Loans, Nonaccrual Loans Segregated by Class of Loans and Loan Portfolio Aging Analysis, Segregated by Class (Details) - USD ($)		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		$ 16,563,000	$ 20,971,000
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		40,279,000	53,300,000
Current		2,833,682,000	2,680,524,000
Total Loans		2,873,961,000	2,733,824,000
90+ and Accruing	[1]	12,046,000	17,985,000
Minimum threshold amount of loans requiring performance bond		500,000
30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		9,010,000	8,824,000
60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		6,140,000	8,074,000
90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		$ 25,129,000	36,402,000
Equipment Lease Financing [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Financing percentage requested for underwriting loans		100.00%
Commercial [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Loans		$ 1,498,351,000	1,432,960,000
Commercial [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		3,402,000	4,339,000
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		3,473,000	6,242,000
Current		74,547,000	115,700,000
Total Loans		78,020,000	121,942,000
90+ and Accruing	[1]	30,000	1,863,000
Commercial [Member] | Construction [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		36,000	40,000
Commercial [Member] | Construction [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		6,000	31,000
Commercial [Member] | Construction [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		3,431,000	6,171,000
Commercial [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		5,928,000	6,725,000
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		11,492,000	14,829,000
Current		1,041,427,000	933,797,000
Total Loans		1,052,919,000	948,626,000
90+ and Accruing	[1]	3,757,000	4,682,000
Commercial [Member] | Real Estate [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		2,947,000	2,471,000
Commercial [Member] | Real Estate [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		622,000	1,595,000
Commercial [Member] | Real Estate [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		7,923,000	10,763,000
Commercial [Member] | Equipment Lease Financing [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		199,000	0
Current		8,315,000	10,344,000
Total Loans		8,514,000	10,344,000
90+ and Accruing	[1]	0	0
Commercial [Member] | Equipment Lease Financing [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		199,000	0
Commercial [Member] | Equipment Lease Financing [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		0	0
Commercial [Member] | Equipment Lease Financing [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		0	0
Commercial [Member] | Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		1,485,000	2,423,000
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		2,359,000	5,086,000
Current		356,539,000	346,962,000
Total Loans		358,898,000	352,048,000
90+ and Accruing	[1]	310,000	2,367,000
Commercial [Member] | Other [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		762,000	826,000
Commercial [Member] | Other [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		121,000	55,000
Commercial [Member] | Other [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,476,000	4,205,000
Residential [Member] | Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		249,000	602,000
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		796,000	1,221,000
Current		60,954,000	61,191,000
Total Loans		61,750,000	62,412,000
90+ and Accruing	[1]	55,000	383,000
Residential [Member] | Construction [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		443,000	92,000
Residential [Member] | Construction [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		62,000	144,000
Residential [Member] | Construction [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		291,000	985,000
Residential [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		5,206,000	6,513,000
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		15,923,000	19,225,000
Current		691,951,000	693,240,000
Total Loans		707,874,000	712,465,000
90+ and Accruing	[1]	6,925,000	7,742,000
Residential [Member] | Real Estate [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,128,000	1,005,000
Residential [Member] | Real Estate [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		3,888,000	5,171,000
Residential [Member] | Real Estate [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		10,907,000	13,049,000
Residential [Member] | Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		183,000	369,000
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,255,000	1,679,000
Current		88,195,000	86,656,000
Total Loans		89,450,000	88,335,000
90+ and Accruing	[1]	448,000	422,000
Residential [Member] | Home Equity [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		527,000	779,000
Residential [Member] | Home Equity [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		148,000	197,000
Residential [Member] | Home Equity [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		580,000	703,000
Consumer [Member] | Consumer Direct [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Nonaccrual loans segregated by class of loans		110,000	0
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		1,440,000	1,743,000
Current		124,966,000	120,393,000
Total Loans		126,406,000	122,136,000
90+ and Accruing	[1]	126,000	141,000
Consumer [Member] | Consumer Direct [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		835,000	1,307,000
Consumer [Member] | Consumer Direct [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		479,000	295,000
Consumer [Member] | Consumer Direct [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		126,000	141,000
Consumer [Member] | Consumer Indirect [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		3,342,000	3,275,000
Current		386,788,000	312,241,000
Total Loans		390,130,000	315,516,000
90+ and Accruing	[1]	395,000	385,000
Consumer [Member] | Consumer Indirect [Member] | 30-59 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		2,133,000	2,304,000
Consumer [Member] | Consumer Indirect [Member] | 60-89 Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		814,000	586,000
Consumer [Member] | Consumer Indirect [Member] | 90+ Days Past Due [Member]
Bank's Loan portfolio aging analysis, segregated by class [Abstract]
Total Past Due		$ 395,000	$ 385,000

[1] 90+ and Accruing are also included in 90+ Days Past Due column.