NET INCOME (LOSS) PER COMMON SHARE - Schedule of Net Income (Loss) per Share Reconciliation (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Net income (loss)	$ 1,011,768	$ (1,638,457)	$ 1,726,420
Net income (loss) attributable to noncontrolling interests	9,862	4,714	1,095
Net income (loss) attributable to Annaly	1,001,906	(1,643,171)	1,725,325
Dividends on preferred stock	154,551	141,676	110,623
Net income (loss) available (related) to common stockholders	$ 847,355	$ (1,784,847)	$ 1,614,702
Weighted average shares of common stock outstanding-basic (in shares)	521,737,554	494,541,323	411,348,484
Add: Effect of stock awards, if dilutive (in shares)	1,010,056	0	273,274
Weighted average shares of common stock outstanding-diluted (in shares)	522,747,610	494,541,323	411,621,758
Net income (loss) per share available (related) to common share
Basic (in dollars per share)	$ 1.62	$ (3.61)	$ 3.93
Diluted (in dollars per share)	$ 1.62	$ (3.61)	$ 3.92