Equity and Distributions, Summary of Changes in Outstanding Units (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Common Units (Unrestricted) [Member]
Summary of changes in outstanding units [Roll Forward]
Beginning Balance (in units)	1,933,095,027	1,864,148,802	1,789,839,702
Common units issued in connection with underwritten offerings (in units)			36,800,000
Common units issued in connection with ATM program (in units)	25,520,424	1,590,334	15,249,378
Common units issued in connection with DRIP and EUPP (in units)	12,793,913	9,754,227	10,308,254
Common units issued in connection with Oiltanking acquisition (in units)	36,827,517	54,807,352
Common units issued in connection with the vesting and exercise of unit options (in units)	396,158	1,014,108	401,764
Common units issued in connection with the vesting of phantom unit awards (in units)	618,395	23,311
Common units issued in connection with the vesting of restricted common unit awards (in units)	2,009,970	2,634,074	3,770,696
Conversion and reclassification of Class B units to common units (in units)			9,040,862
Restricted common units awards issued (in units)			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)	(683,954)	(894,383)	(1,261,854)
Other (in units)	15,054	17,202
Ending Balance (in units)	2,010,592,504	1,933,095,027	1,864,148,802
Restricted Common Units [Member]
Summary of changes in outstanding units [Roll Forward]
Beginning Balance (in units)	4,229,790	7,221,214	7,786,972
Common units issued in connection with underwritten offerings (in units)			0
Common units issued in connection with ATM 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 Oiltanking acquisition (in units)	0	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	0
Common units issued in connection with the vesting of restricted common unit awards (in units)	(2,009,970)	(2,634,074)	(3,770,696)
Conversion and reclassification of Class B units to common units (in units)			0
Restricted common units awards issued (in units)			3,549,052
Forfeiture of restricted common unit awards (in units)	(259,300)	(357,350)	(344,114)
Acquisition and cancellation of treasury units in connection with the vesting of equity-based awards (in units)	0	0	0
Other (in units)	0	0
Ending Balance (in units)	1,960,520	4,229,790	7,221,214
Common units [Member]
Summary of changes in outstanding units [Roll Forward]
Beginning Balance (in units)	1,937,324,817	1,871,370,016	1,797,626,674
Common units issued in connection with underwritten offerings (in units)			36,800,000
Common units issued in connection with ATM program (in units)	25,520,424	1,590,334	15,249,378
Common units issued in connection with DRIP and EUPP (in units)	12,793,913	9,754,227	10,308,254
Common units issued in connection with Oiltanking acquisition (in units)	36,827,517	54,807,352
Common units issued in connection with the vesting and exercise of unit options (in units)	396,158	1,014,108	401,764
Common units issued in connection with the vesting of phantom unit awards (in units)	618,395	23,311
Common units issued in connection with the vesting of restricted common unit awards (in units)	0	0	0
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
Forfeiture of restricted common unit awards (in units)	(259,300)	(357,350)	(344,114)
Acquisition and cancellation of treasury units in connection with the vesting of equity-based awards (in units)	(683,954)	(894,383)	(1,261,854)
Other (in units)	15,054	17,202
Ending Balance (in units)	2,012,553,024	1,937,324,817	1,871,370,016