Net Carrying Values of Debt Securities by Contractual Maturity (Detail) (USD $) In Thousands, unless otherwise specified	Feb. 28, 2013
Available-for-Sale Securities, amortized cost
Less than one year, amortized cost	$ 2,073
One year through five years, amortized cost	28,532
Six years through ten years, amortized cost	4,559
After ten years, amortized cost	1,811
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Total	36,975
Available-for-Sale Securities, fair value
Less than one year, fair value	2,088
One year through five years, fair value	26,048
Six years through ten years, fair value	4,690
After ten years, fair value	2,035
Available-for-sale Securities, Debt Securities, Total	$ 34,861

Amount of available-for-sale debt securities at cost, net of adjustments, maturing in the sixth fiscal year through the tenth fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings (less any cumulative-effect adjustments, as defined) and fair value hedge accounting adjustments.

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