Shareholders' Equity (Narrative) (Details) - USD ($)	1 Months Ended	12 Months Ended
	Jul. 31, 2013	Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2011	Sep. 30, 2015	Jan. 31, 2014	Nov. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Preferred stock, shares issued		0	0
Preferred stock, shares outstanding		0
Common stock, shares authorized		200,000,000	200,000,000
Common stock, par value (in dollars per share)		$ 0.01	$ 0.01
Common stock, shares issued		50,579,539	50,676,769
Common stock, shares outstanding		50,579,539	50,676,769
Share repurchase program, authorized amount	$ 360,000,000.0					$ 100,000,000.0	$ 100,000,000.0	$ 350,000,000
Increase in common stock repurchase amount	$ 10,000,000.0
Common stock repurchased and retired (in shares)		1,300,000	2,306,000	11,579,000
Common stock repurchased and retired, value (in dollars)		$ 32,868,000	$ 52,604,000	$ 269,469,000
Remaining authorized repurchase amount		$ 14,500,000				$ 114,500,000.0
Deferred Stock Unit [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred stock units, shares outstanding		74,900
Deferred stock unit represents common stock, share		1
Deferred stock units granted in period, shares					21,700