Goodwill and Other Intangible Assets - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Goodwill And Other Intangible Assets [Line Items]
Amortization of Intangible Assets		$ 2,300,000	$ 2,400,000	$ 1,600,000
Goodwill	57,517,000	57,517,000	56,238,000	53,169,000
Goodwill impairment	0	0
Material impairment to identifiable intangibles		0	0	0
Aggregate fair value of mortgage servicing rights	7,200,000	7,200,000	4,200,000
Maximum [Member]
Goodwill And Other Intangible Assets [Line Items]
Range of discount rates used for valuation of mortgage servicing rights		10.00%	10.00%
Minimum [Member]
Goodwill And Other Intangible Assets [Line Items]
Range of discount rates used for valuation of mortgage servicing rights		5.00%	5.00%
John T. Fretz Insurance Agency, Inc. [Member]
Goodwill And Other Intangible Assets [Line Items]
Additional goodwill		1,300,000
Customer related intangibles		1,300,000
Goodwill acquisition date		May 01, 2013
Javers Group [Member]
Goodwill And Other Intangible Assets [Line Items]
Additional goodwill			3,100,000
Customer related intangibles		989,000	989,000
Goodwill acquisition date		May 31, 2012	May 31, 2012
Customer Related Intangibles [Member]
Goodwill And Other Intangible Assets [Line Items]
Impairment on customer related intangibles		$ 83,000	$ 31,000	$ 11,000