Equity and Distributions, Issuances of Equity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Registration Statements and Equity Offerings [Line Items]
Common units issued in connection with acquisition of Oiltanking (in units)			36,827,517	54,807,352
Net Cash Proceeds from Sale of Common Units [Abstract]
Net cash proceeds from the issuance of common units	$ 1,073.4	$ 2,542.8	$ 1,188.6
Common units issued in connection with employee compensation (in units)	1,176,103
Common units issued in connection with employee compensation	$ 33.7
Restricted Common Unit Awards [Member]
Treasury Units:
Conversion of restricted units to common units (in units)	681,044
Acquisition of treasury units in connection with vesting of equity-based awards (in units)	229,910
Phantom Unit Awards [Member]
Treasury Units:
Acquisition of treasury units in connection with vesting of equity-based awards (in units)	797,888
Treasury Units [Member]
Treasury Units:
Maximum common units authorized for repurchase under a buy-back program (in units)	4,000,000
Total of common units repurchased under a buy-back program (in units)	2,763,200
Remaining common units available for repurchase (in units)	1,236,800
Total cost of treasury units	$ 29.5
Junior Debt Obligations [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Debt issued under universal shelf registration	1,700.0
Universal Shelf Registration [Member] | Senior Debt Obligations [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Debt issued under universal shelf registration		$ 1,250.0	$ 2,500.0
Universal Shelf Registration [Member] | Junior Debt Obligations [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Debt issued under universal shelf registration	1,700.0
At-the-Market Registration [Member]
Registration Statements and Equity Offerings [Line Items]
Maximum common units authorized for issuance	$ 2,540.0
Net Cash Proceeds from Sale of Common Units [Abstract]
Number of common units issued (in units)	21,807,726	87,867,037	25,520,424
Gross proceeds from the sale of common units	$ 603.1	$ 2,170.0	$ 825.4
Net cash proceeds from the issuance of common units	597.0	$ 2,160.0	$ 817.4
Remaining units available for issuance	$ 2,540.0
At-the-Market Registration [Member] | EPCO and its privately held affiliates [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Number of common units issued (in units)		3,830,256	3,225,057
Gross proceeds from the sale of common units		$ 100.0	$ 100.0
Distribution Reinvestment Plan [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Number of common units issued (in units)	18,541,355	15,809,503	12,413,351
Net cash proceeds from the issuance of common units	$ 462.9	$ 374.0	$ 359.8
Distribution reinvestment plan discount rate	2.50%
Remaining units available for issuance (in units)	80,717,140
Distribution Reinvestment Plan [Member] | Minimum [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Distribution reinvestment plan discount rate range	0.00%
Distribution Reinvestment Plan [Member] | Maximum [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Distribution reinvestment plan discount rate range	5.00%
Distribution Reinvestment Plan [Member] | EPCO and its privately held affiliates [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Number of common units issued (in units)	4,246,498
Gross proceeds from the sale of common units	$ 100.0	100.0	100.0
Net cash proceeds from the issuance of common units	$ 100.0	$ 100.0	$ 100.0
Employee Unit Purchase Plan [Member]
Net Cash Proceeds from Sale of Common Units [Abstract]
Number of common units issued (in units)	504,664	507,031	380,562
Net cash proceeds from the issuance of common units	$ 13.5	$ 12.7	$ 11.4
Remaining units available for issuance (in units)	5,760,811