Earnings Per Share - Computation of Earnings Per Share (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net income per consolidated statements of income	$ 2,900	$ 1,717	$ 47,398	$ 7,788
Net income allocated to participating securities	(19)	(4)	(247)	(22)
Amortization of discount on preferred stock			0	(6,751)
Net income allocated to common stock	2,881	1,713	47,151	1,015
Distributed earnings allocated to common stock	500	0	500	0
Undistributed earnings allocated to common stock	2,381	1,713	46,651	1,015
Weighted average common shares outstanding, including shares considered participating securities	50,031	50,219	50,329	42,455
Less: Average participating securities	(333)	(109)	(263)	(118)
Weighted average shares	49,698	50,110	50,066	42,337
Basic earnings per common share	$ 0.06	$ 0.03	$ 0.94	$ 0.02
Net income allocated to common stock	$ 2,881	$ 1,713	$ 47,151	$ 1,015
Weighted average common shares outstanding for basic earnings per common share	49,698	50,110	50,066	42,337
Add: Dilutive effects of assumed exercises of stock options	260	272	234	275
Weighted average shares and dilutive potential common shares	49,958	50,382	50,300	42,612
Diluted earnings per common share	$ 0.06	$ 0.03	$ 0.94	$ 0.02