Loans (Troubled Debt Restructured Loans Outstanding) (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Accruing Interest [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	$ 97,690	$ 100,909
Accruing Interest [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	82,218	42,569
Accruing Interest [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	12,977	41,348
Accruing Interest [Member] | Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	874	3,238
Accruing Interest [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	1,621
Accruing Interest [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding		13,754
Non Accrual [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	92,004	75,404
Non Accrual [Member] | Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	47,839	28,409
Non Accrual [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	34,764	32,722
Non Accrual [Member] | Construction Loans [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding		960
Non Accrual [Member] | Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	1,860	3,592
Non Accrual [Member] | Home Equity Line of Credit [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	2,489	2,082
Non Accrual [Member] | Consumer Loan [Member]
Financing Receivable, Modifications [Line Items]
Troubled debt restructured loans outstanding	$ 5,052	$ 7,639