Equity and Distributions, Summary of Changes in Outstanding Units (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Common Units (Unrestricted) [Member]
Summary of changes in outstanding units [Roll Forward]
Beginning Balance (in units)	1,864,148,802	1,789,839,702	1,755,504,404
Common units issued in connection with underwritten offerings (in units)		36,800,000	18,400,000
Common units issued in connection with at-the-market program (in units)	1,590,334	15,249,378	7,957,090
Common units issued in connection with DRIP and EUPP (in units)	9,754,227	10,308,254	5,629,320
Common units issued in connection with Step 1 of Oiltanking acquisition (in units)	54,807,352
Common units issued in connection with the vesting and exercise of unit options (in units)	1,014,108	401,764	427,828
Common units issued in connection with the vesting of phantom unit awards (in units)	23,311
Common units issued in connection with the vesting of restricted common unit awards (in units)	2,634,074	3,770,696	2,633,206
Common units issued in connection with the vesting of other types of equity-based awards (in units)			104,336
Conversion and reclassification of Class B units to common units (in units)		9,040,862
Restricted common units awards issued (in units)		0	0
Forfeiture of restricted common unit awards (in units)	0	0	0
Acquisition and cancellation of treasury units in connection with the vesting of equity-based awards (in units)	(894,383)	(1,261,854)	(816,482)
Other (in units)	17,202
Ending Balance (in units)	1,933,095,027	1,864,148,802	1,789,839,702
Restricted Common Units [Member]
Summary of changes in outstanding units [Roll Forward]
Beginning Balance (in units)	7,221,214	7,786,972	7,736,432
Common units issued in connection with underwritten offerings (in units)		0	0
Common units issued in connection with at-the-market program (in units)	0	0	0
Common units issued in connection with DRIP and EUPP (in units)	0	0	0
Common units issued in connection with Step 1 of Oiltanking acquisition (in units)	0
Common units issued in connection with the vesting and exercise of unit options (in units)	0	0	0
Common units issued in connection with the vesting of phantom unit awards (in units)	0
Common units issued in connection with the vesting of restricted common unit awards (in units)	(2,634,074)	(3,770,696)	(2,633,206)
Common units issued in connection with the vesting of other types of equity-based awards (in units)			0
Conversion and reclassification of Class B units to common units (in units)		0
Restricted common units awards issued (in units)		3,549,052	3,177,476
Forfeiture of restricted common unit awards (in units)	(357,350)	(344,114)	(493,730)
Acquisition and cancellation of treasury units in connection with the vesting of equity-based awards (in units)	0	0	0
Other (in units)	0
Ending Balance (in units)	4,229,790	7,221,214	7,786,972
Common units [Member]
Summary of changes in outstanding units [Roll Forward]
Beginning Balance (in units)	1,871,370,016	1,797,626,674	1,763,240,836
Common units issued in connection with underwritten offerings (in units)		36,800,000	18,400,000
Common units issued in connection with at-the-market program (in units)	1,590,334	15,249,378	7,957,090
Common units issued in connection with DRIP and EUPP (in units)	9,754,227	10,308,254	5,629,320
Common units issued in connection with Step 1 of Oiltanking acquisition (in units)	54,807,352
Common units issued in connection with the vesting and exercise of unit options (in units)	1,014,108	401,764	427,828
Common units issued in connection with the vesting of phantom unit awards (in units)	23,311
Common units issued in connection with the vesting of restricted common unit awards (in units)	0	0	0
Common units issued in connection with the vesting of other types of equity-based awards (in units)			104,336
Conversion and reclassification of Class B units to common units (in units)		9,040,862
Restricted common units awards issued (in units)		3,549,052	3,177,476
Forfeiture of restricted common unit awards (in units)	(357,350)	(344,114)	(493,730)
Acquisition and cancellation of treasury units in connection with the vesting of equity-based awards (in units)	(894,383)	(1,261,854)	(816,482)
Other (in units)	17,202
Ending Balance (in units)	1,937,324,817	1,871,370,016	1,797,626,674