Acquisition and Divestiture Costs (Details)			12 Months Ended
		Oct. 04, 2013 USD ($)	Dec. 31, 2015 USD ($) branch	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Oct. 16, 2015	Oct. 16, 2015 branch	Oct. 26, 2012
Business Acquisition [Line Items]
Payments of Stock Issuance Costs			$ 612,000	$ 0	$ 0
Salaries and employee benefits			37,220,000	32,669,000	32,609,000
Gain on branch divestiture			$ 0	0	2,742,000
Number of Branches | branch			64
Number of companies in integration			2
Acquisition and divestiture costs			$ 10,415,000	0	374,000
Furniture, equipment and data processing			8,057,000	7,316,000	7,051,000
Net occupancy			5,695,000	5,055,000	5,449,000
Consulting and professional fees			2,625,000	2,368,000	2,337,000
Other expenses			11,146,000	9,570,000	10,374,000
SBM Financial, Inc. [Member]
Business Acquisition [Line Items]
Salaries and employee benefits	[1]		3,240,000
Number of Branches						4	64
Non-compete agreement costs			400,000
Acquisition and divestiture costs			10,400,000
Furniture, equipment and data processing			1,531,000
Net occupancy			1,237,000
Consulting and professional fees	[2]		2,453,000
Other expenses	[3]		$ 1,954,000
Branch Acquisition [Member]
Business Acquisition [Line Items]
Number of full-service branches acquired								14
Branches To Be Disposed Of [Member]
Business Acquisition [Line Items]
Salaries and employee benefits	[1]			0	0
Deposits and Borrowings Divested		$ 85,900,000
Loans Divested		46,000,000
Real Estate and Equipment Divested		$ 602,000
Premium on Deposits Sold		3.50%
Gain on branch divestiture		$ 2,700,000
Number of Branches		0
Acquisition and divestiture costs				400,000
Furniture, equipment and data processing				0	78,000
Net occupancy				0	3,000
Consulting and professional fees	[2]			0	134,000
Other expenses	[3]			$ 0	$ 159,000

[1] (1) Includes the costs associated with pre-existing change-in-control agreements in place at the time of the SBM acquisition and employee termination costs, including severance.

[2] (2)Includes the cost of a negotiated non-compete arrangement entered into in connection with the SBM acquisition of $400,000 in 2015.

[3] (3) Other expenses include marketing and insurance costs, certain contract termination costs, various printing and mailing costs associated with various customer communications, and travel-related costs associated with the integration of the two companies in 2015.