Loans (Additions To TDR During The Period) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2012		Jun. 30, 2011		Jun. 30, 2012		Jun. 30, 2011
Accruing Interest [Member]
Financing Receivable, Modifications [Line Items]
Change in recorded investment due to principal paydown at time of modification	$ 150	[1]			$ 950	[1]	$ 400	[1]
Change in recorded investment due to charge- offs as part of the multiple note structuring					5,800	[1]	7,817	[1]
Number of Borrowers	3		19		13		36
Pre-Modification Outstanding Recorded Investment	2,019	[1]	55,424	[1]	56,904	[1]	83,568	[1]
Post-Modification Outstanding Recorded Investment	1,869	[1]	55,424	[1]	50,154	[1]	75,351	[1]
Accruing Interest [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	2		11		6		17
Pre-Modification Outstanding Recorded Investment	1,800	[1]	51,701	[1]	51,084	[1]	57,151	[1]
Post-Modification Outstanding Recorded Investment	1,650	[1]	51,701	[1]	45,134	[1]	57,151	[1]
Accruing Interest [Member] | Commercial Loan [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	2	[2]	8	[2]	5	[2]	13	[2]
Pre-Modification Outstanding Recorded Investment	1,800	[1],[2]	41,230	[1],[2]	33,488	[1],[2]	44,986	[1],[2]
Post-Modification Outstanding Recorded Investment	1,650	[1],[2]	41,230	[1],[2]	33,338	[1],[2]	44,986	[1],[2]
Accruing Interest [Member] | Commercial Loan [Member] | Other Concession [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers			3	[3]			4	[3]
Pre-Modification Outstanding Recorded Investment			10,471	[1],[3]			12,165	[1],[3]
Post-Modification Outstanding Recorded Investment			10,471	[1],[3]			12,165	[1],[3]
Accruing Interest [Member] | Commercial Loan [Member] | Multiple Note Structuring [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers					1
Pre-Modification Outstanding Recorded Investment					17,596	[1]
Post-Modification Outstanding Recorded Investment					11,796	[1]
Accruing Interest [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers					2		13
Pre-Modification Outstanding Recorded Investment					3,313	[1]	25,323	[1]
Post-Modification Outstanding Recorded Investment					2,513	[1]	17,106	[1]
Accruing Interest [Member] | Commercial Real Estate [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	1	[2]	5	[2]	2	[2]	10	[2]
Pre-Modification Outstanding Recorded Investment	219	[1],[2]	3,323	[1],[2]	3,313	[1],[2]	6,496	[1],[2]
Post-Modification Outstanding Recorded Investment	219	[1],[2]	3,323	[1],[2]	2,513	[1],[2]	6,496	[1],[2]
Accruing Interest [Member] | Commercial Real Estate [Member] | Multiple Note Structuring [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers							3
Pre-Modification Outstanding Recorded Investment							18,827	[1]
Post-Modification Outstanding Recorded Investment							10,610	[1]
Accruing Interest [Member] | Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers					4		2
Pre-Modification Outstanding Recorded Investment					2,382	[1]	374	[1]
Post-Modification Outstanding Recorded Investment					2,382	[1]	374	[1]
Accruing Interest [Member] | Residential Real Estate [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers			2	[2]	3	[2]	2	[2]
Pre-Modification Outstanding Recorded Investment			374	[1],[2]	2,182	[1],[2]	374	[1],[2]
Post-Modification Outstanding Recorded Investment			374	[1],[2]	2,182	[1],[2]	374	[1],[2]
Accruing Interest [Member] | Residential Real Estate [Member] | Other Concession [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers					1	[3]
Pre-Modification Outstanding Recorded Investment					200	[1],[3]
Post-Modification Outstanding Recorded Investment					200	[1],[3]
Accruing Interest [Member] | Home Equity Line of Credit [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers			1	[2]	1	[2]	2	[2]
Pre-Modification Outstanding Recorded Investment			26	[1],[2]	125	[1],[2]	203	[1],[2]
Post-Modification Outstanding Recorded Investment			26	[1],[2]	125	[1],[2]	203	[1],[2]
Accruing Interest [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers							2
Pre-Modification Outstanding Recorded Investment							517	[1]
Post-Modification Outstanding Recorded Investment							517	[1]
Accruing Interest [Member] | Consumer Loan [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers							1	[2]
Pre-Modification Outstanding Recorded Investment							265	[1],[2]
Post-Modification Outstanding Recorded Investment							265	[1],[2]
Accruing Interest [Member] | Consumer Loan [Member] | Other Concession [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers							1	[3]
Pre-Modification Outstanding Recorded Investment							252	[1],[3]
Post-Modification Outstanding Recorded Investment							252	[1],[3]
Non Accrual [Member]
Financing Receivable, Modifications [Line Items]
Change in recorded investment due to principal paydown at time of modification	95	[1]			95	[1]	15	[1]
Number of Borrowers	5		8		10		16
Pre-Modification Outstanding Recorded Investment	32,887	[1]	4,403	[1]	36,710	[1]	13,553	[1]
Post-Modification Outstanding Recorded Investment	32,982	[1]	4,403	[1]	36,805	[1]	13,538	[1]
Non Accrual [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	2				3		2
Pre-Modification Outstanding Recorded Investment	15,895	[1]			18,895	[1]	247	[1]
Post-Modification Outstanding Recorded Investment	16,085	[1]			19,085	[1]	247	[1]
Non Accrual [Member] | Commercial Loan [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	1	[2]			1	[2]	1	[2]
Pre-Modification Outstanding Recorded Investment	1,573	[1],[2]			1,573	[1],[2]	119	[1],[2]
Post-Modification Outstanding Recorded Investment	1,573	[1],[2]			1,573	[1],[2]	119	[1],[2]
Non Accrual [Member] | Commercial Loan [Member] | Other Concession [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	1	[3]			2	[3]	1	[3]
Pre-Modification Outstanding Recorded Investment	14,322	[1],[3]			17,322	[1],[3]	128	[1],[3]
Post-Modification Outstanding Recorded Investment	14,512	[1],[3]			17,512	[1],[3]	128	[1],[3]
Non Accrual [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	1		2		5		5
Pre-Modification Outstanding Recorded Investment	16,281	[1]	1,683	[1]	17,104	[1]	10,223	[1]
Post-Modification Outstanding Recorded Investment	16,186	[1]	1,683	[1]	17,009	[1]	10,223	[1]
Non Accrual [Member] | Commercial Real Estate [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers			1	[2]	4	[2]	3	[2]
Pre-Modification Outstanding Recorded Investment			662	[1],[2]	823	[1],[2]	4,015	[1],[2]
Post-Modification Outstanding Recorded Investment			662	[1],[2]	823	[1],[2]	4,015	[1],[2]
Non Accrual [Member] | Commercial Real Estate [Member] | Other Concession [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	1	[3]	1	[3]	1	[3]	2	[3]
Pre-Modification Outstanding Recorded Investment	16,281	[1],[3]	1,021	[1],[3]	16,281	[1],[3]	6,208	[1],[3]
Post-Modification Outstanding Recorded Investment	16,186	[1],[3]	1,021	[1],[3]	16,186	[1],[3]	6,208	[1],[3]
Non Accrual [Member] | Construction Loans [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers			1	[2]			1	[2]
Pre-Modification Outstanding Recorded Investment			179	[1],[2]			179	[1],[2]
Post-Modification Outstanding Recorded Investment			179	[1],[2]			179	[1],[2]
Non Accrual [Member] | Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	1		3		1		4
Pre-Modification Outstanding Recorded Investment	223	[1]	1,904	[1]	223	[1]	2,142	[1]
Post-Modification Outstanding Recorded Investment	223	[1]	1,904	[1]	223	[1]	2,142	[1]
Non Accrual [Member] | Residential Real Estate [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	1	[2]	2	[2]	1	[2]	3	[2]
Pre-Modification Outstanding Recorded Investment	223	[1],[2]	1,208	[1],[2]	223	[1],[2]	1,446	[1],[2]
Post-Modification Outstanding Recorded Investment	223	[1],[2]	1,208	[1],[2]	223	[1],[2]	1,446	[1],[2]
Non Accrual [Member] | Residential Real Estate [Member] | Other Concession [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers			1	[3]			1	[3]
Pre-Modification Outstanding Recorded Investment			696	[1],[3]			696	[1],[3]
Post-Modification Outstanding Recorded Investment			696	[1],[3]			696	[1],[3]
Non Accrual [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	1		2		1		2
Pre-Modification Outstanding Recorded Investment	488	[1]	637	[1]	488	[1]	637	[1]
Post-Modification Outstanding Recorded Investment	488	[1]	637	[1]	488	[1]	637	[1]
Non Accrual [Member] | Home Equity Line of Credit [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers			1	[2]			1	[2]
Pre-Modification Outstanding Recorded Investment			147	[1],[2]			147	[1],[2]
Post-Modification Outstanding Recorded Investment			147	[1],[2]			147	[1],[2]
Non Accrual [Member] | Home Equity Line of Credit [Member] | Other Concession [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers	1	[3]	1	[3]	1	[3]	1	[3]
Pre-Modification Outstanding Recorded Investment	488	[1],[3]	490	[1],[3]	488	[1],[3]	490	[1],[3]
Post-Modification Outstanding Recorded Investment	488	[1],[3]	490	[1],[3]	488	[1],[3]	490	[1],[3]
Non Accrual [Member] | Consumer Loan [Member] | Extension Of Maturity Date [Member]
Financing Receivable, Modifications [Line Items]
Number of Borrowers							2	[2]
Pre-Modification Outstanding Recorded Investment							125	[1],[2]
Post-Modification Outstanding Recorded Investment							$ 110	[1],[2]

[1] Represents amounts as of the date immediately prior to and immediately after the modification is effective.

[2] Extension of maturity date also includes loans renewed at existing rate of interest which is considered a below market rate for that particular loan's risk profile.

[3] Other concessions primarily include interest rate reductions, loan increases, and deferral of principal.