Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands									3 Months Ended		12 Months Ended					13 Months Ended	55 Months Ended
	Feb. 22, 2022	Nov. 12, 2021	Oct. 15, 2021	Jul. 30, 2021	Jul. 29, 2021	Jul. 09, 2021	Feb. 05, 2020	Jan. 25, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022		Dec. 31, 2021		Dec. 31, 2020	Jul. 29, 2022	Dec. 31, 2022	Jun. 13, 2018
Subsidiary, Sale of Stock [Line Items]
Preferred Stock, Shares Issued									9,420,421	9,400,000	9,420,421		9,400,000				9,420,421
Proceeds from Issuance of Preferred Stock and Preference Stock											$ 511	[1]	$ 116,220	[1]	$ 0
Preferred Stock, Shares Authorized									100,000,000	100,000,000	100,000,000		100,000,000				100,000,000
Preferred Stock, Par or Stated Value Per Share									$ 0.001	$ 0.001	$ 0.001		$ 0.001				$ 0.001
Common stock, shares authorized (in shares)									100,000,000	100,000,000	100,000,000		100,000,000				100,000,000
Common Stock, Par or Stated Value Per Share									$ 0.001	$ 0.001	$ 0.001		$ 0.001				$ 0.001
Dividends declared (in usd per share)											$ 1.80		$ 1.64		$ 1.26
Dividends paid											$ (123,065)		$ (85,704)		$ (65,026)
Common shares issued and outstanding upon conversion of all convertible securities (in shares)									64,628,148	58,180,342	64,628,148		58,180,342				64,628,148
Number of shares authorized to be repurchased (in shares)																		1,550,000
Shares repurchased (in shares)									(40,000)		(128,184)		0		(290,050)		(830,149)
Average price per share (USD per share)									$ 12.38		$ 12.94				$ 10.54		$ 13.29
Total cost									$ (500)		$ (1,659)				$ (3,056)		$ (11,000)
Shares Issued As Payment of Incentive Fee, Shares	19,094,000	28,453,000		37,373,000			637,000				19,094		67,875		637
Stock Issued During Period, Value, New Issues			$ 103,500													$ 113,100
Preferred Stock, Shares Outstanding									9,420,421	9,400,000	9,420,421		9,400,000				9,420,421
Stock Issued During Period, Shares, New Issues			5,750,000			6,000,000		5,290,000			6,459,070		13,602,900		5,290,000	6,303,000
Proceeds from issuance of shares, net								$ 95,300
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										$ 400	$ 1,300		$ 400
Stock Issued During Period, Shares, New Issues										1,549,900	6,459,070		1,549,900
Proceeds from issuance of shares, net										$ 28,200	$ 99,200		$ 28,200
Over-Allotment Option [Member]
Subsidiary, Sale of Stock [Line Items]
Stock Issued During Period, Shares, New Issues			750,000		303,000			690,000
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
Stock Issued During Period, Shares, New Issues											20,421
Proceeds from issuance of shares, net											$ 500
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						$ 0.001
Preferred Stock, Liquidation Preference Per Share									$ 25.00		$ 25.00						$ 25.00
Preferred Stock Dividend Rate Variable Rate Spread											5.196%
Preferred Stock, Amount of Preferred Dividends in Arrears											$ 2,500		$ 1,600
Preferred Stock, Shares Outstanding									4,600,000	4,600,000	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						$ 0.001
Preferred Stock, Liquidation Preference Per Share									$ 25.00		$ 25.00						$ 25.00
Preferred Stock Dividend Rate Variable Rate Spread											4.99%
Preferred Stock, Shares Outstanding									4,820,421	4,800,000	4,820,421		4,800,000				4,820,421
Operating Partnership Units [Member]
Subsidiary, Sale of Stock [Line Items]
Stock issued during period, shares, conversion of units											4,066		5,710		133,154

[1] Net of discounts and commissions.