Long-Term Debt - Note Payable (Details) - USD ($)	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
During the period:
Unpaid principal balance	$ 7,064,948,000
Carrying value:
Notes payable	1,724,608,000		$ 2,048,972,000
Servicing advances, net	496,917,000		568,512,000
Mortgage servicing rights, at fair value	8,963,889,000		8,744,528,000
Other assets	$ 663,363,000		770,081,000
Notes payable
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]	us-gaap:SecuredOvernightFinancingRateSofrMember
Asset Pledged as Collateral without Right
Carrying value:
Servicing advances, net	$ 303,106,000		357,939,000
Mortgage servicing rights, at fair value	$ 8,802,948,000		$ 8,609,388,000
Assets, Pledging Purpose [Extensible Enumeration]	Notes payable		Notes payable
Other assets	$ 13,768,000		$ 16,697,000
Asset Pledged as Collateral without Right | Mortgage servicing rights
Carrying value:
Assets, Pledging Purpose [Extensible Enumeration]	Notes payable		Notes payable
Asset Pledged as Collateral without Right | Deposits.
Carrying value:
Other assets	$ 13,768,000		$ 16,697,000
Asset Pledged as Collateral without Right | Deposits. | Deposits
Carrying value:
Other assets	13,768,000		16,697,000
Note Payable
During the period:
Average balance	$ 1,863,611,000	$ 1,950,330,000
Weighted-average interest rate (as a percent)	7.85%	8.92%
Total interest expense	$ 36,578,000	$ 44,006,000
Carrying value:
Unpaid principal balance	1,730,000,000		2,055,000,000
Unamortized debt issuance costs	(5,392,000)		(6,028,000)
Notes payable	$ 1,724,608,000		$ 2,048,972,000
Weighted-average interest rate (as a percent)	7.86%		7.81%
Amortization of Debt Issuance Costs	$ 513,000	750,000
Notes payable
Maximum loan amount	1,730,000,000
Note Payable | Asset Pledged as Collateral without Right | Servicing advances
Carrying value:
Servicing advances, net	303,106,000		$ 357,939,000
Note Payable | Asset Pledged as Collateral without Right | Mortgage servicing rights
Carrying value:
Mortgage servicing rights, at fair value	$ 8,802,948,000		$ 8,609,388,000
Assets, Pledging Purpose [Extensible Enumeration]	Notes payable		Notes payable
Note Payable expiring 2024
Notes payable
Maximum loan amount	$ 900,000,000
Committed amount of debt instrument	850,000,000
Notes Payable Term Loan 2022-GT1
Notes payable
Maximum loan amount	$ 500,000,000
Interest rate spread	4.25%
Notes Payable Term Loan 2024-GT1
Notes payable
Maximum loan amount	$ 425,000,000
Interest rate spread	3.20%
Notes Payable Term Loan 2023-GT1
Notes payable
Maximum loan amount	$ 680,000,000
Interest rate spread	3.00%
Notes Payable Term Loan 2023-GT2
Notes payable
Maximum loan amount	$ 125,000,000
Interest rate spread	3.00%
Unsecured Senior Note
During the period:
Average balance	$ 3,710,000,000	2,550,000,000
Total interest expense	$ 60,137,000	$ 38,832,000
Weighted-average interest rate (as a percent)	6.26%	5.90%
Unpaid principal balance	$ 4,050,000,000		$ 3,200,000,000
Unamortized debt issuance costs and premiums	(51,298,000)		(35,968,000)
Debt Instrument Unamortized Premium And Debt Issuance Costs Net	$ 3,998,702,000		$ 3,164,032,000
Weighted average interest rate (as a percent)	6.30%		6.15%
Carrying value:
Amortization of Debt Issuance Costs	$ 2,000,000	$ 1,400,000
Notes payable
Maximum loan amount	$ 4,050,000,000
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
Interest rate spread	5.375%
Unsecured Senior Notes Two Due October 2025
Notes payable
Maximum loan amount	$ 150,000,000
Interest rate spread	5.375%
Unsecured Senior Notes Due February 2029
Notes payable
Maximum loan amount	$ 650,000,000
Interest rate spread	4.25%
Unsecured Senior Notes Due September 2031
Notes payable
Maximum loan amount	$ 500,000,000
Interest rate spread	5.75%
Unsecured Senior Notes Due December 2029
Notes payable
Maximum loan amount	$ 750,000,000
Interest rate spread	7.875%
Unsecured Senior Notes Due November 2030
Notes payable
Maximum loan amount	$ 650,000,000
Interest rate spread	7.125%
Unsecured Senior Notes Due February 2033
Notes payable
Maximum loan amount	$ 850,000,000
Interest rate spread	6.875%
Loan and Security Agreement
Carrying value:
Unpaid principal balance			$ 325,000,000
Term Loan Notes Payable
Carrying value:
Unpaid principal balance	$ 1,730,000,000		$ 1,730,000,000