Net Gains on Loans Acquired for Sale - Summary of Net Gains on Mortgage Loans Acquired for Sale (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Non-cash gains:
Receipt of MSRs in mortgage loan sale transactions			$ (159,456)	$ (249,925)
Provision for losses relating to representations and warranties provided in loan sales:
Pursuant to loans sales	$ (459)	$ (448)	(917)	(2,126)
Changes in fair value of loans and derivatives
Net gains on loans acquired for sale	20,059	13,558	46,737	24,477
PennyMac Financial Services, Inc. [Member]
Changes in fair value of loans and derivatives
Net gains on loans acquired for sale	1,994	1,854	5,649	5,014
Nonaffiliates [Member]
Cash losses:
Sales of loans	(23,594)	(71,105)	(94,999)	(260,697)
Hedging activities	(72,868)	(30,155)	(116,797)	(52,822)
Cash gain, net of effects of cash hedging, on sale of mortgage loans acquired for sale	(96,462)	(101,260)	(211,796)	(313,519)
Non-cash gains:
Receipt of MSRs in mortgage loan sale transactions	87,588	58,560	159,456	249,925
Provision for losses relating to representations and warranties provided in loan sales:
Pursuant to loans sales	(459)	(448)	(917)	(2,126)
Reduction of liability due to change in estimate	5,180	4,365	18,598	7,920
Provision for losses relating to representations and warranties	4,721	3,917	17,681	5,794
Changes in fair value of loans and derivatives
Interest rate lock commitments	4,349	(2,050)	(1,631)	(2,870)
Loans	(9,528)	(1,710)	(3,721)	4,569
Hedging derivatives	27,397	54,247	81,099	75,564
Total non cash portion of gain on mortgage loans acquired for sale	22,218	50,487	75,747	77,263
Net cash of gain on mortgage loans acquired for sale	114,527	112,964	252,884	332,982
Net gains on loans acquired for sale	$ 18,065	$ 11,704	$ 41,088	$ 19,463