Note 13 - Income Taxes (Detail) - Reconciliation of GAAP Net Income to Estimated REIT Taxable Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
GAAP Net income	$ 10,976
Book to tax differences :
Net book/tax differences on Non-Agency Securities	(1,726)
Unrealized change in the fair value of derivatives	(3,444)
Income tax expense	2
Estimated taxable income	$ 5,808