Equity (Narrative) (Details) - USD ($)			1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended
		Feb. 06, 2023	Aug. 04, 2023	Jun. 30, 2023	Mar. 31, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Mar. 21, 2023	Jun. 13, 2018
Subsidiary, Sale of Stock [Line Items]
Preferred Stock, Shares Issued				13,420,421			13,420,421		9,420,421
Proceeds from Issuance of Preferred Stock and Preference Stock	[1]						$ 96,850,000	$ 511,000
Preferred Stock, Shares Authorized				100,000,000			100,000,000		100,000,000
Preferred Stock, Par or Stated Value Per Share				$ 0.001			$ 0.001		$ 0.001
Common stock, shares authorized (in shares)				200,000,000			200,000,000		100,000,000
Common Stock, Par or Stated Value Per Share				$ 0.001			$ 0.001		$ 0.001
Dividends declared (in usd per share)				$ 0.45		$ 0.45	$ 0.90	$ 0.90
Dividends paid							$ (70,411,000)	$ (60,234,000)
Common shares issued and outstanding upon conversion of all convertible securities (in shares)				67,977,673			67,977,673		64,628,148
Number of shares authorized to be repurchased (in shares)											1,550,000
Preferred Stock, Shares Outstanding				13,420,421			13,420,421		9,420,421
Shares repurchased				(23,336)		(88,184)	(1,084,336)	(88,184)
Average price per share (USD per share)				$ 12.00		$ 13.2	$ 11.39	$ 13.20
Total cost				$ (280,000)	$ (12,072,000)	$ (1,164,000)	$ (12,400,000)	$ (1,200,000)
Incentive Fee, Loss Carryforward				42,000,000			42,000,000		$ 85,000,000
Stock Repurchase Program, Authorized Amount				$ 45,800,000			$ 45,800,000			$ 50,000,000
Stock Issued During Period, Shares, New Issues				0		383,700	4,433,861	2,568,700
Preferred ATM Program
Subsidiary, Sale of Stock [Line Items]
Maximum shares available to be issued under at the market program							100,000,000
Commissions and offering costs								$ 23,000
Proceeds from issuance of shares, net								$ 500,000
Stock Issued During Period, Shares, New Issues								20,421
Common ATM Program
Subsidiary, Sale of Stock [Line Items]
Maximum shares available to be issued under at the market program							10,000,000
Commissions and offering costs						$ 100,000		$ 700,000
Proceeds from issuance of shares, net						$ 6,700,000		$ 45,200,000
Stock Issued During Period, Shares, New Issues						383,700		2,568,700
Common ATM Programs
Subsidiary, Sale of Stock [Line Items]
Commissions and offering costs			$ 100,000				$ 900,000
Proceeds from issuance of shares, net			$ 11,800,000				$ 60,500,000
Stock Issued During Period, Shares, New Issues			855,364				4,433,861
2023 Common ATM Program
Subsidiary, Sale of Stock [Line Items]
Maximum shares available to be issued under at the market program							225,000,000
Series C Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Commissions and offering costs							$ 3,500,000
Proceeds from issuance of shares, net							$ 96,500,000
Series A Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage							6.75%
Preferred Stock, Par or Stated Value Per Share				$ 0.001			$ 0.001
Preferred Stock, Liquidation Preference Per Share				$ 25.00			$ 25.00
Preferred Stock Dividend Rate Variable Rate Spread							5.196%
Preferred Stock, Amount of Preferred Dividends in Arrears							$ 4,000,000		$ 2,500,000
Preferred Stock, Shares Outstanding				4,600,000			4,600,000		4,600,000
Series B Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage							6.25%
Preferred Stock, Par or Stated Value Per Share				$ 0.001			$ 0.001
Preferred Stock, Liquidation Preference Per Share				$ 25.00			$ 25.00
Preferred Stock Dividend Rate Variable Rate Spread							4.99%
Preferred Stock, Shares Outstanding				4,820,421			4,820,421		4,820,421
Series C Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Preferred Stock, Dividend Rate, Percentage		8.625%
Preferred Stock, Par or Stated Value Per Share		$ 0.001
Preferred Stock, Liquidation Preference Per Share		$ 25.00
Preferred Stock Dividend Rate Variable Rate Spread		5.13%
Preferred Stock, Shares Outstanding				4,000,000			4,000,000

[1] Net of discounts and commissions.