LOANS - Summary of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest income	$ 19,463	$ 580,928
Net income (loss) attributable to Annaly	(844,256)	2,022,255
Residential Mortgage Loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest income	147,231	73,465
Net gains (losses) on disposal of investments	(776)	(7,338)
Net unrealized gains (losses) on instruments measured at fair value through earnings	260,441	(415,248)
Net income (loss) attributable to Annaly	$ 406,896	$ (349,121)