Schedule of Volume of Activity Futures Contracts (Details) (Eurodollar Future)	6 Months Ended
	Jun. 30, 2014 Contract	Jun. 30, 2013 Contract
Eurodollar Future
Derivatives Fair Value [Line Items]
Number of contracts, Beginning of period	95,327
New positions opened	102,746	12,949
Early settlements	(70,979)
Settlements at maturity	(3,819)
Number of contracts, End of period	123,275	12,949