Loans and Allowance for Loan Losses - Additional Information (Detail) (USD $)	3 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2014	Jun. 30, 2014	May 31, 2014	Dec. 31, 2013
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Expense related to the settlement of the assessment with the FDIC	$ 10,300,000
Outstanding claims due from the FDIC, net of settlement			25,000,000
Interest that would have been recorded on non - accrual loans		1,900,000
Interest recovered on non - accrual loans		1,100,000
Non-accrual loans	89,901,000	89,901,000		99,657,000
Troubled debt restructuring		19,400,000		24,900,000
Minimum bank portfolio loan need to be reviewed		1,000,000
Performing [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Period for which payments of principal and interest are past due		Less than 90 days
Troubled Debt Restructurings [Member]
Non Accrual Loans Segregated By Class Of Loans [Line Items]
Non-accrual loans	$ 7,700,000	$ 7,700,000