Derivatives - Balance Sheet Location (Details) - USD ($) $ in Millions	Sep. 30, 2018	Dec. 31, 2017
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	$ 559.1	$ 312.0
Derivative liabilities	581.6	332.5
Derivatives designated as hedging instruments
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	56.9	2.7
Derivative liabilities	93.7	43.6
Derivatives designated as hedging instruments | Commodity contracts
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	56.9	2.7
Derivative liabilities	93.3	43.6
Derivatives designated as hedging instruments | Commodity contracts | Short-term derivative assets, net
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	56.9	0.4
Derivative liabilities	93.3	0.5
Derivatives designated as hedging instruments | Commodity contracts | Accrued expenses and other current liabilities
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	0.0	2.3
Derivative liabilities	0.0	43.1
Derivatives designated as hedging instruments | Foreign currency contracts
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	0.1	0.0
Derivative liabilities	0.4	0.0
Derivatives designated as hedging instruments | Foreign currency contracts | Short-term derivative assets, net
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	0.0	0.0
Derivative liabilities	0.4	0.0
Derivatives designated as hedging instruments | Foreign currency contracts | Accrued expenses and other current liabilities
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	0.1	0.0
Derivative liabilities	0.0	0.0
Derivatives not designated as hedging instruments
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	502.2	309.4
Derivative liabilities	488.0	288.9
Derivatives not designated as hedging instruments | Commodity contracts
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	499.9	300.9
Derivative liabilities	485.7	280.2
Derivatives not designated as hedging instruments | Commodity contracts | Short-term derivative assets, net
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	322.8	191.4
Derivative liabilities	225.8	123.3
Derivatives not designated as hedging instruments | Commodity contracts | Identifiable intangible and other non-current assets
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	76.1	18.2
Derivative liabilities	49.9	5.2
Derivatives not designated as hedging instruments | Commodity contracts | Accrued expenses and other current liabilities
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	89.8	86.1
Derivative liabilities	179.0	138.2
Derivatives not designated as hedging instruments | Commodity contracts | Other long-term liabilities
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	11.2	5.2
Derivative liabilities	31.0	13.5
Derivatives not designated as hedging instruments | Foreign currency contracts
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	2.3	8.5
Derivative liabilities	2.3	8.7
Derivatives not designated as hedging instruments | Foreign currency contracts | Short-term derivative assets, net
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	1.8	4.5
Derivative liabilities	0.3	2.8
Derivatives not designated as hedging instruments | Foreign currency contracts | Accrued expenses and other current liabilities
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	0.5	3.9
Derivative liabilities	2.0	5.7
Derivatives not designated as hedging instruments | Foreign currency contracts | Other long-term liabilities
Information about derivative instruments measured at fair value and their locations on the consolidated balance sheet
Derivative assets	0.0	0.0
Derivative liabilities	$ 0.0	$ 0.2