Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans Allowance for Loan Losses, Allowance for Losses on Lending-Related Commitments and Impaired Loans (Summary Of The Post-Modification Balance Of Loans Restructured) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				12 Months Ended
	Mar. 31, 2014 contracts		Mar. 31, 2013 contracts		Mar. 31, 2014		Mar. 31, 2013
Financing Receivable, Modifications [Line Items]
Restructured loans	$ 5,245	[1],[2]	$ 2,277	[1],[2]	$ 25,648	[1],[3]	$ 35,106	[1],[3]
Troubled debt restructuring modifications, number of count	6	[1],[2]	14	[1],[2]	27	[1],[3]	58	[1],[3]
Extension at Below Market Terms [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	3,972	[1]	1,835	[1]
Troubled debt restructuring modifications, number of count	5	[1]	11	[1]
Reduction of Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	3,877	[1]	2,106	[1]
Troubled debt restructuring modifications, number of count	3	[1]	11	[1]
Modification to Interest Only Payments [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	2,439	[1]	308	[1]
Troubled debt restructuring modifications, number of count	3	[1]	3	[1]
Forgiveness of Debt [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	73	[1]
Troubled debt restructuring modifications, number of count	0	[1]	1	[1]
Commercial | Commercial and industrial
Financing Receivable, Modifications [Line Items]
Restructured loans	88	[1],[2]	708	[1],[2]	88	[1],[3]	14,901	[1],[3]
Troubled debt restructuring modifications, number of count	1	[1],[2]	6	[1],[2]	1	[1],[3]	21	[1],[3]
Commercial | Commercial and industrial | Extension at Below Market Terms [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	88	[1]	573	[1]
Troubled debt restructuring modifications, number of count	1	[1]	5	[1]
Commercial | Commercial and industrial | Reduction of Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	553	[1]
Troubled debt restructuring modifications, number of count	0	[1]	4	[1]
Commercial | Commercial and industrial | Modification to Interest Only Payments [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	88	[1]	185	[1]
Troubled debt restructuring modifications, number of count	1	[1]	2	[1]
Commercial | Commercial and industrial | Forgiveness of Debt [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]
Commercial real-estate | Land
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1],[2]	287	[1],[2]	2,352	[1],[3]	4,131	[1],[3]
Troubled debt restructuring modifications, number of count	0	[1],[2]	2	[1],[2]	1	[1],[3]	5	[1],[3]
Commercial real-estate | Land | Extension at Below Market Terms [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	287	[1]
Troubled debt restructuring modifications, number of count	0	[1]	2	[1]
Commercial real-estate | Land | Reduction of Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	287	[1]
Troubled debt restructuring modifications, number of count	0	[1]	2	[1]
Commercial real-estate | Land | Modification to Interest Only Payments [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]
Commercial real-estate | Land | Forgiveness of Debt [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	73	[1]
Troubled debt restructuring modifications, number of count	0	[1]	1	[1]
Commercial real-estate | Industrial
Financing Receivable, Modifications [Line Items]
Restructured loans	1,078	[1],[2]	0	[1],[2]	2,027	[1],[3]	727	[1],[3]
Troubled debt restructuring modifications, number of count	1	[1],[2]	0	[1],[2]	2	[1],[3]	1	[1],[3]
Commercial real-estate | Industrial | Extension at Below Market Terms [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	1,078	[1]	0	[1]
Troubled debt restructuring modifications, number of count	1	[1]	0	[1]
Commercial real-estate | Industrial | Reduction of Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]
Commercial real-estate | Industrial | Modification to Interest Only Payments [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	1,078	[1]	0	[1]
Troubled debt restructuring modifications, number of count	1	[1]	0	[1]
Commercial real-estate | Industrial | Forgiveness of Debt [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]
Commercial real-estate | Retail
Financing Receivable, Modifications [Line Items]
Restructured loans	202	[1],[2]	200	[1],[2]	202	[1],[3]	5,085	[1],[3]
Troubled debt restructuring modifications, number of count	1	[1],[2]	1	[1],[2]	1	[1],[3]	4	[1],[3]
Commercial real-estate | Retail | Extension at Below Market Terms [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	202	[1]	200	[1]
Troubled debt restructuring modifications, number of count	1	[1]	1	[1]
Commercial real-estate | Retail | Reduction of Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	200	[1]
Troubled debt restructuring modifications, number of count	0	[1]	1	[1]
Commercial real-estate | Retail | Modification to Interest Only Payments [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]
Commercial real-estate | Retail | Forgiveness of Debt [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]
Commercial real-estate | Multi-family
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1],[2]	705	[1],[2]	0	[1],[3]	1,085	[1],[3]
Troubled debt restructuring modifications, number of count	0	[1],[2]	1	[1],[2]	0	[1],[3]	2	[1],[3]
Commercial real-estate | Multi-family | Extension at Below Market Terms [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	705	[1]
Troubled debt restructuring modifications, number of count	0	[1]	1	[1]
Commercial real-estate | Multi-family | Reduction of Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	705	[1]
Troubled debt restructuring modifications, number of count	0	[1]	1	[1]
Commercial real-estate | Multi-family | Modification to Interest Only Payments [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]
Commercial real-estate | Multi-family | Forgiveness of Debt [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]
Commercial real-estate | Mixed use and other
Financing Receivable, Modifications [Line Items]
Restructured loans	3,877	[1],[2]	0	[1],[2]	8,919	[1],[3]	6,061	[1],[3]
Troubled debt restructuring modifications, number of count	3	[1],[2]	0	[1],[2]	9	[1],[3]	12	[1],[3]
Commercial real-estate | Mixed use and other | Extension at Below Market Terms [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	2,604	[1]	0	[1]
Troubled debt restructuring modifications, number of count	2	[1]	0	[1]
Commercial real-estate | Mixed use and other | Reduction of Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	3,877	[1]	0	[1]
Troubled debt restructuring modifications, number of count	3	[1]	0	[1]
Commercial real-estate | Mixed use and other | Modification to Interest Only Payments [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	1,273	[1]	0	[1]
Troubled debt restructuring modifications, number of count	1	[1]	0	[1]
Commercial real-estate | Mixed use and other | Forgiveness of Debt [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]
Residential real estate and other
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1],[2]	377	[1],[2]	1,919	[1],[3]	969	[1],[3]
Troubled debt restructuring modifications, number of count	0	[1],[2]	4	[1],[2]	6	[1],[3]	10	[1],[3]
Residential real estate and other | Extension at Below Market Terms [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	70	[1]
Troubled debt restructuring modifications, number of count	0	[1]	2	[1]
Residential real estate and other | Reduction of Interest Rate [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	361	[1]
Troubled debt restructuring modifications, number of count	0	[1]	3	[1]
Residential real estate and other | Modification to Interest Only Payments [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	0	[1]	123	[1]
Troubled debt restructuring modifications, number of count	0	[1]	1	[1]
Residential real estate and other | Forgiveness of Debt [Member]
Financing Receivable, Modifications [Line Items]
Restructured loans	$ 0	[1]	$ 0	[1]
Troubled debt restructuring modifications, number of count	0	[1]	0	[1]

[1] Balances represent the recorded investment in the loan at the time of the restructuring.

[2] TDRs may have more than one modification representing a concession. As such, TDRs during the period may be represented in more than one of the categories noted above.

[3] Total TDRs represent all loans restructured in TDRs during the previous twelve months from the date indicated.