Equity and Distributions (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended							12 Months Ended				12 Months Ended			12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Common units [Member]	Dec. 31, 2011 Common units [Member]	Dec. 31, 2010 Common units [Member]	Dec. 31, 2012 Class B units [Member]	Dec. 31, 2011 Class B units [Member]	Dec. 31, 2012 Treasury Units [Member]	Dec. 31, 2010 Holdings Merger [Member]	Dec. 31, 2010 Holdings Merger [Member] Common units [Member]	Nov. 21, 2010 Holdings Merger [Member] Common units [Member]	Dec. 31, 2011 Duncan Merger [Member]	Dec. 31, 2011 Duncan Merger [Member] Common units [Member]	Sep. 06, 2011 Duncan Merger [Member] Common units [Member]	Dec. 31, 2009 TEPPCO Merger [Member] Class B units [Member]
Mergers [Line Items]
Units outstanding (in units)			898,813,337	881,620,418		4,520,431	4,520,431				139,195,064			24,036,950
Common unit exchange ratio in connection with merger									1.5	1.5		1.01	1.01		1.24
Common units issued in connection with merger (in units)										208,813,454			24,277,310		4,520,431
Common units cancelled immediately after merger (in units)					21,563,177					21,563,177
Equity transferred pursuant to Holdings Merger		$ 0							$ 8,880.0
Equity transferred pursuant to Duncan Merger	0											401.7
Number of quarters Class B units are not entitled to regular quarterly cash distributions															16
Treasury Units [Abstract]
Maximum common units authorized for repurchase under a buy-back program (in units)								2,000,000
Maximum remaining common units authorized for repurchase under a buy-back program (in units)								618,400
Conversion of restricted units and similar awards to common units (in units)			1,356,204
Acquisition of treasury units in connection with vesting of equity-based awards (in units)			(408,241)	(255,276)	(103,241)			408,241
Total cost of treasury units								$ 20.9