Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2015	Aug. 31, 2014
Numerator:
Net income for basic and diluted earnings per common share	$ 17,243	$ 13,769	$ 37,167	$ 28,694
Denominator:
Denominator for basic earnings per common share-weighted average shares (shares)	25,782	25,657	25,769	25,640
Effect of dilutive securities:
Employee and Director stock awards (shares)	140	101	123	109
Denominator for diluted earnings per common share (shares)	25,922	25,758	25,892	25,749
Earnings per share basic and diluted:
Basic earnings per Common share (usd per share)	$ 0.67	$ 0.54	$ 1.44	$ 1.12
Diluted earnings per common share (usd per share)	$ 0.67	$ 0.53	$ 1.44	$ 1.11