LOANS - Summary of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest income	$ 219,971	$ (6,451)
Net income (loss) attributable to Annaly	124,224	462,892
Residential Mortgage Loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Interest income	426,055	252,016
Net gains (losses) on disposal of investments	(9,993)	(2,117)
Net unrealized gains (losses) on instruments measured at fair value through earnings	240,830	(84,786)
Net income (loss) attributable to Annaly	$ 656,892	$ 165,113