Consolidated Statements of Capital (Parenthetical) (USD $)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Capital
Cash distribution declared, per common unit	$ 1.08	$ 0.55	$ 0.40

Total distributions per unit to each class of partners (i.e., general, limited and preferred partners).

No definition available.

Name:	slgop_PartnersCapitalAccountDistributionsPerUnitDeclared
Namespace Prefix:	slgop_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration