Commitments and Contingencies (Details) (Garden City lease, USD $) In Millions, unless otherwise specified	0 Months Ended
	Oct. 03, 2003	May 31, 2014	May 31, 2013
Garden City lease
Sale-leaseback transaction
Net proceeds from sale of facility	$ 14.0
Cost of the facility	9.5
Accumulated depreciation of the facility	4.6
Deferred gain realized on the sale	9.1
Deferred gain amortization period	20 years
Unamortized balance of the deferred gain		$ 4.3	$ 4.8