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, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net income (loss)	$ 1,726,420	$ 2,396,280	$ (889,772)
Net income (loss) attributable to noncontrolling interests	1,095	6,384	1,391
Net income (loss) attributable to Annaly	1,725,325	2,389,896	(891,163)
Dividends on preferred stock	110,623	107,532	142,036
Net income (loss) available (related) to common stockholders	$ 1,614,702	$ 2,282,364	$ (1,033,199)
Weighted average shares of common stock outstanding-basic (in shares)	411,348,484	356,856,520	353,664,860
Add: Effect of stock awards, if dilutive (in shares)	273,274	285,731	0
Weighted average shares of common stock outstanding-diluted (in shares)	411,621,758	357,142,251	353,664,860
Net income (loss) per share available (related) to common share
Basic (in dollars per share)	$ 3.93	$ 6.40	$ (2.92)
Diluted (in dollars per share)	$ 3.92	$ 6.39	$ (2.92)