Derivative Instruments and Hedging Activities (Details) (USD $) In Thousands, unless otherwise specified	Aug. 31, 2011 item	May 31, 2012 Interest rate cap Derivatives designated as hedging instruments:	Jun. 30, 2011 Interest rate cap Derivatives designated as hedging instruments:	May 31, 2012 Interest rate swap Derivatives designated as hedging instruments:	Jun. 30, 2011 Interest rate swap Derivatives designated as hedging instruments:
Derivative Instruments and Hedging Activities
Number of derivative financial instruments	2
Derivative Instruments and Hedging Activities
Notional amount under revolving credit agreement			$ 50,000		$ 50,000
Fair value carrying amount of the Company's interest rate derivatives
Derivative Assets		249
Derivative Liabilities				$ (4,479)