CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Interest income:
Investments	$ 3,232,020		$ 3,558,015		$ 2,676,307
U.S. Treasury Securities	17,222		14,706		2,830
Securities loaned	9,903		6,897		3,997
Total interest income	3,259,145		3,579,618		2,683,134
Interest expense:
Repurchase agreements	577,243		426,769		397,971
Convertible Senior Notes	67,221		35,017		24,228
U.S. Treasury Securities sold, not yet purchased	15,114		13,081		2,649
Securities borrowed	7,594		5,459		3,377
Total interest expense	667,172		480,326		428,225
Net interest income	2,591,973		3,099,292		2,254,909
Other income (loss):
Investment advisory and other fee income	82,663		79,205		58,073
Net gains (losses) on disposition of investments	432,139		206,846		181,791
Net loss on extinguishment of 4% Convertible Senior Notes	(162,340)
Dividend income from affiliates	28,336		31,516		31,038
Net gains (losses) on trading assets	22,910		21,398		(2,351)
Net unrealized gain (losses) on Agency interest-only mortgage-backed securities	(59,937)		(106,657)
Income from underwriting			5,618		2,095
Subtotal	343,771		237,926		270,646
Realized gains (losses) on interest rate swaps	(893,769)	[1],[2]	(882,395)	[1],[2]	(735,107)	[1],[2]
Realized gains (losses) on termination of interest rate swaps	(2,385)
Unrealized gains (losses) on interest rate swaps	(32,219)		(1,815,107)		(318,832)
Subtotal	(928,373)		(2,697,502)		(1,053,939)
Total other income (loss)	(584,602)		(2,459,576)		(783,293)
Expenses:
Distribution fees					360
Compensation expense	190,702		206,251		146,958
Other general and administrative expenses	44,857		31,093		24,529
Total expenses	235,559		237,344		171,847
Income (loss) before income taxes and income from equity method investment in affiliate	1,771,812		402,372		1,299,769
Income taxes	(35,912)		(59,051)		(35,434)
Income (loss) on equity method investment in affiliate			1,140		2,945
Net income (loss)	1,735,900		344,461		1,267,280
Dividends on preferred stock	39,530		16,854		18,033
Net income (loss) available (related) to common shareholders	1,696,370		327,607		1,249,247
Net income (loss) per share available (related) to common shareholders:
Basic	$ 1.74		$ 0.37		$ 2.12
Diluted	$ 1.71		$ 0.37		$ 2.04
Weighted average number of common shares outstanding:
Basic	972,902,459		874,212,039		588,192,659
Diluted	1,005,755,057		874,518,938		625,307,174
Dividends Declared Per Share of Common Stock	$ 2.05		$ 2.44		$ 2.65
Net income (loss)	1,735,900		344,461		1,267,280
Other comprehensive income (loss):
Unrealized gains (losses) on available-for-sale securities	482,765		2,036,894		(639,783)
Unrealized loss on interest rate swaps			14,298		94,899
Reclassification adjustment for net (gains) losses included in net income (loss)	(438,511)		(206,846)		(181,791)
Other comprehensive income (loss)	44,254		1,844,346		(726,675)
Comprehensive income (loss)	$ 1,780,154		$ 2,188,807		$ 540,605

[1] Net interest payments on interest rate swaps is presented in the Company's Consolidated Statements of Operations and Comprehensive Income (Loss) as realized gains (losses) on interest rate swaps.

[2] Interest expense related to the Company's interest rate swaps is recorded in Realized losses on interest rate swaps on the Consolidated Statements of Operations and Comprehensive Income (Loss).