Investments in Unconsolidated Affiliates (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
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated affiliates	$ 2,938.3		$ 2,938.3		$ 2,437.1
Equity in income (loss) of unconsolidated affiliates by business segment [Abstract]
Equity in income of unconsolidated affiliates	72.3	44.0	179.1	126.1
Unamortized excess cost amounts by business segment [Abstract]
Unamortized excess cost amounts	55.8		55.8		58.1
Equity method investment amortization of excess cost	0.7	0.8	2.3	2.5
NGL Pipelines & Services [Member]
Equity in income (loss) of unconsolidated affiliates by business segment [Abstract]
Equity in income of unconsolidated affiliates	11.7	4.1	19.2	11.8
Unamortized excess cost amounts by business segment [Abstract]
Unamortized excess cost amounts	26.8		26.8		27.7
Equity method investment amortization of excess cost	0.2	0.3	0.9	0.9
NGL Pipelines & Services [Member] | Venice Energy Service Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	13.10%		13.10%
Investments in unconsolidated affiliates	26.9		26.9		27.6
NGL Pipelines & Services [Member] | K/D/S Promix, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	50.00%		50.00%
Investments in unconsolidated affiliates	46.1		46.1		45.4
NGL Pipelines & Services [Member] | Baton Rouge Fractionators LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	32.20%		32.20%
Investments in unconsolidated affiliates	19.1		19.1		19.5
NGL Pipelines & Services [Member] | Skelly-Belvieu Pipeline Company, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	50.00%		50.00%
Investments in unconsolidated affiliates	39.7		39.7		40.8
NGL Pipelines & Services [Member] | Texas Express Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	35.00%		35.00%
Investments in unconsolidated affiliates	348.4		348.4		339.9
NGL Pipelines & Services [Member] | Texas Express Gathering LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	45.00%		45.00%
Investments in unconsolidated affiliates	37.8		37.8		37.8
NGL Pipelines & Services [Member] | Front Range Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	33.30%		33.30%
Investments in unconsolidated affiliates	167.8		167.8		134.5
Onshore Natural Gas Pipelines & Services [Member]
Equity in income (loss) of unconsolidated affiliates by business segment [Abstract]
Equity in income of unconsolidated affiliates	0.9	1.0	2.7	2.9
Onshore Natural Gas Pipelines & Services [Member] | White River Hub, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	50.00%		50.00%
Investments in unconsolidated affiliates	23.5		23.5		24.2
Onshore Crude Oil Pipelines & Services [Member]
Equity in income (loss) of unconsolidated affiliates by business segment [Abstract]
Equity in income of unconsolidated affiliates	46.8	34.3	131.7	101.0
Unamortized excess cost amounts by business segment [Abstract]
Unamortized excess cost amounts	17.3		17.3		17.8
Equity method investment amortization of excess cost	0.2	0.1	0.5	0.5
Onshore Crude Oil Pipelines & Services [Member] | Seaway Crude Pipeline Company LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	50.00%		50.00%
Investments in unconsolidated affiliates	1,372.2		1,372.2		940.7
Onshore Crude Oil Pipelines & Services [Member] | Eagle Ford Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	50.00%		50.00%
Investments in unconsolidated affiliates	279.5		279.5		224.5
Offshore Pipelines & Services [Member]
Equity in income (loss) of unconsolidated affiliates by business segment [Abstract]
Equity in income of unconsolidated affiliates	17.1	9.8	35.8	24.9
Unamortized excess cost amounts by business segment [Abstract]
Unamortized excess cost amounts	9.2		9.2		10.0
Equity method investment amortization of excess cost	0.3	0.3	0.8	1.0
Offshore Pipelines & Services [Member] | Poseidon Oil Pipeline Company, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	36.00%		36.00%
Investments in unconsolidated affiliates	34.3		34.3		41.7
Offshore Pipelines & Services [Member] | Cameron Highway Oil Pipeline Company [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	50.00%		50.00%
Investments in unconsolidated affiliates	204.2		204.2		207.7
Offshore Pipelines & Services [Member] | Deepwater Gateway LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	50.00%		50.00%
Investments in unconsolidated affiliates	81.1		81.1		84.5
Offshore Pipelines & Services [Member] | Neptune Pipeline Company, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	25.70%		25.70%
Investments in unconsolidated affiliates	35.4		35.4		38.7
Offshore Pipelines & Services [Member] | Southeast Keathley Canyon Pipeline Company, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	50.00%		50.00%
Investments in unconsolidated affiliates	147.4		147.4		159.2
Petrochemical & Refined Products Services [Member]
Equity in income (loss) of unconsolidated affiliates by business segment [Abstract]
Equity in income of unconsolidated affiliates	(4.2)	(5.2)	(10.3)	(14.5)
Unamortized excess cost amounts by business segment [Abstract]
Unamortized excess cost amounts	2.5		2.5		2.6
Equity method investment amortization of excess cost	0	0.1	0.1	0.1
Petrochemical & Refined Products Services [Member] | Baton Rouge Propylene Concentrator, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	30.00%		30.00%
Investments in unconsolidated affiliates	6.7		6.7		7.6
Petrochemical & Refined Products Services [Member] | Centennial Pipeline LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership Interest (in hundredths)	50.00%		50.00%
Investments in unconsolidated affiliates	65.6		65.6		60.1
Petrochemical & Refined Products Services [Member] | Other Unconsolidated Affiliates [Member]
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated affiliates	$ 2.6		$ 2.6		$ 2.7