Concentration of Third-party Mortgage Purchasers - Percent of Mortgage Loans Sold to Third-party Purchasers (Details) - Customer Concentration Risk - Mortgage Loans Sold	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Freddie Mac
Concentration Risk [Line Items]
Concentration risk percentage	23.00%	6.00%	3.00%
PennyMac Loan Services, LLC
Concentration Risk [Line Items]
Concentration risk percentage	16.00%	15.00%	37.00%
PHH Mortgage
Concentration Risk [Line Items]
Concentration risk percentage	16.00%	0.00%	0.00%
Ginnie Mae
Concentration Risk [Line Items]
Concentration risk percentage	11.00%	10.00%	9.00%
Fannie Mae
Concentration Risk [Line Items]
Concentration risk percentage	5.00%	32.00%	19.00%
JPMorgan Chase
Concentration Risk [Line Items]
Concentration risk percentage	4.00%	4.00%	13.00%