Fair Value - Quantitative Summary of Key Unobservable Inputs Used in Valuation of Interest Rate Lock Commitments (Detail) - USD ($) $ in Thousands	Sep. 30, 2026	Dec. 31, 2025
Pull-Through Rate [Member] \| Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	57.40%	50.50%
Pull-Through Rate [Member] \| Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	100.00%	100.00%
Pull-Through Rate [Member] \| Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	88.60%	90.90%
Servicing Fee Multiple [Member] \| Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	3.30%	1.70%
Servicing Fee Multiple [Member] \| Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	7.70%	8.40%
Servicing Fee Multiple [Member] \| Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	5.40%	5.40%
Percentage of Unpaid Principal Balance [Member] \| Minimum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	0.80%	0.40%
Percentage of Unpaid Principal Balance [Member] \| Maximum [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	2.50%	3.20%
Percentage of Unpaid Principal Balance [Member] \| Weighted Average [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Key inputs used in valuation of IRLCs	1.40%	1.90%
Interest Rate Lock Commitments with PFSI [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value, Assets	$ (16,086)	$ 2,348
Committed amount	$ 883,146	$ 1,207,859