Financial Highlights (Net Investment Income Ratio To Average Equity) (Details)		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Financial Highlights [Abstract]
Net Investment Income	[1],[2],[3]	9.03%	8.02%	9.05%	8.27%

[1] Average equity is calculated using month end values.

[2] Includes all items of income and expense on an annualized basis except for incentive fee expense which is included on a non-annualized basis.

[3] Includes incentive fee in calculation which can vary substantially over periods.