Loans and Allowance for Loan Losses - Summary of Amounts Included in Nonaccrual Loans Segregated by Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	$ 17,753	$ 14,390	$ 20,933
Non-residential real estate owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	448		382
Non-residential real estate other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	5,779		9,284
Residential real estate permanent mortgage [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	689		619
Residential real estate all other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	958		3,716
Non-consumer non-real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	1,287		1,449
Consumer non-real estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	165		187
Other loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	1,198		3,052
Acquired loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans, Total	$ 7,229		$ 2,244