Long-Term Debt - Note Payable (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 16, 2022
During the period:
Unpaid principal balance	$ 5,768,570,000
Carrying value:
Notes payable	2,471,930,000		$ 1,942,646,000
Unsecured senior notes	1,780,833,000		1,779,920,000
Servicing advances, net	547,158,000		696,753,000
Mortgage servicing rights, at fair value	6,003,390,000		5,953,621,000
Other Assets	513,241,000		417,907,000
Notes payable
Repayments of notes payable	150,000,000
Asset Pledged as Collateral without Right
Carrying value:
Servicing advances, net	315,323,000		381,379,000
Mortgage servicing rights, at fair value	5,954,749,000		5,897,613,000
Other Assets	$ 31,909,000		$ 12,277,000
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	$ 31,909,000		$ 12,277,000
Note Payable
During the period:
Average balance	$ 2,092,056,000	$ 1,300,000,000
Weighted-average interest rate (as a percent)	7.72%	2.95%
Total interest expense	$ 40,778,000	$ 9,909,000
Carrying value:
Unpaid principal balance	2,480,000,000		1,950,000,000
Unamortized debt issuance costs	(8,070,000)		(7,354,000)
Notes payable	$ 2,471,930,000		$ 1,942,646,000
Weighted-average interest rate (as a percent)	8.21%		7.46%
Amortization of Financing Costs	$ 932,000	459,000
Notes payable
Maximum loan amount	2,480,000,000
Note Payable | SOFR
Notes payable
Maximum loan amount				$ 400,000,000
Committed amount of debt instrument				$ 350,000,000
Note Payable | Asset Pledged as Collateral without Right | Mortgage servicing rights
Carrying value:
Mortgage servicing rights, at fair value	5,954,749,000		$ 5,897,613,000
Note Payable | Asset Pledged as Collateral without Right | Servicing advances
Carrying value:
Servicing advances, net	315,323,000		381,379,000
Note Payable | Asset Pledged as Collateral without Right | Deposits. | Deposits
Carrying value:
Other Assets	21,074,000		12,277,000
Notes Payable Term Loan 2018-GT1 | LIBOR
Notes payable
Maximum loan amount	$ 650,000,000
Interest rate spread	3.85%
Notes Payable Term Loan 2018-GT2 | LIBOR
Notes payable
Maximum loan amount	$ 650,000,000
Interest rate spread	2.65%
Notes Payable Term Loan 2022-GT1 | SOFR
Long-Term debt
Maximum loan amount	$ 500,000,000
Notes payable
Interest rate spread	4.25%
Notes Payable Term Loan 2023-GT1 | SOFR
Notes payable
Maximum loan amount	$ 680,000,000
Interest rate spread	3.00%
Unsecured Senior Note
During the period:
Average balance	$ 1,800,000,000	$ 1,800,000,000
Weighted-average interest rate (as a percent)	5.07%	5.07%
Total interest expense	$ 23,428,000	$ 23,428,000
Unpaid principal balance	1,800,000,000		1,800,000,000
Unamortized debt issuance costs and premiums	(19,167,000)		(20,080,000)
Debt Instrument Unamortized Premium And Debt Issuance Costs Net	$ 1,780,833,000		$ 1,779,920,000
Weighted average interest rate (as a percent)	5.07%		5.07%
Carrying value:
Amortization of Financing Costs	$ 913,000	$ 913,000
Notes payable
Maximum loan amount	$ 1,800,000,000
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	5.38%
Unsecured Senior Notes Two Due October 2025
Notes payable
Maximum loan amount	$ 150,000,000
Interest rate spread	5.38%
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%
Loan and Security Agreement
Carrying value:
Unpaid principal balance			$ 150,000,000
Term Notes and Term Loans
Carrying value:
Unpaid principal balance	$ 2,480,000,000		$ 1,800,000,000