Consolidated Statements of Income (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Interest income:
Mortgage-backed securities	$ 86,362	$ 96,307
Mortgage loans held for investment	467
Short-term cash investments	288	282
Total interest income	87,117	96,589
Interest expense	27,314	38,451
Net interest margin	59,803	58,138
Operating expenses:
Management fee	4,095	4,154
Share-based compensation	1,045	860
General and administrative	3,110	2,147
Total operating expenses	8,250	7,161
Other income (loss):
Net realized gain on sale of mortgage-backed securities	16,453	7,436
Gain on mortgage loans held for investment	244
Loss on derivative instruments, net	(102,785)	(41,615)
Total other loss	(86,088)	(34,179)
Net income (loss)	(34,535)	16,798
Dividends on preferred stock	5,481	5,480
Net income (loss) available to common shareholders	$ (40,016)	$ 11,318
Earnings (loss) per share - common stock, basic	$ (0.41)	$ 0.12
Earnings (loss) per share - common stock, diluted	$ (0.41)	$ 0.12
Dividends per share of common stock	$ 0.50	$ 0.50
Weighted average common shares outstanding, basic	96,783,199	96,606,081
Weighted average common shares outstanding, diluted	96,783,199	96,606,081