Borrowings - Additional Information (Detail) (USD $)	12 Months Ended		0 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	May 31, 2013 Interest Rate Swap [Member]	Dec. 31, 2013 Trust Preferred Securities [Member]	Dec. 31, 2013 Trust Preferred Securities [Member] London Interbank Borrowing Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 484,100,000
Outstanding borrowings with FHLB	0	0
Outstanding short term letters of credit	35,000,000	32,000,000
Aggregate principal balance of capital securities redeemed				20,000,000
Description of interest rate					(LIBOR) plus 3.05% per annum
Floating rate on loan notes issued					3.05%
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
Amount of maintained federal fund lines of credit with correspondent banks	82,000,000	82,000,000
Amount of federal fund lines of credit with correspondent banks	0	0
Amount of federal fund line of credit with Federal Reserve Bank of Philadelphia	$ 0	$ 0