Loans and Allowance for Loan Losses - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Accounts, Notes, Loans and Financing Receivable [Line Items]
Deferred loan fee income					$ 89,000,000
Loans modified in TDRs	20,315,000		20,315,000		22,433,000
Unfunded commitments available for funding	200,000		200,000
Loans modified in TDRs during the period	455,000	6,496,000	13,457,000	7,153,000
Forgiveness Of Principal
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in TDRs during the period			2,700,000
Payment Deferrals Granted
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans modified in TDRs during the period		$ 6,500,000	$ 10,800,000	$ 7,200,000