Servicing Rights - Value Assumptions (Details) - Mortgage servicing rights	9 Months Ended	12 Months Ended
Sep. 30, 2021	Dec. 31, 2020
Servicing Assets at Fair Value [Line Items]
Constant prepayment rate (percent)	12.31%	13.05%
Discount rate (percent)	8.00%	7.75%

Discount rate used to estimate the fair value of servicing assets and servicing liabilities.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 50
-Section 50
-Paragraph 2
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=125521744&loc=d3e122596-111746

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- Definition

Estimated rate of prepayments of principal on servicing assets and servicing liabilities.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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