Indemnification Asset/Liability - Summary of Activity in Balance of Indemnification Asset (Liability) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
FDIC Indemnification Asset [Roll Forward]
Beginning balance	$ (466)	$ (37)	$ (349)	$ 206
Effect of actual covered losses and change in estimated future covered losses	(15)	(5)	(59)	(513)
Change in estimated true up liability	(13)	(9)	(57)	(66)
Reimbursable expenses (revenue), net	3	8		81
Payments made (received)	(1)	30	(27)	279
Ending balance	(492)	(13)	(492)	(13)
Amount of indemnification asset (liability) recorded in other assets			92	(13)
Amount of indemnification liability recorded in other liabilities			(584)
Ending balance	$ (466)	$ (37)	$ (492)	$ (13)