Discontinued Operations (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Sep. 30, 2014 Gulf Coast Fractionators	Mar. 07, 2014 Gulf Coast Fractionators
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Revenue, External		$ 10.9	$ 6.8	$ 33.5
Disposal Group, Including Discontinued Operation, Revenue, Related Party		20.8	10.5	68.1
Operating revenues		31.7	17.3	101.6
Total operating expenses		37.9	15.7	91.7
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax		(6.2)	1.6	9.9
Income tax expense		(2.2)	0.6	3.6
Income (loss) from discontinued operations, net of tax	0	(4.0)	1.0	6.3
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest	0	(0.3)	0	(1.4)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	0	(4.3)	1.0	4.9
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	0		0		72.7
Accounts Payable					3.2
Other current liabilities					1.1
Liabilities Of Disposal Group Including Discontinued Operations					4.3
Liabilities held for disposition	0		0		37.0
Asset Retirement Obligation					7.1
Deferred income taxes					25.3
Other long-term liabilities					$ 0.3