Maturities of Securities Available For Sale (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012
Investments Classified by Contractual Maturity Date [Line Items]
Due in 1 year or less	$ 26,117
Due in 1 to 5 years	20,664
Due in 5 to 10 years	42,812
Due in over 10 years	84,625
Mortgage-backed securities	320,081
Total	494,299
Due in 1 year or less	26,249
Due in 1 to 5 years	20,727
Due in 5 to 10 years	43,184
Due in over 10 years	85,084
Mortgage-backed securities	322,362
Total	$ 497,606

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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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