Stockholders' Equity - Preferred Stock (Details) - USD ($)			9 Months Ended	60 Months Ended
	Jul. 16, 2023	Dec. 31, 2019	Sep. 30, 2020	Jul. 15, 2023
Class of Stock
Preferred Stock, Shares Issued (in shares)		2,565,120	2,565,120
Aggregate liquidation preference		$ 450,000,000	$ 450,000,000
Preferred stock, shares outstanding (in shares)		2,565,120	2,565,120
Preferred stock
Class of Stock
Preferred Stock, Shares Issued (in shares)		2,565,120	2,565,120
Aggregate liquidation preference		$ 450,000,000	$ 450,000,000
Preferred stock, shares outstanding (in shares)		2,565,120
Preferred stock | Preferred Stock Series A
Class of Stock
Dividend rate per year		7.50%	7.50%
Preferred Stock, Shares Issued (in shares)		2,200,000	2,200,000
Depositary shares issued and outstanding		0	0
Liquidation preference per share		$ 25	$ 25
Aggregate liquidation preference		$ 55,000,000	$ 55,000,000
Preferred stock | Preferred Stock Series B
Class of Stock
Dividend rate per year		7.50%	7.50%
Preferred Stock, Shares Issued (in shares)		165,000	165,000
Depositary shares issued and outstanding		6,600,000	6,600,000
Liquidation preference per share		$ 1,000	$ 1,000
Aggregate liquidation preference		$ 165,000,000	$ 165,000,000
Preferred stock | Preferred Stock Series C
Class of Stock
Dividend rate per year		7.50%	7.50%
Preferred Stock, Shares Issued (in shares)		200,000	200,000
Depositary shares issued and outstanding		8,000,000	8,000,000
Liquidation preference per share		$ 1,000	$ 1,000
Aggregate liquidation preference		$ 200,000,000	$ 200,000,000
Preferred stock | Preferred Stock Series D
Class of Stock
Preferred Stock, Shares Issued (in shares)		120	120
Depositary shares issued and outstanding		0	0
Liquidation preference per share		$ 250,000	$ 250,000
Aggregate liquidation preference		$ 30,000,000	$ 30,000,000
Preferred stock | Subsequent Event | Preferred Stock Series D
Class of Stock
Dividend rate per year	5.4941%			7.00%
Dividend rate per year	six-month LIBOR