Long-Term Debt - Summary of Term Note Issued to Qualified Institutional Buyers (Detail) $ in Thousands	3 Months Ended
Mar. 31, 2026 USD ($)
Secured Debt \| CRT Arrangement Financing [Member]
Debt Instrument [Line Items]
Unpaid principal balance	$ 596,965
Secured Term Notes \| Fannie Mae MSR Financing
Debt Instrument [Line Items]
Unpaid principal balance	725,000
August 28, 2024 [Member] \| Secured Debt \| CRT Arrangement Financing [Member]
Debt Instrument [Line Items]
Notes Issued	158,500
Unpaid principal balance	$ 133,723
Interest rate spread (Annual)	3.10%
Maturity date, Stated	Sep. 27, 2028
April 4, 2024 [Member] \| Secured Debt \| CRT Arrangement Financing [Member]
Debt Instrument [Line Items]
Notes Issued	$ 247,000
Unpaid principal balance	$ 207,556
Interest rate spread (Annual)	3.35%
Maturity date, Stated	Mar. 29, 2027
March 6, 2024 [Member] \| Secured Debt \| CRT Arrangement Financing [Member]
Debt Instrument [Line Items]
Notes Issued	$ 306,000
Unpaid principal balance	$ 255,686
Interest rate spread (Annual)	3.50%
Maturity date, Stated	Mar. 01, 2027
May 25, 2023 [Member] \| Secured Term Notes \| Fannie Mae MSR Financing
Debt Instrument [Line Items]
Unpaid principal balance	$ 370,000
Interest rate spread (Annual)	3.00%
Maturity date, Stated	May 25, 2028
Maturity date, Optional extension	May 25, 2029
June 27, 2024 [Member] \| Secured Term Notes \| Fannie Mae MSR Financing
Debt Instrument [Line Items]
Unpaid principal balance	$ 355,000
Interest rate spread (Annual)	2.75%
Maturity date, Stated	Dec. 27, 2027
Maturity date, Optional extension	Jun. 26, 2028

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