Trust Preferred Securities - Additional Information (Detail) (USD $)	9 Months Ended	1 Months Ended	9 Months Ended
	Sep. 30, 2013	May 31, 2013 Interest Rate Swap [Member]	Sep. 30, 2013 Subsequent Event [Member]	Sep. 30, 2013 London Interbank Borrowing Rate (LIBOR) [Member]	Sep. 30, 2013 Trust Preferred Securities [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Aggregate principal balance of capital securities redeemed					$ 20,000,000
Description of interest rate				(LIBOR) plus 3.05% per annum
Maturity date	Oct. 07, 2033
Liquidation amount of trust preferred security	$ 1,000
Redemption date	Jul. 07, 2013
Redemption in securities	619,000
Settlement date	Jul. 08, 2013
Loss on Trust Preferred Securities hedge	(1,866,000)	(1,900,000)
Interest rate swap maturity date	Jan. 07, 2019
Expected amount of savings in interest expense in current fiscal year			600,000
Expected amount of savings in interest expense annually through maturity date			$ 1,100,000