v3.26.1
Fair Value - Financial Statement Items Measured at Fair Value on a Recurring Basis (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Assets:    
Short-term investment at fair value $ 534,348 $ 410,037
Principal-only stripped mortgage-backed securities at fair value pledged to creditors 609,103 722,528
Loans held for sale 7,819,890 9,123,410
Derivative assets:    
Derivative asset, before netting 257,945 222,297
Netting (57,498) (36,779)
Total derivative assets 200,447 185,518
Investment in PennyMac Mortgage Investment Trust 846 941
Derivative liabilities:    
Derivative liability, before netting 77,224 54,797
Netting (42,661) (45,238)
Net amounts of liabilities presented in the consolidated balance sheet 34,563 9,559
Derivative liabilities with PennyMac Mortgage Investment Trust 5,239 6,247
PennyMac Mortgage Investment Trust    
Derivative assets:    
Total derivative assets 1,234 2,257
Recurring basis    
Assets:    
Short-term investment at fair value 534,348 410,037
Principal-only stripped mortgage-backed securities at fair value pledged to creditors 609,103 722,528
Loans held for sale 7,819,890 9,123,410
Derivative assets:    
Derivative asset, before netting 257,945 222,297
Netting (57,498) (36,779)
Total derivative assets 200,447 185,518
Investment in PennyMac Mortgage Investment Trust   941
Total assets 19,752,662 20,043,632
Derivative liabilities:    
Derivative liability, before netting 77,224 54,797
Netting (42,661) (45,238)
Net amounts of liabilities presented in the consolidated balance sheet 34,563 9,559
Mortgage servicing liabilities 1,522 1,572
Total liabilities 41,324 17,378
Recurring basis | Related Party | PennyMac Mortgage Investment Trust    
Derivative assets:    
Derivative asset, before netting 1,262 2,399
Netting (28) (142)
Total derivative assets 1,234 2,257
Mortgage servicing rights 10,586,794 9,598,941
Investment in PennyMac Mortgage Investment Trust 846  
Derivative liabilities:    
Derivative liability, before netting 5,267 6,389
Netting (28) (142)
Total liabilities 5,239 6,247
Recurring basis | Interest rate lock commitments    
Derivative assets:    
Derivative asset, before netting 145,095 131,536
Derivative liabilities:    
Derivative liability, before netting 3,887 4,260
Recurring basis | Interest rate lock commitments | Related Party | PennyMac Mortgage Investment Trust    
Derivative assets:    
Derivative asset, before netting 1,234 2,257
Derivative liabilities:    
Derivative liability, before netting 4,179 4,605
Recurring basis | Forward contracts | Purchases    
Derivative assets:    
Derivative asset, before netting 10,230 49,499
Derivative liabilities:    
Derivative liability, before netting 9,736 2,845
Recurring basis | Forward contracts | Sales    
Derivative assets:    
Derivative asset, before netting 15,879 16,399
Derivative liabilities:    
Derivative liability, before netting 46,426 47,692
Recurring basis | Forward contracts | Sales | Related Party | PennyMac Mortgage Investment Trust    
Derivative assets:    
Derivative asset, before netting 28 142
Derivative liabilities:    
Derivative liability, before netting 1,088 1,784
Recurring basis | Swaption    
Derivative assets:    
Derivative asset, before netting 65,152  
Derivative liabilities:    
Derivative liability, before netting 17,175  
Recurring basis | Put options on interest rate | Purchases    
Derivative assets:    
Derivative asset, before netting 21,453 22,769
Recurring basis | Call options on interest rate | Purchases    
Derivative assets:    
Derivative asset, before netting   2,086
Recurring basis | Total return swap    
Derivative assets:    
Derivative asset, before netting 136 8
Recurring basis | Level 1    
Assets:    
Short-term investment at fair value 534,348 410,037
Derivative assets:    
Derivative asset, before netting 21,453 24,855
Total derivative assets 21,453 24,855
Investment in PennyMac Mortgage Investment Trust   941
Total assets 556,647 435,833
Recurring basis | Level 1 | Related Party | PennyMac Mortgage Investment Trust    
Derivative assets:    
Investment in PennyMac Mortgage Investment Trust 846  
Recurring basis | Level 1 | Put options on interest rate | Purchases    
Derivative assets:    
Derivative asset, before netting 21,453 22,769
Recurring basis | Level 1 | Call options on interest rate | Purchases    
Derivative assets:    
Derivative asset, before netting   2,086
Recurring basis | Level 2    
Assets:    
Principal-only stripped mortgage-backed securities at fair value pledged to creditors 609,103 722,528
Loans held for sale 7,222,729 8,815,699
Derivative assets:    
Derivative asset, before netting 91,397 65,906
Total derivative assets 91,397 65,906
Total assets 7,923,257 9,604,275
Derivative liabilities:    
Derivative liability, before netting 73,337 50,537
Net amounts of liabilities presented in the consolidated balance sheet 73,337 50,537
Total liabilities 74,425 52,321
Recurring basis | Level 2 | Related Party | PennyMac Mortgage Investment Trust    
Derivative assets:    
Derivative asset, before netting 28 142
Total derivative assets 28 142
Derivative liabilities:    
Derivative liability, before netting 1,088 1,784
Total liabilities 1,088 1,784
Recurring basis | Level 2 | Forward contracts | Purchases    
Derivative assets:    
Derivative asset, before netting 10,230 49,499
Derivative liabilities:    
Derivative liability, before netting 9,736 2,845
Recurring basis | Level 2 | Forward contracts | Sales    
Derivative assets:    
Derivative asset, before netting 15,879 16,399
Derivative liabilities:    
Derivative liability, before netting 46,426 47,692
Recurring basis | Level 2 | Forward contracts | Sales | Related Party | PennyMac Mortgage Investment Trust    
Derivative assets:    
Derivative asset, before netting 28 142
Derivative liabilities:    
Derivative liability, before netting 1,088 1,784
Recurring basis | Level 2 | Swaption    
Derivative assets:    
Derivative asset, before netting 65,152  
Derivative liabilities:    
Derivative liability, before netting 17,175  
Recurring basis | Level 2 | Total return swap    
Derivative assets:    
Derivative asset, before netting 136 8
Recurring basis | Level 3    
Assets:    
Loans held for sale 597,161 307,711
Derivative assets:    
Derivative asset, before netting 145,095 131,536
Total derivative assets 145,095 131,536
Total assets 11,330,284 10,040,445
Derivative liabilities:    
Derivative liability, before netting 3,887 4,260
Net amounts of liabilities presented in the consolidated balance sheet 3,887 4,260
Mortgage servicing liabilities 1,522 1,572
Total liabilities 9,588 10,437
Recurring basis | Level 3 | Related Party | PennyMac Mortgage Investment Trust    
Derivative assets:    
Derivative asset, before netting 1,234 2,257
Total derivative assets 1,234 2,257
Mortgage servicing rights 10,586,794 9,598,941
Derivative liabilities:    
Derivative liability, before netting 4,179 4,605
Total liabilities 4,179 4,605
Recurring basis | Level 3 | Interest rate lock commitments    
Derivative assets:    
Derivative asset, before netting 145,095 131,536
Derivative liabilities:    
Derivative liability, before netting 3,887 4,260
Recurring basis | Level 3 | Interest rate lock commitments | Related Party | PennyMac Mortgage Investment Trust    
Derivative assets:    
Derivative asset, before netting 1,234 2,257
Derivative liabilities:    
Derivative liability, before netting $ 4,179 $ 4,605