Organization (Details)	9 Months Ended	1 Months Ended
Sep. 30, 2014	Nov. 12, 2014 Subsequent Event [Member]
Organization [Abstract]
Annualized flat rate brokerage fee (in hundredths)	4.00%
Annualized general partner administrative fee (in hundredths)		2.00%
Annualized placement agent fee (in hundredths)		2.00%

Annualized general partner administrative fee percentage payable to Ceres Managed Futures LLC, the General Partner, equal to a stated percentage of the Partnership's net assets.

No definition available.

Name:	dwsf_AnnualizedGeneralPartnerAdministrativeFeePercentage
Namespace Prefix:	dwsf_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration