000	9,400,000
Valuation and allowance reserve											$ 3,200,000	$ 3,100,000