Commitments and Contingencies (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Operating lease obligations:
Lease and rental expense included in costs and expenses	$ 25.6	$ 26.2
Litigation matters [Member]
Loss Contingencies [Line Items]
Litigation accruals on an undiscounted basis	4.5		$ 4.5
Litigation matters [Member] | ETP Lawsuit [Member]
Loss Contingencies [Line Items]
Loss contingency, damages awarded	319.4
Loss contingency, total damages sought	535.8
Loss contingency, disgorgement damages sought	150.0
Prejudgment interest	$ 66.4
Post-judgment interest rate	5.00%
Positive Outcome of Litigation [Member]
Gain Contingencies [Line Items]
Counterclaim settlement awarded	$ 0.8