Derivative Instruments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010
Options Held [Member]
Derivative [Line Items]
Maximum maturity period, foreign currency derivative (in years)	1 year
Gains (losses) on foreign currency option contracts		$ (0.5)	$ 3.1
Foreign currency option contracts expiration term (in years)	1 year
Forward Contracts [Member]
Derivative [Line Items]
Maximum maturity period, foreign currency derivative (in years)	90 days
Gains (losses) on foreign currency option contracts	$ (0.2)	$ (1.2)	$ (7.2)