Fair Value Measurements Reconciliation of Beginning and Ending Balances for Fair Value Measurements using Significant Unobservable Inputs (Detail) (Available For Sale Securities, USD $) In Thousands, unless otherwise specified	6 Months Ended
	Aug. 31, 2014	Aug. 31, 2013	Nov. 30, 2012	Feb. 29, 2012
Available For Sale Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 6,750		$ 6,750	$ 6,500
Purchases	0	250
Ending Balance	$ 6,750		$ 6,750	$ 6,500