Earnings Per Share - Computation for Basic and Diluted Earnings Per Share (Detail) (USD $)	3 Months Ended		6 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Aug. 31, 2014	Aug. 31, 2013
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	25,990,496	26,102,129	25,991,444	26,078,188
Effect of dilutive options	12,205	26,526	13,105	20,232
Diluted weighted average common shares outstanding	26,002,701	26,128,655	26,004,549	26,098,420
Per share amounts:
Net earnings - basic	$ 0.39	$ 0.38	$ 0.69	$ 0.70
Net earnings - diluted	$ 0.39	$ 0.38	$ 0.69	$ 0.70
Cash dividends	$ 0.175	$ 0.175	$ 0.350	$ 0.175