Financial Highlights (Net Investment Income Ratio To Average Equity) (Details)		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financial Highlights [Abstract]
Net Investment Income	[1],[2]	3.80%	9.03%	5.14%	9.05%

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

[2] Includes all items of income and expense on an annualized basis