Accounting for Certain Loans Acquired in a Transfer - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Business Acquisition [Line Items]
Total provision charged to operating expense	$ 339	$ 729	$ 339	$ 2,813
Loans Purchased With Evidence Of Credit Deterioration [Member]
Business Acquisition [Line Items]
Total provision charged to operating expense	339	100	339	1,500
Allowances for loan losses	$ 0	$ 0	$ 0	$ 0