Condensed Consolidated Statement of Changes in Equity - USD ($) $ in Thousands		Total	Total Stockholders' Equity	Common Stock	Additional Paid-in Capital	Retained Earnings/(Accumulated Deficit)	Non-controlling Interest	Preferred Stock [Member]	Preferred Stock [Member] Total Stockholders' Equity	Preferred Stock [Member] Preferred Stock [Member]	Common Stock		Common Stock Total Stockholders' Equity	Common Stock Common Stock	Common Stock Additional Paid-in Capital
Beginning balance (in shares) at Dec. 31, 2017		31,335,938
Beginning balance at Dec. 31, 2017		$ 620,961	$ 600,099				$ 20,862
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM OPERATIONS
Shares Issued As Payment of Incentive Fee		71	71
Contributions from non-controlling interests		21,532					21,532
Dividends		50,736	50,388				348				$ 49,576
Distributions to non-controlling interests		(23,853)					(23,853)
Adjustment to non-controlling interests		$ 0	(369)				369
Stock issued during period, shares, conversion of units		(3,334)
Repurchase of shares of common stock (in shares)		(1,547,148)
Repurchase of shares of common stock		$ (23,131)	(23,131)
Share-based long term incentive plan unit redemption and distribution		0	(9,537)				9,537
Share-based long term incentive plan unit awards		$ 415	412				3
Ending balance (in shares) at Dec. 31, 2018		29,796,601		29,796,601
Ending balance at Dec. 31, 2018		$ 595,170	563,833		$ 665,356	$ (101,523)	31,337
Change In Shareholders' Equity Resulting From Operations [Abstract]
Net investment income		43,125
Net realized gain (loss) on investments, financial derivatives, and foreign currency transactions		31,388
Change in net unrealized gain (loss) on investments, other secured borrowings, financial derivatives, and foreign currency translation		(24,602)
Net increase in equity resulting from operations		49,911	46,676				3,235
Net increase (decrease) in equity from transactions		(75,702)	(82,942)				7,240
Net increase (decrease) in equity		$ (25,791)	(36,266)				10,475
Dividends declared (in usd per share)		$ 1.64
Share conversion	[1]			$ 30	(30)
Net income (loss)		$ 63,177	57,933			57,933	5,244
Stock Issued During Period, Shares, New Issues		8,855,000									8,855,000	[2]
Stock Issued During Period, Value, New Issues	[2]							$ 111,034	$ 111,034	$ 111,034	$ 156,328		$ 156,328	$ 9	$ 156,319
Contributions from non-controlling interests		$ 27,650					27,650
Dividends		59,824									$ 58,499
Dividends	[3]	(59,824)	(58,499)			(58,499)	(1,325)
Dividends, Preferred Stock, Cash	[4]	1,466	1,466			1,466
Distributions to non-controlling interests		$ (23,063)					(23,063)
Adjustment to non-controlling interests			(392)		(392)		392
Stock issued during period, shares, conversion of units				47,167
Stock Issued During Period, Value, Conversion of Units			(812)		(812)		(812)
Repurchase of shares of common stock (in shares)		(50,825)		(50,825)
Repurchase of shares of common stock		$ (782)	(782)		(782)
Share-based long term incentive plan unit awards		$ 475	464		464		11
Ending balance (in shares) at Dec. 31, 2019		38,647,943		38,647,943
Ending balance at Dec. 31, 2019		$ 868,699	$ 829,265	$ 39	$ 821,747	$ (103,555)	$ 39,434
Change In Shareholders' Equity Resulting From Operations [Abstract]
Dividends declared (in usd per share)		$ 1.81
Preferred Stock, Dividends Per Share, Declared		$ 0.45938
Preferred Stock, Value, Outstanding		$ 111,034

[1] See Note 1 for further details on the share conversion.

[2] Net of underwriters' discounts and offering costs.

[3] For the year ended December 31, 2019, dividends totaling $1.81 per share of common stock and convertible unit outstanding, were declared.

[4] For the year ended December 31, 2019, dividends totaling $0.45938 per share of preferred stock were declared.