Statements Of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Interest income:
Interest income on mortgage-backed securities	$ 112,759	$ 86,935
Interest income on short-term cash investments	333	340
Total interest income	113,092	87,275
Interest expense	41,109	26,194
Net interest income	71,983	61,081
Operating expenses:
Management fee	3,842	3,092
Share based compensation	429	207
General and administrative	913	559
Total operating expenses	5,184	3,858
Other income:
Net gain on sale of mortgage-backed securities	2,505
Total other income	2,505
Net income	$ 69,304	$ 57,223
Earnings per share - common stock, basic	$ 0.89	$ 0.96
Earnings per share - common stock, diluted	$ 0.89	$ 0.96
Dividends declared per share	$ 0.90	$ 1.00
Weighted average shares outstanding	77,610,117	59,442,488