Financial Highlights (Net Investment Income Ratio To Average Equity) (Details)		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Financial Highlights [Abstract]
Net Investment Income	[1],[2]	8.99%	8.27%	9.00%	8.67%

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

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