Loans and Allowance for Loan Losses - Allowance (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Changes in the allowance for loan losses
Beginning balance, excluding PCI loans acquired	$ 11,161		$ 11,775
Balance at beginning of period		$ 11,242	11,775	$ 10,939
Charge-offs	(23)	(676)	(1,779)	(676)
Recoveries	8	2	12	5
Provision	6,423	600	7,561	900
Ending balance, excluding PCI loans acquired	17,569		17,569
Balance at end of period	17,742	11,168	17,742	11,168
Individually evaluated for impairment	1,547	534	1,547	534
Collectively evaluated for impairment	16,022	10,634	16,022	10,634
Purchased credit impaired loans
Changes in the allowance for loan losses
Balance at beginning of period	0		0
Charge-offs	0		0
Recoveries	0		0
Provision	173		173
Balance at end of period	173		173
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	173		173
Commercial and Non-Residential Real Estate
Changes in the allowance for loan losses
Beginning balance, excluding PCI loans acquired	9,597		10,098
Balance at beginning of period		8,864		8,605
Charge-offs	0	(666)	(1,756)	(666)
Recoveries	6	1	6	1
Provision	5,798	772	7,053	1,031
Ending balance, excluding PCI loans acquired	15,401		15,401
Balance at end of period		8,971		8,971
Individually evaluated for impairment	1,547	534	1,547	534
Collectively evaluated for impairment	13,854	8,437	13,854	8,437
Commercial and Non-Residential Real Estate | Purchased credit impaired loans
Changes in the allowance for loan losses
Balance at beginning of period	0		0
Charge-offs	0		0
Recoveries	0		0
Provision	121		121
Balance at end of period	121		121
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	121		121
Residential Real Estate
Changes in the allowance for loan losses
Beginning balance, excluding PCI loans acquired	1,272		1,272
Balance at beginning of period		1,417		1,405
Charge-offs	0	0	0	0
Recoveries	0	0	0	1
Provision	574	(188)	574	(177)
Ending balance, excluding PCI loans acquired	1,846		1,846
Balance at end of period		1,229		1,229
Individually evaluated for impairment	0	0	0	0
Collectively evaluated for impairment	1,846	1,229	1,846	1,229
Residential Real Estate | Purchased credit impaired loans
Changes in the allowance for loan losses
Balance at beginning of period	0		0
Charge-offs	0		0
Recoveries	0		0
Provision	52		52
Balance at end of period	52		52
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	52		52
Home Equity
Changes in the allowance for loan losses
Beginning balance, excluding PCI loans acquired	236		327
Balance at beginning of period		704		684
Charge-offs	(23)	0	(23)	0
Recoveries	2	1	4	2
Provision	49	7	(44)	26
Ending balance, excluding PCI loans acquired	264		264
Balance at end of period		712		712
Individually evaluated for impairment	0	0	0	0
Collectively evaluated for impairment	264	712	264	712
Home Equity | Purchased credit impaired loans
Changes in the allowance for loan losses
Balance at beginning of period	0		0
Charge-offs	0		0
Recoveries	0		0
Provision	0		0
Balance at end of period	0		0
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	0		0
Consumer
Changes in the allowance for loan losses
Beginning balance, excluding PCI loans acquired	56		78
Balance at beginning of period		257		245
Charge-offs	0	(10)	0	(10)
Recoveries	0	0	2	1
Provision	2	9	(22)	20
Ending balance, excluding PCI loans acquired	58		58
Balance at end of period		256		256
Individually evaluated for impairment	0	0	0	0
Collectively evaluated for impairment	58	$ 256	58	$ 256
Consumer | Purchased credit impaired loans
Changes in the allowance for loan losses
Balance at beginning of period	0		0
Charge-offs	0		0
Recoveries	0		0
Provision	0		0
Balance at end of period	0		0
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	$ 0		$ 0