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		1,236					1,236
Dividends		(12,850)	(12,763)				(87)
Distributions to non-controlling interests		(6,848)					(6,848)
Adjustment to non-controlling interests		$ 0	(27)				27
Repurchase of shares of common stock (in shares)		(943,897)
Repurchase of shares of common stock		$ (13,966)	(13,966)
Share-based long term incentive plan unit redemption and distribution		$ 93	92				1
Ending balance (in shares) at Mar. 31, 2018		30,392,041
Ending balance at Mar. 31, 2018		$ 609,950	594,474				15,476
Change In Shareholders' Equity Resulting From Operations [Abstract]
Net investment income		10,242
Net realized gain (loss) on investments, financial derivatives, and foreign currency transactions		13,051
Change in net unrealized gain (loss) on investments, other secured borrowings, financial derivatives, and foreign currency translation		(1,969)
Net increase in equity resulting from operations		21,324	21,039				285
Net increase (decrease) in equity from transactions		(32,335)	(26,664)				(5,671)
Net increase (decrease) in equity		$ (11,011)	(5,625)				(5,386)
Beginning balance (in shares) at Dec. 31, 2018		29,796,601		29,796,601,000
Beginning balance at Dec. 31, 2018		$ 595,170	563,833	$ 0	$ 665,356	$ (101,523)	31,337
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM OPERATIONS
Share conversion	[1]	0		$ 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		$ 0	(4)		(4)		4
Repurchase of shares of common stock (in shares)		(50,825)		(50,825,000)
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		29,745,776,000
Ending balance at Mar. 31, 2019		$ 592,434	$ 562,209	$ 30	$ 664,654	$ (102,475)	$ 30,225

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

[2] For the three-month period ended March 31, 2019, dividends totaling $0.55 per share of common stock outstanding were declared.