Loans, Allowance for Credit Losses - Loans, and Credit Quality - Narrative (Details)	6 Months Ended	12 Months Ended
Jun. 30, 2020 USD ($) Loan	Dec. 31, 2019 USD ($) Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Material loans criteria for ALLL adequacy calculation	$ 250,000
Number of loans classified as troubled debt \| Loan	5	5
Troubled debt restructuring current outstanding balance	$ 1,100,000	$ 1,100,000
Pre-modification balance	1,700,000	1,400,000
Financing receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest receivable	$ 9,000,000	$ 7,000,000

Material Loans Criteria For ACL Loans Adequacy Calculation

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+ References

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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Amount, after troubled debt restructuring, of modified financing receivable.

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Amount, before troubled debt restructuring, of financing receivable to be modified.

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.8)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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