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	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	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	Noncontrolling interest
Beginning balance at Dec. 31, 2013	$ 12,405,055	$ 177,088	$ 290,514	$ 445,457		$ 9,474	$ 14,765,761	$ (2,748,933)	$ (534,306)					$ 12,405,055
Net income (loss) attributable to Annaly	(842,083)								(842,083)					(842,083)
Net income (loss) attributable to noncontrolling interest	(196)																		$ (196)
Unrealized gains (losses) on available-for-sale securities	3,048,291							3,048,291						3,048,291
Reclassification adjustment for net (gains) losses included in net income (loss)	(94,475)							(94,475)						(94,475)
Stock compensation expense	1,072						1,072							1,072
Net proceeds from direct purchase and dividend reinvestment	2,370					2	2,368							2,370
Contingent beneficial conversion feature on 4% Convertible Senior Notes	17,308						17,308							17,308
Equity contributions from (distributions to) noncontrolling interest	5,486																		5,486
Common dividends declared, $1.20 per share	(1,137,079)								(1,137,079)					(1,137,079)
Ending balance at Dec. 31, 2014	13,333,781	177,088	290,514	445,457		9,476	14,786,509	204,883	(2,585,436)					13,328,491					5,290
Preferred dividends declared		(14,593)	(22,875)	(34,500)						$ (14,593)	$ (22,875)	$ (34,500)			$ (14,593)	$ (22,875)	$ (34,500)
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
Common dividends declared, $1.20 per share	(1,133,768)								(1,133,768)					(1,133,768)
Ending balance at Dec. 31, 2015	11,905,922	177,088	290,514	445,457		9,359	14,675,768	(377,596)	(3,324,616)					11,895,974					9,948
Preferred dividends declared		(14,593)	(22,875)	(34,500)						(14,593)	(22,875)	(34,500)			(14,593)	(22,875)	(34,500)
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)
Common dividends declared, $1.20 per share	(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	$ 10,189	$ 15,579,342	$ (1,085,893)	$ (3,136,017)					$ 12,568,180					$ 7,792
Preferred dividends declared		$ (14,593)	$ (22,875)	$ (34,500)	$ (10,292)					$ (14,593)	$ (22,875)	$ (34,500)	$ (10,292)		$ (14,593)	$ (22,875)	$ (34,500)	$ (10,292)