Fair Value - Additional Information (Detail) (USD $)	9 Months Ended
	Sep. 30, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Range of capitalization rates utilized to determine fair value	9.00%
Transfers between level 1 and level 2	$ 0
Transfers out consisted of charge-offs	1,200,000
Loans classified as level 3 transfers out	0
Loans classified as level 3 migrating to OREO	1,300,000
Recorded sales	0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans classified as level 3 transfers in	2,200,000
Other real estate owned and other reductions	3,400,000
Valuation write-downs	500,000
Other real estate revenue	4,700,000
Other real estate owned and other reductions classified as level 3 transfers out	5,200,000
Other Real Estate Owned [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Loans classified as level 3 transfers in	$ 1,300,000