RESIDENTIAL MORTGAGE LOANS - Schedule of Net Interest Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Interest income:
Loans held-for-investment, at fair value	$ 8,009	$ 11,550	$ 26,732	$ 32,298
Total interest income	53,090	61,048	154,232	212,263
Interest expense:
Loans held-for-investment, at fair value	4,823	3,793	14,342	9,955
Total interest expense	50,211	52,587	147,122	141,800
Net interest income	2,879	8,461	7,110	70,463
Loans held-for-sale, at lower of cost or fair value
Interest income:
Loans held-for-sale	1,206	1,613	4,594	5,429
Interest expense:
Loans held-for-sale	857	841	2,746	2,513
Loans held-for-sale, at fair value
Interest income:
Loans held-for-sale	43,875	47,885	122,906	174,536
Interest expense:
Loans held-for-sale	$ 44,531	$ 47,953	$ 130,034	$ 129,332