Allowance for Loan Losses - Allowance for Loan Losses and the Recorded Investment in Loans by Portfolio Segment (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012
Financing Receivable, Allowance for Credit Losses [Line Items]
Total ending allowance balance	$ 16,102	$ 15,992	$ 19,565	$ 18,270
Total ending loans balance	7,335		10,078
Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment	1,290	1,312
Allowance For Loan Losses, Collectively evaluated for impairment	14,445	14,291
Loans acquired with deteriorated credit quality	(367)	(389)
Total ending allowance balance	16,102	15,992
Commercial [Member] | Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment	1,290	1,312
Allowance For Loan Losses, Collectively evaluated for impairment	5,580	4,963
Loans acquired with deteriorated credit quality	(367)	(389)
Total ending allowance balance	7,237	6,664
Real Estate [Member] | Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment
Allowance For Loan Losses, Collectively evaluated for impairment	2,812	3,462
Loans acquired with deteriorated credit quality
Total ending allowance balance	2,812	3,462
Consumer [Member] | Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment
Allowance For Loan Losses, Collectively evaluated for impairment	4,388	4,228
Loans acquired with deteriorated credit quality
Total ending allowance balance	4,388	4,228
Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment	7,335	7,448
Loans: Collectively evaluated for impairment	1,096,208	1,054,157
Loans acquired with deteriorated credit quality	492	10,409
Total ending loans balance	1,104,035	1,072,014
Loans [Member] | Commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment	7,335	7,448
Loans: Collectively evaluated for impairment	522,054	489,547
Loans acquired with deteriorated credit quality	492	9,355
Total ending loans balance	529,881	506,350
Loans [Member] | Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment
Loans: Collectively evaluated for impairment	190,486	186,526
Loans acquired with deteriorated credit quality		24
Total ending loans balance	190,486	186,550
Loans [Member] | Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment
Loans: Collectively evaluated for impairment	281,042	279,448
Loans acquired with deteriorated credit quality		1,030
Total ending loans balance	281,042	280,478
Mortgage Warehousing [Member] | Allowance for Loan Losses [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance For Loan Losses, Individually evaluated for impairment
Allowance For Loan Losses, Collectively evaluated for impairment	1,665	1,638
Loans acquired with deteriorated credit quality
Total ending allowance balance	1,665	1,638
Mortgage Warehousing [Member] | Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans: Individually evaluated for impairment
Loans: Collectively evaluated for impairment	102,626	98,636
Loans acquired with deteriorated credit quality
Total ending loans balance	$ 102,626	$ 98,636