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	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	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	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)	(184,007)								(184,007)				(184,007)
Unrealized gains (losses) on available-for-sale securities	1,872,427							1,872,427					1,872,427
Reclassification adjustment for net (gains) losses included in net income (loss)	(91,314)							(91,314)					(91,314)
Stock compensation expense	998						998						998
Net proceeds from direct purchase and dividend reinvestment	1,786					2	1,784						1,786
Contingent beneficial conversion feature on 4% Convertible Senior Notes	12,765						12,765						12,765
Common dividends declared, $0.30 per share	(852,786)								(852,786)				(852,786)
Ending balance at Sep. 30, 2014	13,110,948		177,088	290,514	445,457	9,476	14,781,308	(967,820)	(1,625,075)				13,110,948
Preferred dividends declared			(10,944)	(17,157)	(25,875)					$ (10,944)	$ (17,157)	$ (25,875)		$ (10,944)	$ (17,157)	$ (25,875)
Beginning balance at Dec. 31, 2014	13,333,781	[1]	177,088	290,514	445,457	9,476	14,786,509	204,883	(2,585,436)				13,328,491				$ 5,290
Net income (loss)	(203,483)								(203,483)				(203,483)
Net income (loss) attributable to noncontrolling interest	(436)																(436)
Unrealized gains (losses) on available-for-sale securities	116,154							116,154					116,154
Reclassification adjustment for net (gains) losses included in net income (loss)	(58,182)							(58,182)					(58,182)
Stock compensation expense	1,089						1,089						1,089
Net proceeds from direct purchase and dividend reinvestment	1,724					2	1,722						1,724
Equity contributions from (distributions to) noncontrolling interest	651																651
Common dividends declared, $0.30 per share	(852,989)								(852,989)				(852,989)
Ending balance at Sep. 30, 2015	$ 12,284,333		177,088	290,514	445,457	$ 9,478	$ 14,789,320	$ 262,855	$ (3,695,884)				$ 12,278,828				$ 5,505
Preferred dividends declared			$ (10,944)	$ (17,157)	$ (25,875)					$ (10,944)	$ (17,157)	$ (25,875)		$ (10,944)	$ (17,157)	$ (25,875)

[1] Derived from the audited consolidated financial statements at December 31, 2014.