Equity-based Awards, Restricted Unit Awards (Details) (Restricted Common Unit Awards [Member], USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended															8 Months Ended		12 Months Ended				11 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Enterprise [Member]		Dec. 31, 2011 Enterprise [Member]		Dec. 31, 2010 Enterprise [Member]		Dec. 31, 2012 Enterprise [Member] Minimum [Member]	Dec. 31, 2011 Enterprise [Member] Minimum [Member]	Dec. 31, 2010 Enterprise [Member] Minimum [Member]	Dec. 31, 2012 Enterprise [Member] Maximum [Member]	Dec. 31, 2011 Enterprise [Member] Maximum [Member]	Dec. 31, 2010 Enterprise [Member] Maximum [Member]	Sep. 06, 2011 Duncan Energy Partners [Member]		Dec. 31, 2011 Duncan Energy Partners [Member]		Dec. 31, 2010 Duncan Energy Partners [Member]		Nov. 21, 2010 Holdings [Member]		Dec. 31, 2010 Holdings [Member]
Summary of awards activity, equity instruments other than options [Roll Forward]
Beginning of period (in units)				3,868,216		3,561,614		2,720,882								0		0		0		0		0
Granted (in units)				1,588,738	[1],[2]	1,414,630	[3],[4]	1,393,925	[5],[6]							3,666	[3],[7]			6,348	[5],[8]	3,424	[5],[9]
Vested (in units)				(1,316,603)	[1]	(924,108)	[3]	(383,628)	[5]							(3,666)	[3]			(6,348)	[5]	(3,424)	[5]
Forfeited (in units)				(246,865)		(183,920)		(169,565)
End of period (in units)				3,893,486		3,868,216		3,561,614								0				0		0
Restricted units outstanding, weighted-average grant date fair value [Roll Forward]
Weighted-average grant date fair value per unit, at beginning of period (in dollars per unit)				$ 34.22	[10]	$ 29.78	[10]	$ 27.70	[10]							$ 0	[10]	$ 0	[10]	$ 0	[10]	$ 0	[10]	$ 0	[10]
Granted weighted-average grant date fair value per unit (in dollars per unit)				$ 51.96	[1],[10],[2]	$ 43.66	[10],[3],[4]	$ 32.60	[10],[5],[6]							$ 32.56	[10],[3],[7]			$ 25.26	[10],[5],[8]	$ 41.47	[10],[5],[9]
Vested weighted-average grant date fair value per unit (in dollars per unit)				$ 34.80	[1],[10]	$ 31.54	[10],[3]	$ 25.51	[10],[5]							$ 32.56	[10],[3]			$ 25.26	[10],[5]	$ 41.47	[10],[5]
Forfeited weighted-average grant date fair value per unit (in dollars per unit)				$ 40.43	[10]	$ 34.27	[10]	$ 29.87	[10]
Weighted-average grant date fair value per unit, at end of period (in dollars per unit)				$ 40.87	[10]	$ 34.22	[10]	$ 29.78	[10]							$ 0	[10]			$ 0	[10]	$ 0	[10]
Summary of awards activity, equity instruments other than options, additional disclosures [Abstract]
Aggregate grant date fair value				$ 82.5		$ 61.8		$ 45.4										$ 0.1		$ 0.2				$ 0.1
Grant date market price of common units (in dollars per unit)										$ 51.92	$ 40.54	$ 32	$ 53.54	$ 44.67	$ 43.18			$ 32.56		$ 25.26				$ 41.47
Estimated forfeiture rate (in hundredths)				3.25%		4.60%		4.60%
Equity based awards issued to independent directors of the entities' general partner (in units)				10,038		10,230		6,960										3,666		6,348				3,424
Cash distributions paid to restricted common unit holders	10.5	9.6	8.0
Total intrinsic value of our restricted common unit awards that vested during period	67.0	39.1	13.9
Unrecognized Compensation Expense [Abstract]
Unrecognized compensation cost	$ 58.4			$ 54.2
Recognition period for total unrecognized compensation cost	1 year 11 months

[1] Includes awards granted to the independent directors of the board of directors of Enterprise GP as part of their annual compensation for 2012. A total of 10,038 restricted common unit awards were issued in February 2012 to the independent directors of Enterprise GP, which immediately vested upon issuance.

[2] The aggregate grant date fair value of restricted common unit awards issued during 2012 was $82.5 million based on a grant date market price of our common units ranging from $51.92 to $53.54 per unit. An estimated annual forfeiture rate of 3.25% was applied to these awards.

[3] Includes awards granted to the independent directors of the boards of directors of Enterprise GP and DEP GP as part of their annual compensation for 2011. A total of 10,230 and 3,666 restricted common unit awards were issued in February 2011 to the independent directors of Enterprise GP and DEP GP, respectively, which immediately vested upon issuance.

[4] The aggregate grant date fair value of restricted common unit awards issued during 2011 was $61.8 million based on a grant date market price of our common units ranging from $40.54 to $44.67 per unit. An estimated annual forfeiture rate of 4.6% was applied to these awards.

[5] Includes awards granted to the independent directors of the boards of directors of EPGP, DEP GP and Holdings GP as part of their annual compensation for 2010. A total of 6,960, 6,348 and 3,424 restricted common unit awards were issued in February 2010 to the independent directors of EPGP, DEP GP and Holdings GP, respectively, which immediately vested upon issuance.

[6] The aggregate grant date fair value of restricted common unit awards issued during 2010 was $45.4 million based on grant date market prices of our common units ranging from $32.00 to $43.18 per unit. An estimated annual forfeiture rate of 4.6% was applied to these awards.

[7] The aggregate grant date fair value of restricted common unit awards issued during 2011 denominated in Duncan Energy Partners' common units was $0.1 million based on a grant date market price of Duncan Energy Partners' common units of $32.56 per unit.

[8] The aggregate grant date fair value of restricted common unit awards issued during 2010 denominated in Duncan Energy Partners' common units was $0.2 million based on a grant date market price of Duncan Energy Partners' common units of $25.26 per unit.

[9] The aggregate grant date fair value of restricted common unit awards issued during 2010 denominated in Holdings' units was $0.1 million based on a grant date market price of Holdings' units of $41.47 per unit.

[10] Determined by dividing the aggregate grant date fair value of awards (before an allowance for forfeitures) by the number of awards issued.