Loans and Allowance for Loan Losses - Impaired Loans Segregated by Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	$ 43,130	$ 49,972
Recorded Investment with Allowance	38,326	45,173
Related Allowance	3,478	4,492
Average Recorded Investment	39,262	42,519
Non-residential real estate owner occupied [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	877	596
Recorded Investment with Allowance	752	535
Related Allowance	28	24
Average Recorded Investment	881	1,557
Non-residential real estate other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	24,964	27,502
Recorded Investment with Allowance	23,351	26,147
Related Allowance	2,161	2,187
Average Recorded Investment	23,816	21,726
Residential real estate primary mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,253	1,297
Recorded Investment with Allowance	1,025	1,084
Related Allowance	58	43
Average Recorded Investment	1,170	1,123
Residential real estate all other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	2,214	4,172
Recorded Investment with Allowance	1,803	3,829
Related Allowance	361	1,285
Average Recorded Investment	1,857	4,062
Non-consumer non-real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,801	1,949
Recorded Investment with Allowance	1,459	1,539
Related Allowance	388	439
Average Recorded Investment	1,553	1,641
Consumer non-real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	628	419
Recorded Investment with Allowance	611	398
Related Allowance	139	87
Average Recorded Investment	455	357
Other loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	1,545	2,957
Recorded Investment with Allowance	1,464	2,561
Related Allowance	219	344
Average Recorded Investment	1,602	2,323
Acquired loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unpaid Principal Balance	9,848	11,080
Recorded Investment with Allowance	7,861	9,080
Related Allowance	124	83
Average Recorded Investment	$ 7,928	$ 9,730