Long-Term Debt - Note Payable (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) Lender	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
During the year:
Unpaid principal balance	$ 6,609,703,000		$ 6,609,703,000
Carrying value:
Notes payable	1,723,632,000		1,723,632,000		$ 1,873,415,000
Servicing advances, net	400,764,000		400,764,000		694,038,000
Mortgage servicing rights, at fair value	7,752,292,000		7,752,292,000		7,099,348,000
Other assets	642,189,000		$ 642,189,000		582,460,000
Notes payable
Number Of Lenders | Lender			2
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]			us-gaap:SecuredOvernightFinancingRateSofrMember
Asset Pledged as Collateral without Right
Carrying value:
Servicing advances, net	232,766,000		$ 232,766,000		354,831,000
Mortgage servicing rights, at fair value	$ 7,656,519,000		$ 7,656,519,000		$ 7,033,892,000
Assets, Pledging Purpose [Extensible Enumeration]	Notes payable		Notes payable		Notes payable
Other assets	$ 16,082,000		$ 16,082,000		$ 15,653,000
Asset Pledged as Collateral without Right | Mortgage servicing rights
Carrying value:
Assets, Pledging Purpose [Extensible Enumeration]	Notes payable		Notes payable		Notes payable
Asset Pledged as Collateral without Right | Deposits.
Carrying value:
Other assets	$ 16,082,000		$ 16,082,000		$ 15,653,000
Note Payable
During the year:
Average balance	$ 1,730,000,000	$ 2,484,348,000	$ 1,850,621,000	$ 2,353,572,000
Weighted-average interest rate (as a percent)	8.86%	8.78%	8.88%	8.40%
Total interest expense	$ 39,265,000	$ 55,676,000	$ 125,203,000	$ 150,271,000
Carrying value:
Unpaid principal balance	1,730,000,000		1,730,000,000		1,880,000,000
Unamortized debt issuance costs	(6,368,000)		(6,368,000)		(6,585,000)
Notes payable	$ 1,723,632,000		$ 1,723,632,000		$ 1,873,415,000
Weighted-average interest rate (as a percent)	8.39%		8.39%		8.82%
Amortization of Debt Issuance Costs	$ 726,000	689,000	$ 2,200,000	2,400,000
Notes payable
Maximum loan amount	1,730,000,000		1,730,000,000
Note Payable | Asset Pledged as Collateral without Right | Servicing advances
Carrying value:
Servicing advances, net	232,766,000		232,766,000		$ 354,831,000
Note Payable | Asset Pledged as Collateral without Right | Mortgage servicing rights
Carrying value:
Mortgage servicing rights, at fair value	7,656,519,000		7,656,519,000		7,033,892,000
Note Payable | Asset Pledged as Collateral without Right | Deposits. | Deposits
Carrying value:
Other assets	16,082,000		16,082,000		15,653,000
Note Payable expiring 2024
Notes payable
Maximum loan amount	900,000,000		900,000,000
Committed amount of debt instrument	850,000,000		850,000,000
Notes Payable Term Loan 2022-GT1
Notes payable
Maximum loan amount	500,000,000		$ 500,000,000
Interest rate spread			4.25%
Notes Payable Term Loan 2024-GT1
Notes payable
Maximum loan amount	425,000,000		$ 425,000,000
Interest rate spread			3.20%
Notes Payable Term Loan 2023-GT1
Notes payable
Maximum loan amount	680,000,000		$ 680,000,000
Interest rate spread			3.00%
Notes Payable Term Loan 2023-GT2
Notes payable
Maximum loan amount	125,000,000		$ 125,000,000
Interest rate spread			3.00%
Unsecured Senior Note
During the year:
Average balance	3,200,000,000	1,800,000,000	$ 2,860,766,000	1,800,000,000
Total interest expense	$ 51,147,000	$ 23,949,000	$ 133,947,000	$ 71,065,000
Weighted-average interest rate (as a percent)	6.15%	5.07%	6.03%	5.07%
Unpaid principal balance	$ 3,200,000,000		$ 3,200,000,000		2,550,000,000
Unamortized debt issuance costs and premiums	(37,761,000)		(37,761,000)		(30,349,000)
Debt Instrument Unamortized Premium And Debt Issuance Costs Net	$ 3,162,239,000		$ 3,162,239,000		$ 2,519,651,000
Weighted average interest rate (as a percent)	6.15%		6.15%		5.90%
Carrying value:
Amortization of Debt Issuance Costs	$ 1,800,000	$ 933,000	$ 4,700,000	$ 2,800,000
Notes payable
Maximum loan amount	3,200,000,000		$ 3,200,000,000
Redemption rate (as a percent)			100.00%
Unsecured Senior Note | Before October 15, 2022 with up to 40% principal redeemed
Notes payable
Redemption rate (as a percent)			40.00%
Unsecured Senior Notes One Due October 2025
Notes payable
Maximum loan amount	500,000,000		$ 500,000,000
Interest rate spread			5.375%
Unsecured Senior Notes Two Due October 2025
Notes payable
Maximum loan amount	150,000,000		$ 150,000,000
Interest rate spread			5.375%
Unsecured Senior Notes Due February 2029
Notes payable
Maximum loan amount	650,000,000		$ 650,000,000
Interest rate spread			4.25%
Unsecured Senior Notes Due September 2031
Notes payable
Maximum loan amount	500,000,000		$ 500,000,000
Interest rate spread			5.75%
Unsecured Senior Notes Due December 2029
Notes payable
Maximum loan amount	750,000,000		$ 750,000,000
Interest rate spread			7.875%
Unsecured Senior Notes Due November 2030
Notes payable
Maximum loan amount	650,000,000		$ 650,000,000
Interest rate spread			7.125%
Term Notes and Term Loans
Carrying value:
Unpaid principal balance	$ 1,730,000,000		$ 1,730,000,000		$ 1,730,000,000
Freddie Mac MSR Note Payable
Carrying value:
Unpaid principal balance					$ 150,000,000