Subsequent Events - Additional Information (Detail) (USD $)	12 Months Ended	0 Months Ended
	Dec. 31, 2014 Branches	Jan. 29, 2015	Jan. 28, 2015
Merchants and Southern Banks of Florida [Member]
Schedule of Reverse Stock Split [Line Items]
Assets acquired through merger	$ 473,000,000
Loans acquired	214,000,000
Deposits acquired	336,000,000
Number of branches	13
Subsequent Event [Member] | Private Placement [Member]
Schedule of Reverse Stock Split [Line Items]
Common stock shares		5,320,000
Common stock price		$ 22.50
Net proceeds from issuance of common stock		114,500,000
Subsequent Event [Member] | Merchants and Southern Banks of Florida [Member]
Schedule of Reverse Stock Split [Line Items]
Purchase price			50,000,000
Subsequent Event [Member] | Bank of America [Member]
Schedule of Reverse Stock Split [Line Items]
Deposits acquired			$ 812,000,000
Number of branches			18
Deposit premium			3.00%