Allowance For Loan Losses, Allowance For Losses On Lending-Related Commitments And Impaired Loans (Summary Of Loans Restructured And Subsequently Defaulted Under The Restructured Terms) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013 Loan		Jun. 30, 2012 Loan		Jun. 30, 2013 Loan		Jun. 30, 2012 Loan
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					$ 28,921	[1],[2]	$ 118,360	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	14	[1],[3]	25	[1],[3]	14	[1],[3]	30	[1],[3]
Count					51	[1],[2]	129	[1],[2]
Balance	4,562	[1],[3]	11,661	[1],[3]	4,562	[1],[3]	16,628	[1],[3]
Residential Real Estate And Other [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					1,341	[1],[2]	6,397	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	5	[1],[3]	7	[1],[3]	5	[1],[3]	8	[1],[3]
Count					12	[1],[2]	18	[1],[2]
Balance	563	[1],[3]	2,273	[1],[3]	563	[1],[3]	2,722	[1],[3]
Commercial Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					496	[1],[2]	2,756	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts		[1],[3]	0	[1],[3]	0	[1],[3]	0	[1],[3]
Count					1	[1],[2]	3	[1],[2]
Balance	0	[1],[3]	0	[1],[3]	0	[1],[3]	0	[1],[3]
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					6,120	[1],[2]	3,827	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	[1],[3]	5	[1],[3]	0	[1],[3]	5	[1],[3]
Count					3	[1],[2]	8	[1],[2]
Balance	0	[1],[3]	2,227	[1],[3]	0	[1],[3]	2,227	[1],[3]
Commercial Real Estate Portfolio Segment [Member] | Land [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					287	[1],[2]	38,296	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	[1],[3]	3	[1],[3]	0	[1],[3]	3	[1],[3]
Count					2	[1],[2]	23	[1],[2]
Balance	0	[1],[3]	2,081	[1],[3]	0	[1],[3]	2,081	[1],[3]
Commercial Real Estate Portfolio Segment [Member] | Office [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					3,465	[1],[2]	4,795	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	[1],[3]	0	[1],[3]	1	[1],[3]	0	[1],[3]
Count					3	[1],[2]	2	[1],[2]
Balance	1,648	[1],[3]	0	[1],[3]	1,648	[1],[3]	0	[1],[3]
Commercial Real Estate Portfolio Segment [Member] | Industrial [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					1,676	[1],[2]	2,110	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	[1],[3]	2	[1],[3]	1	[1],[3]	2	[1],[3]
Count					2	[1],[2]	3	[1],[2]
Balance	727	[1],[3]	1,786	[1],[3]	727	[1],[3]	1,786	[1],[3]
Commercial Real Estate Portfolio Segment [Member] | Retail Site [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					5,085	[1],[2]	26,460	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	0	[1],[3]	1	[1],[3]	0	[1],[3]	2	[1],[3]
Count					4	[1],[2]	15	[1],[2]
Balance	0	[1],[3]	1,605	[1],[3]	0	[1],[3]	3,840	[1],[3]
Commercial Real Estate Portfolio Segment [Member] | Multi Family [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					1,085	[1],[2]	4,414	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	1	[1],[3]	0	[1],[3]	1	[1],[3]	0	[1],[3]
Count					2	[1],[2]	6	[1],[2]
Balance	705	[1],[3]	0	[1],[3]	705	[1],[3]	0	[1],[3]
Commercial Real Estate Portfolio Segment [Member] | Mixed Use And Other [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					7,230	[1],[2]	11,429	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	3	[1],[3]	3	[1],[3]	3	[1],[3]	6	[1],[3]
Count					11	[1],[2]	25	[1],[2]
Balance	683	[1],[3]	1,158	[1],[3]	683	[1],[3]	3,441	[1],[3]
Commercial Portfolio Segment [Member] | Commercial And Industrial [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans					2,136	[1],[2]	17,876	[1],[2]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	3	[1],[3]	4	[1],[3]	3	[1],[3]	4	[1],[3]
Count					11	[1],[2]	26	[1],[2]
Balance	236	[1],[3]	531	[1],[3]	236	[1],[3]	531	[1],[3]
All Modifications [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	14,468	[1],[4]	20,654	[1],[4]	16,745	[1],[4]	60,337	[1],[4]
Count	12	[1],[4]	19	[1],[4]	26	[1],[4]	50	[1],[4]
All Modifications [Member] | Residential Real Estate And Other [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	401	[1],[4]	29	[1],[4]	778	[1],[4]	1,075	[1],[4]
Count	3	[1],[4]	1	[1],[4]	7	[1],[4]	5	[1],[4]
All Modifications [Member] | Commercial Real Estate Portfolio Segment [Member] | Residential Construction [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	0	[1],[4]	1,651	[1],[4]	0	[1],[4]	1,651	[1],[4]
Count	0	[1],[4]	2	[1],[4]	0	[1],[4]	2	[1],[4]
All Modifications [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Construction Financing Receivable [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	6,120	[1],[4]	0	[1],[4]	6,120	[1],[4]	622	[1],[4]
Count	3	[1],[4]	0	[1],[4]	3	[1],[4]	2	[1],[4]
All Modifications [Member] | Commercial Real Estate Portfolio Segment [Member] | Land [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	0	[1],[4]	3,844	[1],[4]	287	[1],[4]	31,836	[1],[4]
Count	0	[1],[4]	3	[1],[4]	2	[1],[4]	17	[1],[4]
All Modifications [Member] | Commercial Real Estate Portfolio Segment [Member] | Office [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	3,465	[1],[4]	0	[1],[4]	3,465	[1],[4]	0	[1],[4]
Count	3	[1],[4]	0	[1],[4]	3	[1],[4]	0	[1],[4]
All Modifications [Member] | Commercial Real Estate Portfolio Segment [Member] | Industrial [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	949	[1],[4]	0	[1],[4]	949	[1],[4]	0	[1],[4]
Count	1	[1],[4]	0	[1],[4]	1	[1],[4]	0	[1],[4]
All Modifications [Member] | Commercial Real Estate Portfolio Segment [Member] | Retail Site [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	0	[1],[4]	0	[1],[4]	200	[1],[4]	8,633	[1],[4]
Count	0	[1],[4]	0	[1],[4]	1	[1],[4]	5	[1],[4]
All Modifications [Member] | Commercial Real Estate Portfolio Segment [Member] | Multi Family [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	0	[1],[4]	0	[1],[4]	705	[1],[4]	0	[1],[4]
Count	0	[1],[4]	0	[1],[4]	1	[1],[4]	0	[1],[4]
All Modifications [Member] | Commercial Real Estate Portfolio Segment [Member] | Mixed Use And Other [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	3,533	[1],[4]	2,365	[1],[4]	3,533	[1],[4]	3,637	[1],[4]
Count	2	[1],[4]	3	[1],[4]	2	[1],[4]	6	[1],[4]
All Modifications [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial [Member]
Troubled Debt Restructuring, Debtor, Subsequent Periods [Line Items]
Restructured loans	$ 0	[1],[4]	$ 12,765	[1],[4]	$ 708	[1],[4]	$ 12,883	[1],[4]
Count	0	[1],[4]	10	[1],[4]	6	[1],[4]	13	[1],[4]

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

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

[3] TDRs considered to be in payment default are over 30 days past-due subsequent to the restructuring.

[4] 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.