Accounting for Certain Loans Acquired in a Transfer - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Business Acquisition [Line Items]
Total provision charged to operating expense		$ 2,084
Loans Purchased With Evidence Of Credit Deterioration [Member]
Business Acquisition [Line Items]
Total provision charged to operating expense	0	1,400
Allowances for loan losses	$ 0	$ 0