Other Borrowings - Summary of Other Borrowings (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Total other borrowings	$ 43,851	$ 78,881	$ 59,677
Daily Rate Credit From Federal Home Loan Bank [Member]
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Debt instrument advances		35,000	25,000
Revolving Credit Facility 1 [Member]
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Debt instrument advances	24,000	24,000
Revolving Credit Facility [Member]
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Debt instrument advances			10,000
Correspondent Bank Advances [Member]
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Advance from correspondent bank with a fixed interest rate of 4.50%, due November 27, 2017, secured by subsidiary bank loan receivable	4,851	4,881	4,963
Subordinated Debt One [Member]
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Subordinated debt issued			5,000
Subordinated Debt Two [Member]
Federal Home Loan Bank Borrowings By Year Of Maturity And Applicable Interest Rate [Line Items]
Subordinated debt issued	$ 15,000	$ 15,000	$ 14,714