Loans Modified Troubled Debt Restructuring Subsequently Defaulted (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2013 Contract		Mar. 31, 2012 Contract
Financing Receivable, Modifications [Line Items]
Number of Modified Loans	4	[1]	45	[1]
Unpaid Principal Balance (at period end)	$ 955	[1],[2]	$ 58,840	[1],[2]
Residential
Financing Receivable, Modifications [Line Items]
Number of Modified Loans			11	[1]
Unpaid Principal Balance (at period end)			1,830	[1],[2]
Commercial and industrial
Financing Receivable, Modifications [Line Items]
Number of Modified Loans			7	[1]
Unpaid Principal Balance (at period end)			1,083	[1],[2]
Land and construction
Financing Receivable, Modifications [Line Items]
Number of Modified Loans			4	[1]
Unpaid Principal Balance (at period end)			36,100	[1],[2]
Multi-family
Financing Receivable, Modifications [Line Items]
Number of Modified Loans			6	[1]
Unpaid Principal Balance (at period end)			8,747	[1],[2]
Retail/office
Financing Receivable, Modifications [Line Items]
Number of Modified Loans	2	[1]	9	[1]
Unpaid Principal Balance (at period end)	374	[1],[2]	9,233	[1],[2]
Other commercial real estate
Financing Receivable, Modifications [Line Items]
Number of Modified Loans	2	[1]	4	[1]
Unpaid Principal Balance (at period end)	581	[1],[2]	1,543	[1],[2]
Other consumer
Financing Receivable, Modifications [Line Items]
Number of Modified Loans			4	[1]
Unpaid Principal Balance (at period end)			$ 304	[1],[2]

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

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