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
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
Contributions from non-controlling interests		2,165					2,165
Dividends		(25,501)	(25,327)				(174)
Distributions to non-controlling interests		(10,457)					(10,457)
Adjustment to non-controlling interests		$ 0	(35)				35
Repurchase of shares of common stock (in shares)		(1,186,058)
Repurchase of shares of common stock		$ (17,593)	(17,593)
Share-based long term incentive plan unit redemption and distribution		$ 192	191				1
Ending balance (in shares) at Jun. 30, 2018		30,149,880
Ending balance at Jun. 30, 2018		$ 613,275	599,567				13,708
Change In Shareholders' Equity Resulting From Operations [Abstract]
Net investment income		21,234
Net realized gain (loss) on investments, financial derivatives, and foreign currency transactions		11,708
Change in net unrealized gain (loss) on investments, other secured borrowings, financial derivatives, and foreign currency translation		10,566
Net increase in equity resulting from operations		43,508	42,232				1,276
Net increase (decrease) in equity from transactions		(51,194)	(42,764)				(8,430)
Net increase (decrease) in equity		$ (7,686)	(532)				(7,154)
Beginning balance (in shares) at Mar. 31, 2018		30,392,041
Beginning balance at Mar. 31, 2018		$ 609,950	594,474				15,476
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM OPERATIONS
Contributions from non-controlling interests		929					929
Dividends		(12,650)	(12,563)				(87)
Distributions to non-controlling interests		(3,609)					(3,609)
Adjustment to non-controlling interests		$ 0	(8)				8
Repurchase of shares of common stock (in shares)		(242,161)
Repurchase of shares of common stock		$ (3,628)	(3,628)
Share-based long term incentive plan unit redemption and distribution		$ 99	99				0
Ending balance (in shares) at Jun. 30, 2018		30,149,880
Ending balance at Jun. 30, 2018		$ 613,275	599,567				13,708
Change In Shareholders' Equity Resulting From Operations [Abstract]
Net investment income		10,991
Net realized gain (loss) on investments, financial derivatives, and foreign currency transactions		(1,343)
Change in net unrealized gain (loss) on investments, other secured borrowings, financial derivatives, and foreign currency translation		12,536
Net increase in equity resulting from operations		22,184	21,193				991
Net increase (decrease) in equity from transactions		(18,859)	(16,100)				(2,759)
Net increase (decrease) in equity		$ 3,325	5,093				(1,768)
Beginning balance (in shares) at Dec. 31, 2018		29,796,601		29,796,601
Beginning balance at Dec. 31, 2018		$ 595,170	563,833		$ 665,356	$ (101,523)	31,337
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM OPERATIONS
Share conversion	[1]			$ 30	(30)
Net income (loss)		16,488	15,408			15,408	1,080
Contributions from non-controlling interests		2,512					2,512
Dividends	[2]	(16,764)	(16,360)			(16,360)	(404)
Distributions to non-controlling interests		(4,306)					(4,306)
Adjustment to non-controlling interests			(4)		(4)		4
Repurchase of shares of common stock (in shares)				(50,825)
Repurchase of shares of common stock		(782)	(782)		(782)
Share-based long term incentive plan unit awards		$ 116	114		114		2
Ending balance (in shares) at Mar. 31, 2019		29,745,776		29,745,776
Ending balance at Mar. 31, 2019		$ 592,434	562,209	$ 30	664,654	(102,475)	30,225
Beginning balance (in shares) at Dec. 31, 2018		29,796,601		29,796,601
Beginning balance at Dec. 31, 2018		$ 595,170	563,833		665,356	(101,523)	31,337
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM OPERATIONS
Dividends		$ (29,565)
Repurchase of shares of common stock (in shares)		(50,825)
Repurchase of shares of common stock		$ (800)
Ending balance (in shares) at Jun. 30, 2019		29,745,776		29,745,776
Ending balance at Jun. 30, 2019		$ 593,114	562,470	$ 30	664,764	(102,324)	30,644
Beginning balance (in shares) at Mar. 31, 2019		29,745,776		29,745,776
Beginning balance at Mar. 31, 2019		$ 592,434	562,209	$ 30	664,654	(102,475)	30,225
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM OPERATIONS
Net income (loss)		13,656	12,644			12,644	1,012
Contributions from non-controlling interests		4,936					4,936
Dividends	[2]	(12,801)	(12,493)			(12,493)	(308)
Distributions to non-controlling interests		$ (5,225)					(5,225)
Repurchase of shares of common stock (in shares)		0
Share-based long term incentive plan unit awards		$ 114	110		110		4
Ending balance (in shares) at Jun. 30, 2019		29,745,776		29,745,776
Ending balance at Jun. 30, 2019		$ 593,114	$ 562,470	$ 30	$ 664,764	$ (102,324)	$ 30,644

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

[2] For the three- and six-month periods ended June 30, 2019, dividends totaling $0.42 and $0.97 per share of common stock outstanding were declared.