Derivative Instruments And Hedging Activities (Narrative) (Details) (USD $)	3 Months Ended
Aug. 31, 2011
Derivative Instruments And Hedging Activities
Losses in accumulated other comprehensive income expected to be reclassified into net earnings	$ 1,410,000
Losses in accumulated other comprehensive income expected to be reclassified into net earnings, net of tax	$ 760,000

Name:

us-gaap_DerivativeInstrumentsGainLossReclassificationFromAccumulatedOCIToIncomeEstimatedNetAmountToBeTransferred

Namespace Prefix:

us-gaap

Data Type:

xbrli:monetaryItemType

Balance Type:

credit

Period Type:

duration