RESIDENTIAL MORTGAGE LOANS - Schedule of Net Interest Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest income:
Loans held-for-investment, at fair value	$ 34,658	$ 45,287	$ 44,369
Total interest income	199,695	263,423	327,711
Interest expense:
Loans held-for-investment, at fair value	18,893	17,583	16,919
Total interest expense	184,409	202,056	197,665
Net interest income	15,286	61,367	130,046
Loans held-for-sale, at lower of cost or fair value
Interest income:
Loans held-for-sale	5,804	6,898	23,280
Interest expense:
Loans held-for-sale	3,615	3,402	21,333
Loans held-for-sale, at fair value
Interest income:
Loans held-for-sale	159,233	211,238	260,062
Interest expense:
Loans held-for-sale	$ 161,901	$ 181,071	$ 159,413