Earnings Per Share - Computation for Basic and Diluted Earnings (loss) per Share (Detail) - $ / shares	3 Months Ended		9 Months Ended
	Nov. 30, 2018	Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2017
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	26,189,917	25,360,452	25,744,344	25,387,389
Effect of dilutive options	12,513	33,030	12,487	21,870
Diluted weighted average common shares outstanding	26,202,430	25,393,482	25,756,831	25,409,259
Earnings per share
Net earnings - basic	$ 0.40	$ 0.33	$ 1.14	$ 0.97
Net earnings - diluted	0.40	0.33	1.14	0.97
Cash dividends	$ 0.225	$ 0.200	$ 0.650	$ 0.575