Note 13. Employee Stock Option and Retirement Plans (Detail) - Summary of Share-Based Awards Available for Grant	3 Months Ended
	Feb. 29, 2012	Nov. 30, 2011
Employee Option Plan [Member] | Non-Performance Based [Member]
Share-based awards granted		(666,000)
Employee Option Plan [Member] | Performance Based [Member]
Share-based awards granted		(420,000)
Employee Option Plan [Member] | Non-Employee Directors [Member]
Share-based awards granted	0
Employee Option Plan [Member]
Balance	3,922,000	4,977,000
Share-based awards canceled/forfeited	16,000	31,000
Balance	3,938,000	3,922,000
Non-Employee Directors Plan [Member] | Non-Performance Based [Member]
Share-based awards granted		0
Non-Employee Directors Plan [Member] | Performance Based [Member]
Share-based awards granted		0
Non-Employee Directors Plan [Member] | Non-Employee Directors [Member]
Share-based awards granted	(21,000)
Non-Employee Directors Plan [Member]
Balance	147,000	147,000
Share-based awards canceled/forfeited	0	0
Balance	126,000	147,000