Derivative Instruments (Outstanding Foreign Currency Forward Contracts) (Details) (USD $) In Thousands, unless otherwise specified	May 31, 2012	Nov. 30, 2011
Derivative [Line Items]
Total, Notional Value	$ 47,607	$ 38,455
Total, Fair Value	(172)	52
Forward contracts to sell U.S. dollars [Member]
Derivative [Line Items]
Foreign currency derivative contracts to sell U.S. dollars, Notional Value	4,717	2,180
Foreign currency derivative contracts to purchase U.S. dollars, Fair Value	20	(54)
Forward contracts to purchase U.S. dollars [Member]
Derivative [Line Items]
Foreign currency derivative contracts to purchase U.S. dollars, Notional Value	42,890	36,275
Foreign currency derivative contracts to purchase U.S. dollars, Fair Value	$ (192)	$ 106