Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Assets
Mortgage-backed securities, at fair value (including pledged assets of $17,012,472 and $9,089,295 at December 31, 2011 and 2010, respectively)	$ 17,741,873	$ 9,587,216
Cash and cash equivalents	347,045	112,626
Restricted cash	237,014	75,422
Unsettled purchased mortgage-backed securities, at fair value	49,630	49,710
Accrued interest receivable	63,025	37,973
Principal payments receivable	105,333	84,151
Debt security, held to maturity, at cost	15,000	15,000
Interest rate hedge asset	0	23,944
Other assets	27,799	20,937
Total assets	18,586,719	10,006,979
Liabilities and shareholders' equity
Repurchase agreements	16,162,375	8,681,060
Payable for unsettled securities	48,999	49,774
Accrued interest payable	4,596	3,177
Interest rate hedge liability	219,167	71,681
Dividend payable	69,141	46,116
Accounts payable and other liabilities	2,253	9,687
Total liabilities	16,506,531	8,861,495
Shareholders' equity:
Preferred stock, $.001 par value, 10,000,000 shares authorized, none outstanding at December 31, 2011 and 2010
Common stock, $.001 par value, 100,000,000 shares authorized, 76,823,220 and 46,115,990 shares issued and outstanding at December 31, 2011 and 2010, respectively	77	46
Additional paid-in capital	1,904,748	1,043,027
Retained earnings (accumulated deficit)	2,041	(3,480)
Accumulated other comprehensive income	173,322	105,891
Total shareholders' equity	2,080,188	1,145,484
Total liabilities and shareholders' equity	$ 18,586,719	$ 10,006,979