Investment in Unconsolidated Affiliate Investment in Unconsolidated Affiliate (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended	3 Months Ended			3 Months Ended		12 Months Ended		3 Months Ended		3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014 Gulf Coast Fractionators	Mar. 31, 2013 Gulf Coast Fractionators	Dec. 31, 2013 Gulf Coast Fractionators	Mar. 31, 2014 Total [Member]	Mar. 31, 2013 Howard Energy Partners	Dec. 31, 2013 Howard Energy Partners	Mar. 31, 2014 Howard Energy Partners	Mar. 31, 2014 Gulf Coast Fractionators	Mar. 07, 2014 Gulf Coast Fractionators	Mar. 31, 2014 Total [Member]
Schedule of Equity Method Investments [Line Items]
Undistributed Earnings, Basic											$ 13.1
Equity Method Investments	271.4		61.1	52.1		61.1			0	219.3
Distribution of earnings from equity investment	0.1	0		0			2.7						2.7
Equity Method Investment, Ownership Percentage				38.75%						30.60%	38.75%	38.75%
Income from equity investment	$ 4.2	$ 1.0	$ 4.2	$ 4.1	$ 1.0			$ 0	$ 0.1