Financial Highlights (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financial Highlights [Abstract]
Minimum rate of return	1.55%	3.88%	3.03%	6.17%
Maximum rate of return	1.78%	4.11%	3.73%	6.88%