Schedule of Volume of Activity Futures Contracts (Details) (Eurodollar Future)	9 Months Ended
	Sep. 30, 2014 Contract	Sep. 30, 2013 Contract
Eurodollar Future
Derivatives Fair Value [Line Items]
Number of contracts, Beginning of period	95,327
New positions opened	125,547	121,346
Early settlements	(83,444)	(31,103)
Settlements at maturity	(6,298)	(608)
Number of contracts, End of period	131,132	89,635