Property, Plant and Equipment, Other (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Property, Plant and Equipment [Line Items]
Capital expenditures	$ 3,025.1	$ 3,830.7	$ 2,892.9
Loss due to Pascagoula fire	7.1
Proceeds from disposal of assets	$ 46.5	1,608.6	$ 145.3
Offshore Pipelines And Services [Member]
Property, Plant and Equipment [Line Items]
Percentage of segment assets			0.043
Percentage of gross operating margin			0.031
Pascagoula Natural Gas Processing Facility [Member]
Property, Plant and Equipment [Line Items]
Undivided ownership interest acquired	60.00%
Capital expenditures	$ 35.0
Loss due to Pascagoula fire	7.1
Fire response expenses	$ 10.4
Offshore Business [Member]
Property, Plant and Equipment [Line Items]
Description of assets sold	Our Offshore Business served drilling and development regions, including deepwater production fields, in the northern Gulf of Mexico offshore Alabama, Louisiana, Mississippi and Texas and included approximately 2,350 miles of offshore natural gas and crude oil pipelines and six offshore hub platforms.
Proceeds from disposal of assets	$ 0.0	$ 1,527.7	$ 0.0