Stock-Based Compensation (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Feb. 29, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of executives whose employment was terminated	1
Additional stock-based compensation expenses related to separation and acceleration vesting	$ 0.6
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period of awards (in years)	3
Restricted Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period of awards (in years)	3
Minimum [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period of awards (in years)	4
Maximum [Member] | Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period of awards (in years)	5