Consolidated Statement Of Changes In Equity (USD $) In Thousands, unless otherwise specified		Total		Parent [Member]	Noncontrolling Interest [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2013		$ 626,049
Stockholders' Equity Attributable to Noncontrolling Interest at Dec. 31, 2013					5,648
Stockholders' Equity Attributable to Parent at Dec. 31, 2013				620,401
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM OPERATIONS
Net investment income	[1]	14,081
Net realized gain (loss) on investments, financial derivatives, and foreign currency transactions	[1]	11,408
Change in net unrealized gain (loss) on investments, financial derivatives, and foreign currency translation	[1]	(2,651)
Net Income (Loss) Attributable to Parent		22,635	[1]	22,635
Net Income (Loss) Attributable to Noncontrolling Interest		203	[1]		203
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	[1]	22,838
CHANGE IN EQUITY RESULTING FROM TRANSACTIONS
Shares issued in connection with incentive fee payment		309		309
Contributions from non-controlling interests		1,001			1,001
Dividends	[2]	(20,070)	[3]	(19,907)	(163)
Distributions to non-controlling interest		(114)			(114)
Adjustment to non-controlling interest		0		(497)	497
Share-based LTIP awards		63		62	1
Net increase (decrease) in equity from transactions		(18,811)		(20,033)	1,222
Net increase (decrease) in equity		4,027		2,602	1,425
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Mar. 31, 2014		630,076
Stockholders' Equity Attributable to Noncontrolling Interest at Mar. 31, 2014					7,073
Stockholders' Equity Attributable to Parent at Mar. 31, 2014				623,003
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Dec. 31, 2014		788,544
Stockholders' Equity Attributable to Noncontrolling Interest at Dec. 31, 2014		6,389			6,389
Stockholders' Equity Attributable to Parent at Dec. 31, 2014		782,155		782,155
CHANGE IN SHAREHOLDERS’ EQUITY RESULTING FROM OPERATIONS
Net investment income		17,467
Net realized gain (loss) on investments, financial derivatives, and foreign currency transactions		10,429
Change in net unrealized gain (loss) on investments, financial derivatives, and foreign currency translation		(8,479)
Net Income (Loss) Attributable to Parent		19,261		19,261
Net Income (Loss) Attributable to Noncontrolling Interest		156			156
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		19,417
CHANGE IN EQUITY RESULTING FROM TRANSACTIONS
Shares issued in connection with incentive fee payment		0		0
Contributions from non-controlling interests		500			500
Dividends	[2]	(22,159)	[3]	(22,022)	(137)
Distributions to non-controlling interest		(976)			(976)
Adjustment to non-controlling interest		0		0	0
Share-based LTIP awards		98		97	1
Net increase (decrease) in equity from transactions		(22,537)		(21,925)	(612)
Net increase (decrease) in equity		(3,120)		(2,664)	(456)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest at Mar. 31, 2015		785,424
Stockholders' Equity Attributable to Noncontrolling Interest at Mar. 31, 2015		5,933			5,933
Stockholders' Equity Attributable to Parent at Mar. 31, 2015		$ 779,491		$ 779,491

[1] Conformed to current period presentation.

[2] For the three month periods ended March 31, 2015 and 2014, dividends totaling $0.65 and $0.77, respectively, per common share and convertible unit outstanding, were declared and paid.

[3] The Company pays quarterly dividends in arrears, so a portion of the dividends paid in each calendar year relate to the prior year's earnings.