Mortgage Servicing Rights and Mortgage Servicing Liabilities - Activity in MSRs at Fair Value (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Activity in MSRs carried at fair value
Exchange of mortgage servicing spread for interest-only stripped mortgage-backed securities	$ 202,186	$ 98,066
Change in fair value due to:
Total change in fair value	433,342	605,568	$ (354,176)
Mortgage servicing rights
Activity in MSRs carried at fair value
Balance at beginning of period	7,099,348	5,953,621	3,878,078
MSRs resulting from loan sales	2,280,830	1,849,957	1,718,094
Additions - Purchases (purchase adjustments)			3,993
Additions - Transfer to Agency of MSRs relating to delinquent loans		305
Exchange of mortgage servicing spread for interest-only stripped mortgage-backed securities	(202,186)	(98,066)
Additions	2,078,644	1,751,586	1,722,087
Change in fair value due to:
Changes in inputs used in valuation model	407,423	56,757	877,324
Other changes in fair value	(840,887)	(662,616)	(523,868)
Total change in fair value	(433,464)	(605,859)	353,456
Balance at end of period	8,744,528	7,099,348	5,953,621
Unpaid principal balance of underlying loans at end of period	$ 426,055,220	$ 370,244,119	$ 314,567,639
Asset Pledged as Collateral without Right
Change in fair value due to:
Assets, Pledging Purpose [Extensible Enumeration]	Notes Payable	Notes Payable
Asset Pledged as Collateral without Right | Mortgage servicing rights
Activity in MSRs carried at fair value
Balance at beginning of period	$ 7,033,892
Change in fair value due to:
Balance at end of period	$ 8,609,388	$ 7,033,892
Assets, Pledging Purpose [Extensible Enumeration]	Notes Payable	Notes Payable