Loans and Leases - Major classifications of LHFI (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017 USD ($) loan	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) loan	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of loans | loan	5		5		5
Charge-offs	$ 337	$ 425	$ 1,229	$ 1,128	$ 1,300
Major classifications of loans held for investment [Abstract]
Total LHFI, net of unearned income	594,565	575,818	594,565	575,818	602,009
Proceeds from sales of loans and leases			5,611	2,036
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs	0	7	79	84	84
Major classifications of loans held for investment [Abstract]
Total LHFI, net of unearned income	256,452	253,074	256,452	253,074	261,561
Construction and land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs	0	0	0	0	0
Major classifications of loans held for investment [Abstract]
Total LHFI, net of unearned income	78,389	74,885	78,389	74,885	83,369
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs	0	0	0	108	107
Major classifications of loans held for investment [Abstract]
Total LHFI, net of unearned income	110,861	106,254	110,861	106,254	108,146
Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs	0	0	0	0	0
Major classifications of loans held for investment [Abstract]
Total LHFI, net of unearned income	33,751	23,831	33,751	23,831	23,389
Residential real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs	0	0	8	40	40
Major classifications of loans held for investment [Abstract]
Total LHFI, net of unearned income	55,643	49,061	55,643	49,061	56,899
Leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs	322	310	1,119	757	930
Major classifications of loans held for investment [Abstract]
Total LHFI, net of unearned income	55,270	62,671	55,270	62,671	61,838
Tax certificates
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs	15	108	23	139	139
Major classifications of loans held for investment [Abstract]
Total LHFI, net of unearned income	1,290	3,803	1,290	3,803	3,705
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Charge-offs	0	0	0	0	0
Major classifications of loans held for investment [Abstract]
Total LHFI, net of unearned income	$ 2,909	$ 2,239	$ 2,909	$ 2,239	$ 3,102