Long-Term Debt - Note Payable (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Dec. 16, 2022	Dec. 31, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
During the year:
Unpaid principal balance			$ 3,769,449
Carrying value:
Notes payable		$ 1,942,646	1,873,415	$ 1,942,646
Unsecured senior notes		1,779,920	2,519,651	1,779,920
Servicing advances, net		696,753	694,038	696,753
Mortgage servicing rights, at fair value		5,953,621	7,099,348	5,953,621
Other Assets		$ 483,773	582,460	483,773
Notes payable
Debt Instrument Option To Extend Period		2 years
Repayments of Notes Payable			1,075,000
Asset Pledged as Collateral without Right
Carrying value:
Servicing advances, net		$ 381,379	354,831	381,379
Mortgage servicing rights, at fair value		$ 5,897,613	$ 7,033,892	$ 5,897,613
Assets, Pledging Purpose [Extensible Enumeration]		Notes payable	Notes payable	Notes payable
Other Assets		$ 12,277	$ 15,653	$ 12,277
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		$ 12,277	$ 15,653	$ 12,277
Note Payable
During the year:
Average balance			$ 2,421,124	$ 1,584,383	$ 1,300,000
Weighted-average interest rate (as a percent)			8.59%	4.88%	2.89%
Total interest expense			$ 211,085	$ 79,813	$ 39,782
Carrying value:
Unpaid principal balance		1,950,000	1,880,000	1,950,000
Unamortized debt issuance costs		(7,354)	(6,585)	(7,354)
Notes payable		$ 1,942,646	$ 1,873,415	$ 1,942,646
Weighted-average interest rate (as a percent)		7.46%	8.82%	7.46%
Amortization of Financing Costs			$ 3,200	$ 2,500	2,200
Notes payable
Maximum loan amount			1,730,000
Note Payable | SOFR
Notes payable
Maximum loan amount	$ 400,000
Committed amount of debt instrument	$ 350,000
Description of variable rate	SOFR
Note Payable | Asset Pledged as Collateral without Right | Mortgage servicing rights
Carrying value:
Mortgage servicing rights, at fair value		$ 5,897,613	7,033,892	5,897,613
Note Payable | Asset Pledged as Collateral without Right | Servicing advances
Carrying value:
Servicing advances, net		381,379	354,831	381,379
Note Payable | Asset Pledged as Collateral without Right | Deposits. | Deposit
Carrying value:
Other Assets		12,277	15,653	12,277
Notes Payable Term Loan 2018-GT2 | SOFR
Notes payable
Maximum loan amount			$ 425,000
Interest rate spread			3.40%
Notes Payable Term Loan 2022-GT1 | SOFR
Notes payable
Maximum loan amount			$ 500,000
Interest rate spread			4.25%
Notes Payable Term Loan 2023-GT1 | SOFR
Notes payable
Maximum loan amount			$ 680,000
Interest rate spread			3.00%
Notes Payable Term Loan 2023-GT2 | SOFR
Notes payable
Maximum loan amount			$ 125,000
Interest rate spread			3.00%
Unsecured Senior Note
During the year:
Average balance			$ 1,843,151	$ 1,800,000	$ 1,373,562
Weighted-average interest rate (as a percent)			5.13%	5.07%	4.94%
Total interest expense			$ 98,396	$ 95,014	$ 70,208
Carrying value:
Unpaid principal balance		1,800,000	2,550,000	1,800,000
Unamortized debt issuance costs		(20,080)	(30,349)	(20,080)
Unsecured senior notes		$ 1,779,920	$ 2,519,651	$ 1,779,920
Weighted-average interest rate (as a percent)		5.07%	5.90%	5.07%
Amortization of Financing Costs			$ 3,800	$ 3,700	$ 2,300
Notes payable
Maximum loan amount			$ 2,550,000
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
Coupon Rate (as a percent)			5.38%
Unsecured Senior Notes Two Due October 2025
Notes payable
Maximum loan amount			$ 150,000
Coupon Rate (as a percent)			5.38%
Unsecured Senior Notes Due February 2029
Notes payable
Maximum loan amount			$ 650,000
Coupon Rate (as a percent)			4.25%
Unsecured Senior Notes Due September 2031
Notes payable
Maximum loan amount			$ 500,000
Coupon Rate (as a percent)			5.75%
Unsecured Senior Notes Due December 2029
Notes payable
Maximum loan amount			$ 750,000
Coupon Rate (as a percent)			7.88%
Loan and Security Agreement
Carrying value:
Unpaid principal balance		$ 150,000	$ 150,000	150,000
Term Loan Notes Payable
Carrying value:
Unpaid principal balance		$ 1,800,000	$ 1,730,000	$ 1,800,000