Earnings Per Share - Computation for Basic and Diluted Earnings (loss) Per Share (Detail) - $ / shares	3 Months Ended				6 Months Ended
	Aug. 31, 2019	May 31, 2019	Aug. 31, 2018	May 31, 2018	Aug. 31, 2019	Aug. 31, 2018
Earnings Per Share [Abstract]
Basic weighted average common shares outstanding	26,029,359		25,671,643		26,034,122	25,510,356
Effect of dilutive options			13,871			12,475
Diluted weighted average common shares outstanding	26,029,359		25,685,514		26,034,122	25,522,831
Earnings per share
Net earnings - basic	$ 0.37		$ 0.37		$ 0.74	$ 0.74
Net earnings - diluted	0.37		0.37		0.74	0.74
Cash dividends	$ 0.225	$ 0.225	$ 0.225	$ 0.20	$ 0.450	$ 0.425