Mortgage Servicing Rights - Summary of Net Loan Servicing Fees Relating to MSRs (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Transfers and Servicing [Abstract]
Contractually-specified servicing fees	$ 140,423	$ 151,395	$ 432,418	$ 456,705
Late charges	1,066	1,092	3,200	3,155
Other	2,859	3,336	9,168	10,317
Mortgage loan other servicing fees	3,925	4,428	12,368	13,472
Net mortgage loan servicing fees	144,348	155,823	444,786	470,177
Average UPB of underlying loans	$ 200,144,607	$ 220,178,747	$ 207,765,234	$ 222,854,243

Average mortgage servicing rights unpaid principal balance.

No definition available.

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- Definition

Mortgage loan other servicing fees.

+ References

No definition available.

+ Details

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- Definition

All amounts that are due to the servicer of a financial asset, excluding contractually specified servicing fees and late fees.

+ References

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

+ Details

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- Definition

All amounts that, per contract, are due to the servicer in exchange for servicing the financial asset and would no longer be received by a servicer if the beneficial owners of the serviced assets (or their trustees or agents) were to exercise their actual or potential authority under the contract to shift the servicing to another servicer. Depending on the servicing contract, those fees may include some or all of the difference between the interest rate collected on the asset being serviced and the rate to be paid to the beneficial owners of the asset.

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+ Details

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- Definition

Amount of contractually specified servicing fee, late fee, and ancillary fee recognized as income for servicing asset and servicing liability.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 860
-SubTopic 50
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481229/860-50-50-2

+ Details

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- Definition

All amounts that are due to the servicer of a financial asset as a result of the debt holder not meeting the monthly payment terms.

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+ Details

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- References

No definition available.

+ Details

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