Loans and Leases - Aging Analysis of Past Due Payments for Each Loan Portfolio Segment (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Current	$ 597,956,000		$ 597,956,000		$ 594,247,000
Total	605,693,000	$ 547,087,000	605,693,000	$ 547,087,000	602,009,000
Interest income lost on non-accrual loans	108,000	157,000	226,000	315,000
Financing Receivables, 30 to 59 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Total	813,000		813,000		1,742,000
Financing Receivables, 60 to 89 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Total	2,510,000		2,510,000		978,000
Financing Receivables, Equal to Greater than 90 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Total	4,414,000		4,414,000		5,042,000
Commercial real estate
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Current	256,557,000		256,557,000		260,168,000
Total	258,662,000	239,776,000	258,662,000	239,776,000	261,561,000
Commercial real estate | Financing Receivables, 30 to 59 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	149,000		149,000		0
Commercial real estate | Financing Receivables, 60 to 89 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	1,165,000		1,165,000		507,000
Commercial real estate | Financing Receivables, Equal to Greater than 90 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	791,000		791,000		886,000
Construction and land development
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Current	84,782,000		84,782,000		83,225,000
Total	84,910,000	65,385,000	84,910,000	65,385,000	83,369,000
Construction and land development | Financing Receivables, 30 to 59 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	0		0		0
Construction and land development | Financing Receivables, 60 to 89 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	0		0		0
Construction and land development | Financing Receivables, Equal to Greater than 90 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	128,000		128,000		144,000
Commercial and industrial
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Current	115,249,000		115,249,000		107,190,000
Total	116,200,000	97,270,000	116,200,000	97,270,000	108,146,000
Commercial and industrial | Financing Receivables, 30 to 59 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	149,000		149,000		416,000
Commercial and industrial | Financing Receivables, 60 to 89 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	44,000		44,000		367,000
Commercial and industrial | Financing Receivables, Equal to Greater than 90 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	758,000		758,000		173,000
Multi-family
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Current	29,030,000		29,030,000		23,389,000
Total	29,030,000	21,010,000	29,030,000	21,010,000	23,389,000
Multi-family | Financing Receivables, 30 to 59 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	0		0		0
Multi-family | Financing Receivables, 60 to 89 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	0		0		0
Multi-family | Financing Receivables, Equal to Greater than 90 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	0		0		0
Residential real estate
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Current	54,615,000		54,615,000		55,566,000
Total	56,363,000	50,104,000	56,363,000	50,104,000	56,899,000
Residential real estate | Financing Receivables, 30 to 59 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	186,000		186,000		978,000
Residential real estate | Financing Receivables, 60 to 89 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	1,037,000		1,037,000		0
Residential real estate | Financing Receivables, Equal to Greater than 90 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	525,000		525,000		355,000
Leases
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Current	53,955,000		53,955,000		59,809,000
Total	56,258,000	66,898,000	56,258,000	66,898,000	61,838,000
Leases | Financing Receivables, 30 to 59 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	329,000		329,000		348,000
Leases | Financing Receivables, 60 to 89 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	264,000		264,000		104,000
Leases | Financing Receivables, Equal to Greater than 90 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	1,710,000		1,710,000		1,577,000
Tax certificates
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Current	876,000		876,000		1,798,000
Total	1,378,000	4,390,000	1,378,000	4,390,000	3,705,000
Tax certificates | Financing Receivables, 30 to 59 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	0		0		0
Tax certificates | Financing Receivables, 60 to 89 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	0		0		0
Tax certificates | Financing Receivables, Equal to Greater than 90 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	502,000		502,000		1,907,000
Consumer
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Current	2,892,000		2,892,000		3,102,000
Total	2,892,000	$ 2,254,000	2,892,000	$ 2,254,000	3,102,000
Consumer | Financing Receivables, 30 to 59 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	0		0		0
Consumer | Financing Receivables, 60 to 89 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	0		0		0
Consumer | Financing Receivables, Equal to Greater than 90 Days Past Due
Aging analysis of past due payments for each loan portfolio segment [Abstract]
Financing Receivable, Recorded Investment, Past Due	$ 0		$ 0		$ 0