Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	200,000,000	125,000,000
Common stock, shares issued (in shares)	94,152,000	65,290,000
Common stock, shares outstanding (in shares)	94,152,000	65,290,000
Agency Securities
Agency securities pledged	$ 3,995,804	$ 4,726,584
US Treasury Securities
Agency securities pledged	$ 98,859
Series C Preferred Stock
Preferred stock, par value (in dollars per share)	$ 0.001
Preferred stock, dividend rate	7.00%	7.00%
Preferred stock, shares issued (in shares)	6,847,000	5,347,000
Preferred stock, shares outstanding (in shares)	6,847,000	5,347,000
Preferred stock, aggregate liquidation preference	$ 171,175	$ 133,675