Mortgage Banking Activities, Mortgage Servicing Rights (Details)	3 Months Ended	6 Months Ended	12 Months Ended
Jun. 30, 2025 USD ($)	Mar. 31, 2025 USD ($)	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Summary of Mortgage Servicing Rights [Abstract]
Number of residential mortgage loans serviced for others	126,767			126,767		125,728
Outstanding principal balance of residential mortgage loans serviced for others	$ 22,542,310,000			$ 22,542,310,000		$ 22,269,513,000
Weighted average interest rate	3.79%			3.79%		3.73%
Remaining term (in months)		276 months		274 months
Servicing Asset at Fair Value, Amount [Roll Forward]
Beginning balance	$ 342,111,000	$ 338,145,000	$ 319,330,000	$ 338,145,000	$ 293,884,000	$ 293,884,000
Additions	3,063,000		4,454,000	5,572,000	6,970,000
Acquisitions	0		14,021,000	14,615,000	31,421,000
Changes due to principal payments	(5,511,000)		(8,012,000)	(11,429,000)	(13,459,000)
Change in fair value due to market assumption changes	(5,019,000)		3,453,000	(12,259,000)	14,430,000
Ending balance	$ 334,644,000	$ 342,111,000	$ 333,246,000	$ 334,644,000	$ 333,246,000	$ 338,145,000
Servicing Assets at Fair Value, Assumptions Used to Estimate Fair Value [Abstract]
Discount rate - risk-free rate plus a market premium (in hundredths)				9.24%		9.60%
Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed				7.02%		7.09%
Loan servicing costs - annually per loan based upon loan type, performing, minimum (in dollars per loan)				$ 73		$ 73
Loan servicing costs - annually per loan based upon loan type, performing, maximum (in dollars per loan)				94		94
Loan servicing costs - annually per loan based upon loan type, delinquent, minimum (in dollars per loan)				150		150
Loan servicing costs - annually per loan based upon loan type, delinquent, maximum (in dollars per loan)				500		500
Loan servicing costs - annually per loan based upon loan type, foreclosure, minimum (in dollars per loan)				875		875
Loan servicing costs - annually per loan based upon loan type, foreclosure, maximum (in dollars per loan)				$ 6,000		$ 6,000
Escrow earnings rate - indexed to rates paid on deposit accounts with comparable average life (in hundredths)				3.63%		4.44%
Primary secondary mortgage rate spread	128			128		115
Delinquency rate				2.24%		2.19%

The decrease in fair value as a result of loan runoff.

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- Definition

Mortgage rate spread between the primary and secondary market.

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No definition available.

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Indicates the number of mortgage loans being serviced.

+ References

No definition available.

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Dollar amount of principal outstanding on mortgage loans being serviced.

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Represents the weighted average remaining term of mortgage loans being serviced fro others.

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No definition available.

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- Definition

The value of new servicing assets, subsequently measured at fair value, acquired during the current period through purchases of financial assets.

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No definition available.

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- Definition

Servicing Assets at Fair Value Assumptions Used to Estimate Fair Value Delinquent Loan Service Cost Minimum

+ References

No definition available.

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Servicing Assets At Fair Value Assumptions Used to Estimate Fair Value Delinquent

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No definition available.

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- Definition

The escrow earning rate used to estimate the fair value of servicing assets, based on rates paid on deposit accounts.

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No definition available.

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- Definition

Servicing Assets At Fair Value Assumptions Used to Estimate Fair Value Foreclosure Loan Service Cost Maximum

+ References

No definition available.

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Servicing Assets at Fair Value Assumptions Used to Estimate Fair Value Foreclosure Loan Service Cost Minimum

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No definition available.

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- Definition

The maximum cost to service a performing loan for the period used as a variable in estimating fair value.

+ References

No definition available.

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- Definition

The minimum cost to service a performing loan for the period used as a variable in estimating fair value.

+ References

No definition available.

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- Definition

Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Delinquency Rate

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No definition available.

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- Definition

-- None. No documentation exists for this element. --

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- Definition

Represents the weighted average interest rate of loans servicedf for others as of the balance sheet date.

+ References

No definition available.

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- Definition

Amount of increase (decrease) in fair value from changes in the assumptions or model used to calculate the fair value of a contract to service financial assets under which the benefits of servicing are expected to more than adequately compensate the servicer.

+ References

No definition available.

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- Definition

The value of new servicing assets, subsequently measured at fair value, acquired or created during the current period through purchases or from transfers of financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-3

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- Definition

Fair value of an asset representing net future revenue from contractually specified servicing fees, late charges, and other ancillary revenues, in excess of future costs related to servicing arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
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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.

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- Definition

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

+ References

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- Definition

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

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