Loans and Loans Held for Sale - Restructured Loans By Segment and Type of Concession (Details)		3 Months Ended			6 Months Ended
		Jun. 30, 2020 USD ($) loan	Jun. 30, 2019 USD ($) loan		Jun. 30, 2020 USD ($) loan	Jun. 30, 2019 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	[1]	11	14		20	25
Pre-Modification Outstanding Recorded Investment	[1],[2]	$ 1,370,000	$ 6,504,000		$ 8,341,000	$ 11,577,000
Post-Modification Outstanding Recorded Investment	[1],[2]	1,304,000	6,427,000		7,853,000	11,248,000
Total  Difference in Recorded Investment	[1]	$ (66,000)	$ (77,000)		$ (488,000)	$ (329,000)
Principal deferral and maturity date extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		0			2
Pre-Modification Outstanding Recorded Investment	[2]	$ 0			$ 4,677,000
Post-Modification Outstanding Recorded Investment	[2]	0			4,278,000
Total  Difference in Recorded Investment		$ 0			$ (399,000)
Maturity date extension and interest rate reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		1	1		1	2
Pre-Modification Outstanding Recorded Investment	[2]	$ 75,000	$ 151,000		$ 75,000	$ 4,902,000
Post-Modification Outstanding Recorded Investment	[2]	75,000	148,000		75,000	4,677,000
Total  Difference in Recorded Investment		$ 0	$ (3,000)		$ 0	$ (225,000)
Payment deferral resulting in payment delay
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans		1			1
Pre-Modification Outstanding Recorded Investment	[2]	$ 93,000			$ 93,000
Post-Modification Outstanding Recorded Investment	[2]	27,000			27,000
Total  Difference in Recorded Investment		$ (66,000)			$ (66,000)
Maturity date extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		2	1		3	1
Pre-Modification Outstanding Recorded Investment	[2]	$ 701,000	$ 1,322,000		$ 2,592,000	$ 1,322,000
Post-Modification Outstanding Recorded Investment	[2]	701,000	1,311,000		2,572,000	1,311,000
Total  Difference in Recorded Investment		$ 0	$ (11,000)		$ (20,000)	$ (11,000)
Consumer bankruptcy
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		5	10	[3]	10	19	[3]
Pre-Modification Outstanding Recorded Investment		$ 351,000	$ 232,000	[2],[3]	$ 727,000	$ 473,000	[2],[3]
Post-Modification Outstanding Recorded Investment		351,000	229,000	[2],[3]	724,000	440,000	[2],[3]
Total  Difference in Recorded Investment		$ 0	$ (3,000)	[3]	$ (3,000)	$ (33,000)	[3]
Interest rate reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan			1			2
Pre-Modification Outstanding Recorded Investment	[2]		$ 109,000			$ 190,000
Post-Modification Outstanding Recorded Investment	[2]		108,000			189,000
Total  Difference in Recorded Investment			$ (1,000)			$ (1,000)
Maturity date extension and payment reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		2			3
Pre-Modification Outstanding Recorded Investment	[2]	$ 150,000			$ 177,000
Post-Modification Outstanding Recorded Investment	[2]	150,000			177,000
Total  Difference in Recorded Investment		$ 0			$ 0
Principal forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan			1			1
Pre-Modification Outstanding Recorded Investment	[2]		$ 4,690,000			$ 4,690,000
Post-Modification Outstanding Recorded Investment	[2]		4,631,000			4,631,000
Total  Difference in Recorded Investment			$ (59,000)			$ (59,000)
Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		0	3		1	3
Pre-Modification Outstanding Recorded Investment	[2]	$ 0	$ 6,163,000		$ 2,210,000	$ 6,163,000
Post-Modification Outstanding Recorded Investment	[2]	0	6,090,000		2,210,000	6,090,000
Total  Difference in Recorded Investment		$ 0	$ (73,000)		$ 0	$ (73,000)
Commercial real estate | Principal deferral and maturity date extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		0			1
Pre-Modification Outstanding Recorded Investment	[2]	$ 0			$ 2,210,000
Post-Modification Outstanding Recorded Investment	[2]	0			2,210,000
Total  Difference in Recorded Investment		$ 0			$ 0
Commercial real estate | Maturity date extension and interest rate reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan			1			1
Pre-Modification Outstanding Recorded Investment	[2]		$ 151,000			$ 151,000
Post-Modification Outstanding Recorded Investment	[2]		148,000			148,000
Total  Difference in Recorded Investment			$ (3,000)			$ (3,000)
Commercial real estate | Maturity date extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan			1			1
Pre-Modification Outstanding Recorded Investment	[2]		$ 1,322,000			$ 1,322,000
Post-Modification Outstanding Recorded Investment	[2]		1,311,000			1,311,000
Total  Difference in Recorded Investment			$ (11,000)			$ (11,000)
Commercial real estate | Principal forgiveness
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan			1			1
Pre-Modification Outstanding Recorded Investment	[2]		$ 4,690,000			$ 4,690,000
Post-Modification Outstanding Recorded Investment	[2]		4,631,000			4,631,000
Total  Difference in Recorded Investment			$ (59,000)			$ (59,000)
Commercial and industrial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		2	0		3	1
Pre-Modification Outstanding Recorded Investment	[2]	$ 168,000	$ 0		$ 2,635,000	$ 4,751,000
Post-Modification Outstanding Recorded Investment	[2]	102,000	0		2,170,000	4,529,000
Total  Difference in Recorded Investment		$ (66,000)	$ 0		$ (465,000)	$ (222,000)
Commercial and industrial | Principal deferral and maturity date extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans		0			1
Pre-Modification Outstanding Recorded Investment	[2]	$ 0			$ 2,467,000
Post-Modification Outstanding Recorded Investment	[2]	0			2,068,000
Total  Difference in Recorded Investment		$ 0			$ (399,000)
Commercial and industrial | Maturity date extension and interest rate reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		1	0		1	1
Pre-Modification Outstanding Recorded Investment	[2]	$ 75,000	$ 0		$ 75,000	$ 4,751,000
Post-Modification Outstanding Recorded Investment	[2]	75,000	0		75,000	4,529,000
Total  Difference in Recorded Investment		$ 0	$ 0		$ 0	$ (222,000)
Commercial and industrial | Payment deferral resulting in payment delay
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans		1			1
Pre-Modification Outstanding Recorded Investment	[2]	$ 93,000			$ 93,000
Post-Modification Outstanding Recorded Investment	[2]	27,000			27,000
Total  Difference in Recorded Investment		$ (66,000)			$ (66,000)
Commercial construction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		2	0		3	0
Pre-Modification Outstanding Recorded Investment	[2]	$ 701,000	$ 0		$ 2,592,000	$ 0
Post-Modification Outstanding Recorded Investment	[2]	701,000	0		2,572,000	0
Total  Difference in Recorded Investment		$ 0	$ 0		$ (20,000)	$ 0
Commercial construction | Maturity date extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		2			3
Pre-Modification Outstanding Recorded Investment	[2]	$ 701,000			$ 2,592,000
Post-Modification Outstanding Recorded Investment	[2]	701,000			2,572,000
Total  Difference in Recorded Investment		$ 0			$ (20,000)
Residential Mortgage
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		3	2		4	3
Pre-Modification Outstanding Recorded Investment	[2]	$ 310,000	$ 116,000		$ 337,000	$ 166,000
Post-Modification Outstanding Recorded Investment	[2]	310,000	115,000		337,000	163,000
Total  Difference in Recorded Investment		$ 0	$ (1,000)		$ 0	$ (3,000)
Residential Mortgage | Consumer bankruptcy
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	[3]	1	2		1	3
Pre-Modification Outstanding Recorded Investment	[2],[3]	$ 160,000	$ 116,000		$ 160,000	$ 166,000
Post-Modification Outstanding Recorded Investment	[2],[3]	160,000	115,000		160,000	163,000
Total  Difference in Recorded Investment	[3]	$ 0	$ (1,000)		$ 0	$ (3,000)
Residential Mortgage | Maturity date extension and payment reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		2			3
Pre-Modification Outstanding Recorded Investment	[2]	$ 150,000			$ 177,000
Post-Modification Outstanding Recorded Investment	[2]	150,000			177,000
Total  Difference in Recorded Investment		$ 0			$ 0
Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan		4	7		9	15
Pre-Modification Outstanding Recorded Investment	[2]	$ 191,000	$ 216,000		$ 567,000	$ 488,000
Post-Modification Outstanding Recorded Investment	[2]	191,000	213,000		564,000	457,000
Total  Difference in Recorded Investment		$ 0	$ (3,000)		$ (3,000)	$ (31,000)
Home equity | Consumer bankruptcy
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	[3]	4	6		9	13
Pre-Modification Outstanding Recorded Investment	[2],[3]	$ 191,000	$ 107,000		$ 567,000	$ 298,000
Post-Modification Outstanding Recorded Investment	[2],[3]	191,000	105,000		564,000	268,000
Total  Difference in Recorded Investment	[3]	$ 0	$ (2,000)		$ (3,000)	$ (30,000)
Home equity | Interest rate reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan			1			2
Pre-Modification Outstanding Recorded Investment	[2]		$ 109,000			$ 190,000
Post-Modification Outstanding Recorded Investment	[2]		108,000			189,000
Total  Difference in Recorded Investment			$ (1,000)			$ (1,000)
Installment and other consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan			2			3
Pre-Modification Outstanding Recorded Investment	[2]		$ 9,000			$ 9,000
Post-Modification Outstanding Recorded Investment	[2]		9,000			9,000
Total  Difference in Recorded Investment			$ 0			$ 0
Installment and other consumer | Consumer bankruptcy
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Loans | loan	[3]		2			3
Pre-Modification Outstanding Recorded Investment	[2],[3]		$ 9,000			$ 9,000
Post-Modification Outstanding Recorded Investment	[2],[3]		9,000			9,000
Total  Difference in Recorded Investment	[3]		$ 0			$ 0

[1] Refer to Note 1, Basis of Presentation for details of reclassification of our portfolio segments related to the adoption of ASU 2016-13 Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instrument.

[2] Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.

[3] Consumer bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed.