Discontinued Operations Discontinued Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Gulf Coast Fractionators	Mar. 07, 2014 Gulf Coast Fractionators	Mar. 31, 2014 Total [Member]	Mar. 31, 2013 Total [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating revenues	$ 6.8	$ 11.4			$ 17.3	$ 34.5
Operating revenues - affiliates	10.5	23.1
Total operating expenses	15.7	24.4
Income before income taxes	1.6	10.1
Income tax expense	0.6	3.6
Net income	1.0	6.5
Net income attributable to non-controlling interest	0	(0.6)
Net income including non-controlling interest	1.0	5.9
Equity Method Investment, Ownership Percentage			38.75%	38.75%
Inventories	0.2
Other current assets	0.2
Total current assets	0.4
Property, plant & equipment	72.3
Total assets	72.7
Accounts Payable	3.2
Other current liabilities	1.1
Total current liabilities	4.3
Asset Retirement Obligation	7.1
Deferred income taxes	25.3
Other long-term liabilities	0.3
Total liabilities	$ 37.0