Commitments and Contingencies, Liquidity Option Agreement (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Number of units held by limited partner	54,807,352		54,807,352
Liquidity Option Agreement [Abstract]
Liquidity Option Agreement	$ 273.1		$ 273.1		$ 245.1
Change in fair value of Liquidity Option Agreement	6.9	$ 4.3	28.0	$ 15.8
Liquidity Option Agreement [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair value inputs, Assumed long-term debt			$ 2,200.0
Fair value inputs, Interest rate on assumed debt of OTA following option exercise			4.75%
Increase in fair value of liquidity option agreement excluding assumption of debt	211.1		$ 211.1
Fair value inputs, Life of debt assumed after Liquidity option is exercised			30 years
Fair value inputs, federal and state tax rate			38.00%
Cash flow projections discount rate			7.50%
Fair value inputs, weighted-average expected ownership percentage of contributed units at beginning of option period			83.00%
Increase in fair value of liquidity option agreement assuming retention of all units	$ 56.7		$ 56.7
Liquidity Option Agreement [Abstract]
Other Commitments, Description			We entered into a put option agreement (the “Liquidity Option Agreement”) with OTA and Marquard & Bahls (“M&B”) in connection with the Oiltanking acquisition. Under the Liquidity Option Agreement, we granted M&B the option to sell to us 100% of the issued and outstanding capital stock of OTA at any time within a 90-day period commencing on February 1, 2020.
Liquidity Option Agreement [Member] | Maximum [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair value inputs, Expected life of OTA following option exercise			30 years
Fair value inputs, Estimated growth rates in Enterprise earnings before interest, taxes, depreciation and amortization			15.00%
Fair value inputs, OTA ownership interest in Enterprise common units			2.60%
Fair value inputs, Forecasted yield on Enterprise common units			6.60%
Liquidity Option Agreement [Member] | Minimum [Member]
Fair Value Measurements, Recurring, Valuation Techniques [Line Items]
Fair value inputs, Expected life of OTA following option exercise			1 year
Fair value inputs, Estimated growth rates in Enterprise earnings before interest, taxes, depreciation and amortization			2.00%
Fair value inputs, OTA ownership interest in Enterprise common units			1.90%
Fair value inputs, Forecasted yield on Enterprise common units			5.80%