Equity and Distributions, Summary of Changes in Outstanding Units (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary of changes in outstanding units [Roll Forward]
Beginning Balance (in units)	2,161,089,479	2,117,588,414	2,012,553,024
Common units issued in connection with ATM program (in units)		21,807,726	87,867,037
Common units issued in connection with DRIP and EUPP (in units)	19,861,951	19,046,019	16,316,534
Common units issued in connection with the vesting of phantom unit awards (in units)	3,479,958	2,485,580	1,761,455
Common units issues in connection with the vesting of restricted common unit awards (in units)		0	0
Forfeiture of restricted common unit awards (in units)		(1,250)	(43,724)
Cancellation of treasury units acquired in connection with the vesting of equity-based awards (in units)	(1,037,522)	(1,027,798)	(1,000,619)
Common units issued in connection with employee compensation (in units)	1,443,586	1,176,103
Common units issued in connection with land acquisition (in units)	1,223,242
Cancellation of treasury units acquired in connection with buyback program (in units)	(1,236,800)
Other (in units)	45,135	14,685	134,707
Ending Balance (in units)	2,184,869,029	2,161,089,479	2,117,588,414
Common Units (Unrestricted) [Member]
Summary of changes in outstanding units [Roll Forward]
Beginning Balance (in units)	2,161,089,479	2,116,906,120	2,010,592,504
Common units issued in connection with ATM program (in units)		21,807,726	87,867,037
Common units issued in connection with DRIP and EUPP (in units)	19,861,951	19,046,019	16,316,534
Common units issued in connection with the vesting of phantom unit awards (in units)	3,479,958	2,485,580	1,761,455
Common units issues in connection with the vesting of restricted common unit awards (in units)		681,044	1,234,502
Forfeiture of restricted common unit awards (in units)		0	0
Cancellation of treasury units acquired in connection with the vesting of equity-based awards (in units)	(1,037,522)	(1,027,798)	(1,000,619)
Common units issued in connection with employee compensation (in units)	1,443,586	1,176,103
Common units issued in connection with land acquisition (in units)	1,223,242
Cancellation of treasury units acquired in connection with buyback program (in units)	(1,236,800)
Other (in units)	45,135	14,685	134,707
Ending Balance (in units)	2,184,869,029	2,161,089,479	2,116,906,120
Restricted Common Units [Member]
Summary of changes in outstanding units [Roll Forward]
Beginning Balance (in units)	0	682,294	1,960,520
Common units issued in connection with ATM program (in units)		0	0
Common units issued in connection with DRIP and EUPP (in units)	0	0	0
Common units issued in connection with the vesting of phantom unit awards (in units)	0	0	0
Common units issues in connection with the vesting of restricted common unit awards (in units)		(681,044)	(1,234,502)
Forfeiture of restricted common unit awards (in units)		(1,250)	(43,724)
Cancellation of treasury units acquired in connection with the vesting of equity-based awards (in units)	0	0	0
Common units issued in connection with employee compensation (in units)	0	0
Common units issued in connection with land acquisition (in units)	0
Cancellation of treasury units acquired in connection with buyback program (in units)	0
Other (in units)	0	0	0
Ending Balance (in units)	0	0	682,294