Fair Value - Summary of Changes in Items Measured Using Level 3 Inputs on Recurring Basis (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025
Assets:
Amounts received pursuant to sales of loans	$ 16,926	$ 45,744	$ 88,188	$ 136,783
Interest Rate Lock Commitments with PFSI [Member]
Assets:
Beginning balance			2,348
Changes in fair value included in income arising from:
Ending balance	(16,086)		(16,086)
Recurring [Member]
Assets:
Beginning balance	3,676,258	3,854,330	3,751,498	3,989,252
Purchases and issuances	3,354	12,228	26,476	23,511
Repayments and sales	(219,565)	(20,570)	(259,779)	(59,418)
Accrual of unearned discounts	1,835	2,161	5,645	6,611
Amounts received pursuant to sales of loans	16,926	45,744	88,188	136,783
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	126,455	(92,575)	1,018	(281,781)
Total	126,455	(92,575)	1,018	(281,781)
Loans to REO	(163)		(163)
Interest rate lock commitments to loans held for sale	(2,929)	(25,819)	(13,114)	(39,850)
Mortgage servicing rights relating to delinquent loans to Agency		284	2,402	675
Ending balance	3,602,171	3,775,783	3,602,171	3,775,783
Changes in fair value recognized during the quarter/period relating to assets	118,284	(110,880)	(47,060)	(337,343)
Recurring [Member] \| Credit Risk Transfer Strips [Member]
Assets:
Beginning balance	(5,428)	(10,479)	(5,999)	(4,060)
Purchases and issuances	0	0	(0)	0
Repayments and sales	(7,610)	(9,651)	(24,919)	(29,496)
Accrual of unearned discounts	0	0	0	0
Amounts received pursuant to sales of loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	7,807	10,800	25,687	24,226
Total	7,807	10,800	25,687	24,226
Loans to REO	0		0
Interest rate lock commitments to loans held for sale	0	0	0	0
Mortgage servicing rights relating to delinquent loans to Agency		0	0	0
Ending balance	(5,231)	(9,330)	(5,231)	(9,330)
Changes in fair value recognized during the quarter/period relating to assets	224	1,177	905	(5,124)
Recurring [Member] \| Credit Risk Transfer Derivatives [Member]
Assets:
Beginning balance	30,301	31,147	32,659	29,377
Purchases and issuances	0	0	0	0
Repayments and sales	2,110	(2,662)	(6,859)	(8,247)
Accrual of unearned discounts	0	0	0	0
Amounts received pursuant to sales of loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	2,504	2,947	4,895	10,302
Total	2,504	2,947	4,895	10,302
Loans to REO	0		0
Interest rate lock commitments to loans held for sale	0	0	0	0
Mortgage servicing rights relating to delinquent loans to Agency		0	0	0
Ending balance	30,695	31,432	30,695	31,432
Changes in fair value recognized during the quarter/period relating to assets	496	348	1,705	2,268
Recurring [Member] \| Loans Held for Investment [Member]
Assets:
Beginning balance	1,592	1,854	1,705	1,866
Purchases and issuances	0	0	0	0
Repayments and sales	(15)	(99)	(85)	(139)
Accrual of unearned discounts	0	0	0	0
Amounts received pursuant to sales of loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	(53)	(9)	(96)	19
Total	(53)	(9)	(96)	19
Loans to REO	(163)		(163)
Interest rate lock commitments to loans held for sale	0	0	0	0
Mortgage servicing rights relating to delinquent loans to Agency		0	0	0
Ending balance	1,361	1,746	1,361	1,746
Changes in fair value recognized during the quarter/period relating to assets	(54)	(31)	(84)	(1)
Recurring [Member] \| Mortgage servicing rights [Member]
Assets:
Beginning balance	3,575,603	3,739,106	3,644,702	3,867,394
Purchases and issuances	0	0	0	0
Repayments and sales	(204,172)	0	(204,172)	0
Accrual of unearned discounts	0	0	0	0
Amounts received pursuant to sales of loans	16,926	45,744	88,188	136,783
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	125,403	(116,379)	(17,360)	(336,097)
Total	125,403	(116,379)	(17,360)	(336,097)
Loans to REO	0		0
Interest rate lock commitments to loans held for sale	0	0	0	0
Mortgage servicing rights relating to delinquent loans to Agency		284	2,402	675
Ending balance	3,513,760	3,668,755	3,513,760	3,668,755
Changes in fair value recognized during the quarter/period relating to assets	125,403	(116,379)	(38,927)	(336,097)
Recurring [Member] \| Loans Held For Sale [Member]
Assets:
Beginning balance	2,311	7,165	3,581	7,971
Purchases and issuances	2,005	(1,305)	10,899	1,826
Repayments and sales	(1,849)	(3,771)	(11,874)	(7,989)
Accrual of unearned discounts	0	0	0	0
Amounts received pursuant to sales of loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	(59)	245	(198)	526
Total	(59)	245	(198)	526
Loans to REO	0		0
Interest rate lock commitments to loans held for sale	0	0	0	0
Mortgage servicing rights relating to delinquent loans to Agency		0	0	0
Ending balance	2,408	2,334	2,408	2,334
Changes in fair value recognized during the quarter/period relating to assets	(3)	(15)	(150)	89
Recurring [Member] \| Interest Rate Lock Commitments with PFSI [Member]
Assets:
Beginning balance	2,945	6,485	2,348	444
Purchases and issuances	1,349	13,533	15,577	21,685
Repayments and sales	0	0	0	0
Accrual of unearned discounts	0	0	0	0
Amounts received pursuant to sales of loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	(17,451)	11,290	(20,897)	23,210
Total	(17,451)	11,290	(20,897)	23,210
Loans to REO	0		0
Interest rate lock commitments to loans held for sale	(2,929)	(25,819)	(13,114)	(39,850)
Mortgage servicing rights relating to delinquent loans to Agency		0	0	0
Ending balance	(16,086)	5,489	(16,086)	5,489
Changes in fair value recognized during the quarter/period relating to assets	(16,086)	5,489	(16,086)	5,489
Recurring [Member] \| Interest-only security payable [Member]
Liabilities:
Beginning balance	34,299	36,553	37,650	34,222
Changes in instrument-specific credit risk\Other factors	309	5	(3,042)	2,336
Ending balance	34,608	36,558	34,608	36,558
Changes in fair value recognized during the quarter/period relating to liability	309	5	(3,042)	2,336
Recurring [Member] \| Interest-only security payable [Member] \| Credit Risk [Member]
Liabilities:
Changes in instrument-specific credit risk\Other factors	0	0	0	0
Recurring [Member] \| Interest-only security payable [Member] \| Other Factors [Member]
Liabilities:
Changes in instrument-specific credit risk\Other factors	309	5	(3,042)	2,336
Recurring [Member] \| Interest-Only Stripped Mortgage-Backed Securities [Member]
Assets:
Beginning balance	68,934	79,052	72,502	86,260
Purchases and issuances	0	0	0	0
Repayments and sales	(3,809)	(4,387)	(11,870)	(13,547)
Accrual of unearned discounts	1,835	2,161	5,645	6,611
Amounts received pursuant to sales of loans	0	0	0	0
Changes in fair value included in income arising from:
Changes in instrument-specific credit risk	0	0	0	0
Other factors	8,304	(1,469)	8,987	(3,967)
Total	8,304	(1,469)	8,987	(3,967)
Loans to REO	0		0
Interest rate lock commitments to loans held for sale	0	0	0	0
Mortgage servicing rights relating to delinquent loans to Agency		0	0	0
Ending balance	75,264	75,357	75,264	75,357
Changes in fair value recognized during the quarter/period relating to assets	$ 8,304	$ (1,469)	$ 8,987	$ (3,967)

Fair value measurement with unobservable inputs reconciliation recurring basis accrual of unearned discount.

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

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

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

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

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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.

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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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This item represents the estimated amount of gains or losses included in earnings during the period attributable to changes in instrument-specific credit risk arising from loans and other receivables held as assets.

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Value transferred from mortgage loans to real estate owned (REO) in noncash transactions.

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