Indemnification Asset - Summary of Activity in Balance of Indemnification Asset (Liability) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
FDIC Indemnification Asset [Roll Forward]
Beginning balance	$ (349)	$ 206
Effect of actual and estimated future covered losses and recoveries	(62)	(468)
Reimbursable (revenue) expenses incurred	(3)	59
Payments (received from) made to FDIC	(19)	(17)
Ending balance	(433)	(220)
Amount of indemnification asset (liability) recorded in other assets	114	(220)
Amount of indemnification asset (liability) recorded in other liabilities	(547)
Ending balance	$ (433)	$ (220)