Restatement of Previously Issued Financial Statements - Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Feb. 28, 2017	Nov. 30, 2016	Aug. 31, 2016	May 31, 2016	Feb. 29, 2016	Nov. 30, 2015	Aug. 31, 2015	May 31, 2015	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net Income	$ 12,270	$ 16,646	$ 10,159	$ 22,189	$ 15,182	$ 22,822	$ 14,866	$ 22,674	$ 61,264	$ 75,544	$ 65,616
Comprehensive Income									62,730	67,816	53,802
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net Income	11,584	18,251	10,023	21,063	16,076	23,547	17,243	19,924	60,921	76,790	64,943
Comprehensive Income									62,387	69,062	53,129
Correction
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net Income	$ 686	$ (1,605)	$ 136	$ 1,126	$ (894)	$ (725)	$ (2,377)	$ 2,750	343	(1,246)	673
Comprehensive Income									$ 343	$ (1,246)	$ 673