Fair Value Measurements - Changes in Level 3 (Details) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019
US States and Political Subdivisions Debt Securities [Member]
Changes in Level 3
Beginning balance	$ 5,419	$ 8,165
Total gains or losses
Included in earnings (or changes in net assets)		(25)
Included in other comprehensive income	(216)	898
Purchases, issuances, sales, and settlements
Purchases	12,900	17,643
Settlements	(13,297)	(20,808)
Ending balance	4,790	5,873
Changes in Level 3 (liabilities)
Included in earnings (or changes in net assets)	(16)
Mortgage Servicing Rights [Member]
Changes in Level 3
Beginning balance	5,935	7,357
Total gains or losses
Included in earnings (or changes in net assets)		(2,384)
Purchases, issuances, sales, and settlements
Issuances	1,813	906
Settlements	(275)	(518)
Ending balance	5,010	$ 5,361
Changes in Level 3 (liabilities)
Included in earnings (or changes in net assets)	$ (2,463)

No definition available.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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-Publisher FASB
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-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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