Contingencies (Details) (USD $) In Thousands, unless otherwise specified			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Enogex Federal Court Case [Member]	Dec. 31, 2013 Enogex State Court Case [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value			$ 75,000	$ 105,000
Accrued environmental	$ 3,871	$ 4,586
Number of years expected for future environmental remediation expenditures	14 years