CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Residential whole loans, carrying value	$ 3,843,153,000	$ 4,847,782,000
Residential whole loans, fair value	705,666,000	794,684,000
Servicing rights pledged as collateral	252,183,000	1,217,002,000
Financial agreements held at fair value	4,080,461,000	$ 0
Preferred stock, liquidation preference, value	$ 275,000,000
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	874,300	886,950
Common stock, shares issued (in shares)	453,333	452,369
Common stock, shares outstanding (in shares)	453,333	452,369
Collateral Pledged | Non-Agency MBS
Securities, at fair value, pledged as collateral	$ 152,765,000	$ 3,966,591,000
Series B Preferred Stock
Preferred stock par value (usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	8,050	8,050
Preferred Stock, dividend rate	7.50%	7.50%
Preferred stock, shares issued (in shares)	8,000	8,000
Preferred stock, shares outstanding (in shares)	8,000	8,000
Preferred stock, liquidation preference, value	$ 200,000,000	$ 200,000,000
Series C Preferred Stock
Preferred stock par value (usd per share)	$ 0.01
Preferred stock, shares authorized (in shares)	12,650
Preferred Stock, dividend rate	6.50%
Preferred stock, shares issued (in shares)	11,000