Derivative Financial Instruments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Mar. 31, 2012
Derivative Assets | Interest Rate Lock Commitments | Other Assets
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Notional Amount	$ 53,169	[1],[2]	$ 115,032	[1],[2]
Estimated Fair Value	689	[1],[2]	943	[1],[2]
Derivative Assets | Forward Contracts To Sell Mortgage Loans | Other Liabilities
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Notional Amount	10,000	[3],[4]	50,000	[3],[4]
Estimated Fair Value	1	[3],[4]	98	[3],[4]
Derivative Liabilities | Interest Rate Lock Commitments | Other Liabilities
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Notional Amount	559	[2],[5]	27,689	[2],[5]
Estimated Fair Value	3	[2],[5]	72	[2],[5]
Derivative Liabilities | Forward Contracts To Sell Mortgage Loans | Other Liabilities
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Notional Amount	50,000	[4],[6]	105,000	[4],[6]
Estimated Fair Value	$ 313	[4],[6]	$ 557	[4],[6]

[1] The unpaid principal balance is inclusive of all partial paydowns and charge-offs since the modification date.

[2] Interest rate lock commitments include $35.8 million and $118.3 million of commitments not yet approved in the credit underwriting process at March 31, 2013 and 2012, respectively, yet represent potential interest rate risk exposure to the extent of those mortgage loan applications eventually approved for funding.

[3] Non-accrual education loans represent the portion of these loans 90+ days past due that are not covered by a guarantee provided by government agencies that is limited to approximately 97% of the outstanding balance.

[4] The Corporation has elected to offset the fair value of individual forward sale contracts and present a net amount on the Consolidated Balance Sheets in accordance with ASC 815-45, Derivatives and Hedging.

[5] Loans modified in a TDR that were fully paid down, charged-off or foreclosed upon by period end are not reported in this table.

[6] Total risk-based capital divided by total risk-weighted assets.