CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total		7.875% Series A Cumulative Redeemable Preferred Stock	7.625% Series C Cumulative Redeemable Preferred Stock	7.50% Series D Cumulative Redeemable Preferred Stock	7.625% Series E Cumulative Redeemable Preferred Stock	6.95% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock	Preferred Stock	Preferred Stock 7.875% Series A Cumulative Redeemable Preferred Stock	Preferred Stock 7.625% Series C Cumulative Redeemable Preferred Stock	Preferred Stock 7.50% Series D Cumulative Redeemable Preferred Stock	Preferred Stock 7.625% Series E Cumulative Redeemable Preferred Stock	Preferred Stock 6.95% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock	Common Stock Par Value	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Accumulated Deficit 7.875% Series A Cumulative Redeemable Preferred Stock	Accumulated Deficit 7.625% Series C Cumulative Redeemable Preferred Stock	Accumulated Deficit 7.50% Series D Cumulative Redeemable Preferred Stock	Accumulated Deficit 7.625% Series E Cumulative Redeemable Preferred Stock	Accumulated Deficit 6.95% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock	Total Stockholders’ Equity	Total Stockholders’ Equity 7.875% Series A Cumulative Redeemable Preferred Stock	Total Stockholders’ Equity 7.625% Series C Cumulative Redeemable Preferred Stock	Total Stockholders’ Equity 7.50% Series D Cumulative Redeemable Preferred Stock	Total Stockholders’ Equity 7.625% Series E Cumulative Redeemable Preferred Stock	Total Stockholders’ Equity 6.95% Series F Fixed-to-Floating Rate Cumulative Redeemable Preferred Stock	Noncontrolling Interest
Beginning balance at Dec. 31, 2014	$ 13,333,781								$ 177,088	$ 290,514	$ 445,457	$ 0	$ 0	$ 9,476	$ 14,786,509	$ 204,883	$ (2,585,436)						$ 13,328,491						$ 5,290
Net income (loss) attributable to Annaly	466,556																466,556						466,556
Net income (loss) attributable to noncontrolling interest	(809)																												(809)
Unrealized gains (losses) on available-for-sale securities	(531,952)															(531,952)							(531,952)
Reclassification adjustment for net (gains) losses included in net income (loss)	(50,527)															(50,527)							(50,527)
Stock compensation expense	1,156														1,156								1,156
Net proceeds from direct purchase and dividend reinvestment	2,246													2	2,244								2,246
Buyback of common stock	(114,260)													(119)	(114,141)								(114,260)
Equity contributions from (distributions to) noncontrolling interest	5,467																												5,467
Preferred dividends declared			$ (14,593)	$ (22,875)	$ (34,500)													$ (14,593)	$ (22,875)	$ (34,500)				$ (14,593)	$ (22,875)	$ (34,500)
Common dividends declared	(1,133,768)																(1,133,768)						(1,133,768)
Ending balance at Dec. 31, 2015	11,905,922								177,088	290,514	445,457	0	0	9,359	14,675,768	(377,596)	(3,324,616)						11,895,974						9,948
Net income (loss) attributable to Annaly	1,433,756																1,433,756						1,433,756
Net income (loss) attributable to noncontrolling interest	(970)																												(970)
Unrealized gains (losses) on available-for-sale securities	(686,414)															(686,414)							(686,414)
Reclassification adjustment for net (gains) losses included in net income (loss)	(21,883)															(21,883)							(21,883)
Stock compensation expense	7,047														7,047								7,047
Net proceeds from direct purchase and dividend reinvestment	2,362													2	2,360								2,362
Buyback of common stock	(102,712)													(111)	(102,601)								(102,712)
Acquisition of subsidiary	1,285,207											287,500		939	996,768								1,285,207
Equity contributions from (distributions to) noncontrolling interest	(1,186)																												(1,186)
Preferred dividends declared			(14,593)	(22,875)	(34,500)	$ (10,292)	$ 0											(14,593)	(22,875)	(34,500)	$ (10,292)			(14,593)	(22,875)	(34,500)	$ (10,292)
Common dividends declared	(1,162,897)																(1,162,897)						(1,162,897)
Ending balance at Dec. 31, 2016	12,575,972								177,088	290,514	445,457	287,500	0	10,189	15,579,342	(1,085,893)	(3,136,017)						12,568,180						7,792
Net income (loss) attributable to Annaly	1,569,604																1,569,604						1,569,604
Net income (loss) attributable to noncontrolling interest	(588)																												(588)
Unrealized gains (losses) on available-for-sale securities	(89,997)															(89,997)							(89,997)
Reclassification adjustment for net (gains) losses included in net income (loss)	49,870															49,870							49,870
Stock compensation expense	1,406														1,406								1,406
Redemption of preferred stock	(185,312)							$ (177,088)							(8,224)								(185,312)
Net proceeds from direct purchase and dividend reinvestment	2,542													2	2,540								2,542
Net proceeds from issuance of stock	1,647,606						696,910						696,910	1,405	1,646,201								1,647,606					$ 696,910
Equity contributions from (distributions to) noncontrolling interest	(1,104)																												(1,104)
Preferred dividends declared			$ (9,527)	$ (22,875)	$ (34,500)	$ (21,922)	$ (20,811)											$ (9,527)	$ (22,875)	$ (34,500)	$ (21,922)	$ (20,811)		$ (9,527)	$ (22,875)	$ (34,500)	$ (21,922)	$ (20,811)
Common dividends declared	(1,285,701)																(1,285,701)						(1,285,701)
Ending balance at Dec. 31, 2017	$ 14,871,573	[1]							$ 0	$ 290,514	$ 445,457	$ 287,500	$ 696,910	$ 11,596	$ 17,221,265	$ (1,126,020)	$ (2,961,749)						$ 14,865,473						$ 6,100

[1] As a result of a change to a clearing organization’s rulebook effective January 3, 2017, beginning with the first quarter 2017 and in subsequent periods the Company is presenting the fair value of centrally cleared interest rate swaps net of variation margin pledged under such transactions. The variation margin was previously reported under cash and cash equivalents and is currently reported as a reduction to interest rate swaps, at fair value. Balances reported prior to the effective date will not be adjusted.