Pension Plan (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Aug. 31, 2012	Aug. 31, 2011	Aug. 31, 2012	Aug. 31, 2011
Components of net periodic benefit cost
Service cost	$ 320	$ 303	$ 641	$ 607
Interest cost	601	630	1,201	1,261
Expected return on plan assets	(802)	(803)	(1,604)	(1,607)
Amortization of:
Prior service cost	(36)	(36)	(72)	(72)
Unrecognized net loss	456	316	912	631
Net periodic benefit cost	$ 539	$ 410	$ 1,078	$ 820