Range of Assumptions for Various Stock Compensation Plans (Detail)	6 Months Ended
	May 31, 2012	May 31, 2011
Assumptions used to Determine Fair Value Options [Line Items]
Risk-free interest rates, minimum	0.10%	0.10%
Risk-free interest rates, maximum	2.20%	3.50%
Dividend yield	2.30%	2.40%
Expected volatility, minimum	16.50%	15.20%
Expected volatility, maximum	21.60%	22.20%
Expected lives	6 years 37 days	6 years 146 days