LOANS - Investment Loan Activity (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2023 USD ($)
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning balance January 1, 2023	$ 1,809,832	[1],[2]
Ending balance June 30, 2023	1,154,320	[2]
Transfer of residential loans to securitization vehicles, carrying value, noncash	2,500,000
Residential
SEC Schedule, 12-29, Real Estate Companies, Investment in Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning balance January 1, 2023	1,809,832
Purchases / originations	1,934,157
Sales and transfers	(2,544,578)
Principal payments	(58,070)
Gains / (losses)	16,751
(Amortization) / accretion	(3,772)
Ending balance June 30, 2023	$ 1,154,320

[1] (1)Derived from the audited consolidated financial statements at December 31, 2022.

[2] (4)Includes $1.1 million and $1.3 million of residential mortgage loans held for sale at June 30, 2023 and December 31, 2022, respectively.