Assets Acquired in FDIC-Assisted Acquisitions - Pro Forma Information of Acquisitions (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Business Combinations [Abstract]
Net interest income and noninterest income	$ 176,262
Net loss	(10,233)
Net loss available to common shareholders	$ (13,810)
Loss per common share available to common shareholders - basic and diluted	$ (0.58)
Average number shares outstanding, basic	23,816
Average number shares outstanding, diluted	23,857