CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Net interest income
Interest income	$ 555,026	$ 866,186
Interest expense	503,473	647,695
Net interest income	51,553	218,491
Realized and unrealized gains (losses)
Net interest component of interest rate swaps	(13,980)	134,035
Realized gains (losses) on termination or maturity of interest rate swaps	(397,561)	(588,256)
Unrealized gains (losses) on interest rate swaps	(2,827,723)	(390,556)
Subtotal	(3,239,264)	(844,777)
Net gains (losses) on disposal of investments and other	206,583	(93,916)
Net gains (losses) on other derivatives	206,426	(115,159)
Net unrealized gains (losses) on instruments measured at fair value through earnings	(730,160)	47,629
Loan loss provision	(99,326)	(5,703)
Subtotal	(416,477)	(167,149)
Total realized and unrealized gains (losses)	(3,655,741)	(1,011,926)
Other income (loss)	14,926	30,502
General and administrative expenses
Compensation and management fee	40,825	44,833
Other general and administrative expenses	36,804	38,904
Total general and administrative expenses	77,629	83,737
Income (loss) before income taxes	(3,666,891)	(846,670)
Income taxes	(26,702)	2,581
Net income (loss)	(3,640,189)	(849,251)
Net income (loss) attributable to noncontrolling interests	66	(101)
Net income (loss) attributable to Annaly	(3,640,255)	(849,150)
Dividends on preferred stock	35,509	32,494
Net income (loss) available (related) to common stockholders	$ (3,675,764)	$ (881,644)
Net income (loss) per share available (related) to common stockholders
Basic (in dollars per share)	$ (2.57)	$ (0.63)
Diluted (in dollars per share)	$ (2.57)	$ (0.63)
Weighted average number of common shares outstanding
Basic (in shares)	1,430,994,319	1,398,614,205
Diluted (in shares)	1,430,994,319	1,398,614,205
Net income (loss)	$ (3,640,189)	$ (849,251)
Other comprehensive income (loss)
Unrealized gains (losses) on available-for-sale securities	1,374,796	1,599,398
Reclassification adjustment for net (gains) losses included in net income (loss)	(391,616)	61,091
Other comprehensive income (loss)	983,180	1,660,489
Comprehensive income (loss)	(2,657,009)	811,238
Comprehensive income (loss) attributable to noncontrolling interests	66	(101)
Comprehensive income (loss) attributable to Annaly	(2,657,075)	811,339
Comprehensive income (loss) attributable to common stockholders	$ (2,692,584)	$ 778,845