Commitments and Contingencies - Narrative (Details)		1 Months Ended	3 Months Ended			12 Months Ended
	Feb. 26, 2024 USD ($) $ / shares	Apr. 30, 2024 shares	Mar. 31, 2024 USD ($) loan $ / shares shares	Mar. 31, 2023 USD ($) shares	Jun. 30, 2020 series $ / shares shares	Dec. 31, 2023 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) series $ / shares shares
Commitments and Contingencies
Proceeds from issuance of private placement								$ 125,000,000
Number of preferred stock series issued | series								2
Number of warrants series issued | series					2
Warrant term (in years)			39 months		5 years
Class of warrant or right, outstanding (in shares) | shares			1,950,672	1,950,672	6,500,000
Investment warrants, exercise price (in dollars per share) | $ / shares					$ 10.00
Preferred stock, face value per share (in dollars per share) | $ / shares							$ 25.00
Class of warrant or right, shares repurchased and retired (in shares) | shares							4,549,328
Payments for repurchase and retirement of warrants			$ 0				$ 35,000,000
Warrant liability			2,054,000	$ 13,775,000		$ 16,644,000	$ 12,153,000
Sale of stock, termination of contract	$ 15,500,000
Preferred stock payable			12,600,000
Rithm
Commitments and Contingencies
Warrant term (in years)	5 years
Investment warrants, exercise price (in dollars per share) | $ / shares	$ 5.36
Fair value of warrants	$ 2,700,000
Fair value adjustment of warrants			700,000
Amortization of deferred issuance costs			700,000
Warrant liability			$ 2,100,000
Sale of stock, termination of contract	15,500,000
Rithm | Secured Debt | Line of Credit
Commitments and Contingencies
Original Principal	70,000,000
Sale of stock, consideration to be received on transaction	$ 14,000,000
Stock price of common stock (in dollars per share) | $ / shares	$ 4.87
Sale of stock, average trailing closing price, period (in days)	5 days
7.25% Series A preferred stock
Commitments and Contingencies
Preferred stock, shares issued (in shares) | shares			135,930			424,949		2,307,400
Preferred stock, fixed-to-floating rate cumulative redeemable			7.25%			7.25%	7.25%	7.25%
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares			$ 25.00			$ 25.00		$ 25.00
5.00% Series B preferred stock
Commitments and Contingencies
Preferred stock, shares issued (in shares) | shares			363,245			1,135,590		2,892,600
Preferred stock, fixed-to-floating rate cumulative redeemable			5.00%			5.00%	5.00%	5.00%
Preferred stock, liquidation preference per share (in dollars per share) | $ / shares			$ 25.00			$ 25.00		$ 25.00
Preferred stock, discount (in percent)							2.50%
Preferred Stock
Commitments and Contingencies
Deferred issuance costs			$ 0	$ 0			$ 8,200,000
Preferred Stock | 7.25% Series A preferred stock
Commitments and Contingencies
Stock repurchased and retired during period, shares (in shares) | shares							1,882,451
Exchange of shares (in shares) | shares			424,949
Preferred Stock | 5.00% Series B preferred stock
Commitments and Contingencies
Stock repurchased and retired during period, shares (in shares) | shares							1,757,010
Stock repurchased and retired during period							$ 88,700,000
Stock repurchased and retired during period, average price per share (in dollars per share) | $ / shares							$ 24.37
Exchange of shares (in shares) | shares			1,135,590
Common stock
Commitments and Contingencies
Exchange of shares (in shares) | shares			9,464,524
Preferred stock, shares exchanged, shares issued and to be issued (in shares) | shares			12,046,218
Common stock | Subsequent event
Commitments and Contingencies
Exchange of shares (in shares) | shares		2,581,694
Nonperforming loans | Purchase commitment | One-to-four family residences
Commitments and Contingencies
Number of mortgage loans on real estate | loan			0