Subsequent Events (Details) - Subsequent Event - Marketing Supply and Logistics - US Salt, LLC $ in Millions	1 Months Ended
Oct. 31, 2017 USD ($)
Subsequent Event [Line Items]
Disposal Group, Ownership Interest Prior to Disposal	100.00%
Disposal Group, Including Discontinued Operation, Consideration	$ 225

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

No definition available.

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Period Type:	duration