Net Interest Expense (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Interest income:
Interest income	$ 172,952,000	$ 49,864,000	$ 301,430,000	$ 103,746,000
Interest expense:
Obligations under capital lease		5,000		20,000
Interest expense	178,642,000	71,127,000	310,413,000	148,434,000
Net interest expense	(5,690,000)	(21,263,000)	(8,983,000)	(44,688,000)
Nonrelated Party
Interest income:
Cash and short-term investments	21,127,000	405,000	37,372,000	977,000
Loans held for sale at fair value	78,780,000	36,777,000	139,773,000	85,890,000
Placement fees relating to custodial funds	73,024,000	12,682,000	124,243,000	16,879,000
Interest expense:
Assets sold under agreements to repurchase	87,480,000	18,949,000	146,703,000	42,719,000
Mortgage loan participation purchase and sale agreements	4,462,000	1,377,000	7,385,000	2,497,000
Notes payable	53,817,000	13,656,000	94,595,000	23,565,000
Unsecured senior notes	23,688,000	23,688,000	47,116,000	47,116,000
Obligations under capital lease		5,000		20,000
Interest shortfall on repayments of mortgage loans serviced for Agency securitizations	6,714,000	12,286,000	9,924,000	29,765,000
Interest on mortgage loan impound deposits	2,225,000	1,166,000	4,192,000	2,752,000
Other	256,000		498,000
Interest expense	178,642,000	71,127,000	310,413,000	148,434,000
Related Party | Townsgate Closing Services, LLC
Interest income:
Interest income	21,000		42,000
Loan Repo Facility
Interest expense:
Assets sold under agreements to repurchase	$ 87,480,000	$ 18,949,000	$ 146,703,000	$ 42,719,000