Long-Term Debt - Note Payable (Details) - USD ($)		1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 16, 2022	Jan. 31, 2023	Dec. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
During the period:
Unpaid principal balance			$ 3,004,690,000	$ 3,004,690,000
Carrying value:
Notes payable			1,942,646,000	1,942,646,000	$ 1,297,622,000
Unsecured senior notes			1,779,920,000	1,779,920,000	1,776,219,000
Servicing advances, net			696,753,000	696,753,000	702,160,000
Mortgage servicing rights, at fair value			5,953,621,000	5,953,621,000	3,878,078,000
Other Assets			$ 417,907,000	417,907,000	616,616,000
Notes payable
Debt instrument option to extend period			2 years
Asset Pledged as Collateral without Right
Carrying value:
Servicing advances, net			$ 381,379,000	381,379,000	232,107,000
Mortgage servicing rights, at fair value			$ 5,897,613,000	$ 5,897,613,000	$ 3,856,791,000
Assets, Pledging Purpose [Extensible Enumeration]			Notes payable	Notes payable	Notes payable
Other Assets			$ 12,277,000	$ 12,277,000	$ 45,294,000
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			$ 12,277,000	$ 12,277,000	$ 36,632,000
Note Payable
During the period:
Average balance				$ 1,584,383,000	$ 1,300,000,000	$ 1,300,000,000
Weighted-average interest rate (as a percent)				4.88%	2.89%	3.42%
Total interest expense				$ 79,813,000	$ 39,782,000	$ 46,222,000
Carrying value:
Unpaid principal balance			1,950,000,000	1,950,000,000	1,300,000,000
Unamortized debt issuance costs			(7,354,000)	(7,354,000)	(2,378,000)
Notes payable			$ 1,942,646,000	$ 1,942,646,000	$ 1,297,622,000
Weighted-average interest rate (as a percent)			7.46%	7.46%	2.84%
Amortization of Financing Costs				$ 2,500,000	$ 2,200,000	1,800,000
Notes payable
Maximum loan amount			$ 1,800,000,000	1,800,000,000
Debt instrument extension period		2 years
Note Payable | SOFR
Notes payable
Maximum loan amount	$ 400,000,000
Committed amount of debt instrument	$ 350,000,000
Description of variable rate	SOFR
Note Payable | Asset Pledged as Collateral without Right | Mortgage servicing rights
Carrying value:
Mortgage servicing rights, at fair value			5,897,613,000	5,897,613,000	3,856,791,000
Note Payable | Asset Pledged as Collateral without Right | Servicing advances
Carrying value:
Servicing advances, net			381,379,000	381,379,000	232,107,000
Note Payable | Asset Pledged as Collateral without Right | Deposits. | Deposit
Carrying value:
Other Assets			12,277,000	$ 12,277,000	36,632,000
Notes Payable Term Loan 2018-GT1
Notes payable
Debt instrument option to extend period				2 years
Debt instrument extension period		2 years
Notes Payable Term Loan 2018-GT1 | LIBOR
Notes payable
Maximum loan amount			650,000,000	$ 650,000,000
Interest rate spread				2.85%
Notes Payable Term Loan 2018-GT2
Notes payable
Debt instrument option to extend period				2 years
Notes Payable Term Loan 2018-GT2 | LIBOR
Notes payable
Maximum loan amount			650,000,000	$ 650,000,000
Interest rate spread				2.65%
Notes Payable Term Loan 2022-GT1 | SOFR
Notes payable
Maximum loan amount			500,000,000	$ 500,000,000
Interest rate spread				4.25%
Unsecured Senior Note
During the period:
Average balance				$ 1,800,000,000	$ 1,373,562,000	$ 158,743,000
Weighted-average interest rate (as a percent)				5.07%	4.94%	5.38%
Total interest expense				$ 95,014,000	$ 70,208,000	$ 8,774,000
Carrying value:
Unpaid principal balance			1,800,000,000	1,800,000,000	1,800,000,000
Unamortized debt issuance costs			(20,080,000)	(20,080,000)	(23,781,000)
Unsecured senior notes			$ 1,779,920,000	$ 1,779,920,000	$ 1,776,219,000
Weighted-average interest rate (as a percent)			5.07%	5.07%	5.07%
Amortization of Financing Costs				$ 3,700,000	$ 2,300,000	$ 225,000
Notes payable
Maximum loan amount			$ 1,800,000,000	$ 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	$ 500,000,000
Coupon Rate (as a percent)				5.38%
Unsecured Senior Notes Two Due October 2025
Notes payable
Maximum loan amount			150,000,000	$ 150,000,000
Coupon Rate (as a percent)				5.38%
Unsecured Senior Notes Due February 2029
Notes payable
Maximum loan amount			650,000,000	$ 650,000,000
Coupon Rate (as a percent)				4.25%
Unsecured Senior Notes Due September 2031
Notes payable
Maximum loan amount			500,000,000	$ 500,000,000
Coupon Rate (as a percent)				5.75%
Loan and Security Agreement
Carrying value:
Unpaid principal balance			150,000,000	$ 150,000,000
Term Loan Notes Payable
Carrying value:
Unpaid principal balance			$ 1,800,000,000	$ 1,800,000,000	$ 1,300,000,000