Contingent Liabilities (Details Textual) (USD $)	Mar. 31, 2014	Dec. 11, 2013
Loss Contingencies [Line Items]
Accrued Environmental Loss liabilities	$ 46,000,000
Loss Contingency, Range of Possible Loss	32,000,000
Customer Refund Liability, Current	118,000,000
Notice of Penalty		99,000
Environmental Protection Agency [Member]
Loss Contingencies [Line Items]
Accrued Environmental Loss liabilities	13,000,000
Former Operations
Loss Contingencies [Line Items]
Accrued Environmental Loss liabilities	26,000,000
Natural gas underground storage facilities
Loss Contingencies [Line Items]
Accrued Environmental Loss liabilities	7,000,000
Gulf Liquids
Loss Contingencies [Line Items]
Estimated Litigation Liability, Current	$ 13,000,000