Consolidated Statement of Financial Position (Parenthetical) (USD $)	Feb. 29, 2012	Feb. 28, 2011
Class A
Common shares, par value	$ 1	$ 1
Common stock, shares issued	83,405,116	82,181,659
Treasury stock, shares	49,393,801	44,711,736
Class B
Common shares, par value	$ 1	$ 1
Common stock, shares issued	6,066,092	6,066,092
Treasury stock, shares	3,223,683	3,128,841