Summary Of Significant Accounting Policies (Additional Information) (Details) (USD $)	12 Months Ended			12 Months Ended
	Dec. 31, 2013	Feb. 29, 2012 Redemption Baskets [Member]	Feb. 29, 2012 Prior to February 29, 2012 [Member] Redemption Baskets [Member]	Dec. 31, 2013 Maximum [Member]
Significant Accounting Policies [Line Items]
Minimum likelihood of tax benefits being recognized upon ultimate settlement	50.00%
Recognized interest income expense and penalties related to unrecognized tax benefits	$ 0
Number of units per basket		50,000	100,000
Cash equivalents maturity period				6 months