Financial Highlights (Net Investment Income Ratio To Average Equity) (Details)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Financial Highlights [Abstract]
Net Investment Income	8.62%	[1],[2]	8.40%	[1],[2]	5.59%	[1],[2]

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

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