Stock Repurchase Programs (Narrative) (Details) (USD $) Share data in Thousands, except Per Share data	3 Months Ended		9 Months Ended		0 Months Ended	9 Months Ended
	Aug. 31, 2011	Aug. 31, 2010	Aug. 31, 2011	Aug. 31, 2010	Dec. 21, 2010 December 2010 Plan [Member]	Aug. 31, 2011 December 2010 Plan [Member]	Aug. 31, 2011 Retained Earnings [Member]	Aug. 31, 2011 Additional Paid-In Capital [Member]
Stock repurchase program, authorized amount					$ 300,000,000
Remaining repurchase amount authorized from new program						154,800,000
Payments classification for shares repurchased	$ 72,888,000	$ 34,056,000	$ 145,216,000	$ 101,538,000			$ 60,500,000	$ 84,700,000
Shares repurchased	2,565	2,736	5,425	9,324		500
Average price per share	$ 28.41	$ 12.45	$ 26.77	$ 10.89		$ 21.53