Loans - Average Recorded Investment and Interest Income Recognized on Impaired Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	$ 174,782	$ 220,288	$ 183,617	$ 218,806
Interest Income Recognized	1,799	1,711	3,230	3,102
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	112,184	133,998	114,669	133,282
Interest Income Recognized	1,078	936	1,867	1,756
Consumer Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	1,427	1,174	1,253	1,194
Interest Income Recognized	29	14	42	26
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	34,698	56,017	40,707	55,644
Interest Income Recognized	290	412	659	788
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	93,123	114,066	95,321	113,735
Interest Income Recognized	924	866	1,569	1,617
Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	19,061	19,932	19,348	19,547
Interest Income Recognized	154	70	298	139
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	26,473	29,099	26,988	28,686
Interest Income Recognized	402	349	662	532
Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Average Recorded Investment	1,427	1,174	1,253	1,194
Interest Income Recognized	$ 29	$ 14	$ 42	$ 26