Assets Acquired in FDIC-Assisted Acquisitions - Pro Forma Information of Acquisitions (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Business Combinations [Abstract]
Net interest income and noninterest income	$ 176,262	$ 187,826
Net loss	(10,233)	(17,744)
Net loss available to common shareholders	$ (13,810)	$ (20,985)
Loss per common share available to common shareholders - basic and diluted	$ (0.58)	$ (0.90)
Average number shares outstanding, basic	23,816	23,446
Average number shares outstanding, diluted	23,857	23,538