Long-Term Debt - FV, Limit, Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	May 31, 2016	May 31, 2015
Long-term debt
Limit on additional debt borrowings	$ 153,390
INTEREST EXPENSE
Deferred finance costs	290	$ 291
Total interest expense	3,651	$ 2,892
3.90% unsecured Senior Notes payable | Book value
Long-term debt
Long-term debt	39,550
3.90% unsecured Senior Notes payable | Fair Values | Significant Other Observable Market Inputs (Level 2) | Discounted cash flow analysis
Long-term debt
Long-term debt	$ 40,320