Consolidated Balance Sheets Parenthetical (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Assets:
Pledged Agency MBS	$ 2,456,815	$ 1,879,831
Pledged Non Agency MBS	$ 427,654	$ 415,195
Shareholders' Equity:
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	54,338,367	40,382,530
Common stock, shares outstanding	54,338,367	40,382,530