Derivative Instruments - Effect on Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Carrying Amount of Hedged Assets/(Liabilities)	$ 60.1		$ 60.1		$ 44.5
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount of the Hedged Asset/(Liabilities)	8.7		8.7		4.9
Gain (loss) on derivative
Revenue	8,350.9	$ 4,482.7	21,394.2	$ 15,656.2
Cost of revenue	8,153.4	4,268.7	20,821.3	14,969.6
Derivative, Credit Risk Related Contingent Features [Abstract]
Net derivative liability positions with credit contingent features	3.5		3.5		20.0
Collateral posted and held by our counterparties	0.0		0.0		0.0
Maximum additional potential collateral requirements	3.5		3.5		$ 20.0
Revenue
Gain (loss) on derivative
Revenue	8,350.9	4,482.7	21,394.2	15,656.2
Gains (losses) on fair value hedge relationships:
Total amount of income and expense line items excluding the impact of hedges, Revenue	8,371.0	4,485.5	21,433.5	15,618.0
Cost of revenue
Gain (loss) on derivative
Cost of revenue	8,153.4	4,268.7	20,821.3	14,969.6
Gains (losses) on fair value hedge relationships:
Total amount of income and expense line items excluding the impact of hedges, Cost of Revenue	8,279.8	4,204.1	21,073.2	14,847.2
Interest expense and other financing costs, net
Gain (loss) on derivative
Interest expense and other financing costs, net	10.4	9.4	29.2	36.3
Gains (losses) on fair value hedge relationships:
Total amount of income and expense line items excluding the impact of hedges, Interest expense and other financing costs	10.1	9.2	28.2	36.1
Commodity contracts | Revenue
Gains (losses) on fair value hedge relationships:
Hedged item	0.0	0.0	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0	0.0	0.0
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income	(20.2)	(2.8)	(39.3)	38.2
Commodity contracts | Cost of revenue
Gains (losses) on fair value hedge relationships:
Hedged item	3.1	(1.2)	29.7	(15.4)
Derivatives designated as hedging instruments	(4.8)	1.5	(24.5)	15.3
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income	128.2	(65.0)	246.8	(122.3)
Commodity contracts | Interest expense and other financing costs, net
Gains (losses) on fair value hedge relationships:
Hedged item	0.0	0.0	0.0	0.0
Derivatives designated as hedging instruments	0.0	0.0	0.0	0.0
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income	0.0	0.0	0.0	0.0
Interest rate contracts | Revenue
Gains (losses) on fair value hedge relationships:
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income	0.0	0.0	0.0	0.0
Interest rate contracts | Cost of revenue
Gains (losses) on fair value hedge relationships:
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income	0.0	0.0	0.0	0.0
Interest rate contracts | Interest expense and other financing costs, net
Gains (losses) on fair value hedge relationships:
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income	(0.3)	(0.2)	(1.0)	(0.2)
Derivatives designated as hedging instruments
Gains (losses) on fair value hedge relationships:
Amount of gain (loss) recognized in Accumulated other comprehensive income (loss), net of income tax (expense) benefit	71.4	(61.9)	152.6	(77.4)
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income, net of income tax (expense) benefit	79.7	(68.1)	153.1	(84.4)
Derivatives designated as hedging instruments | Commodity contracts | Revenue
Gains (losses) on fair value hedge relationships:
Gain (loss) not recorded in Accumulated other comprehensive income (loss) due to intra-period settlement	(143.0)	97.8	(334.1)	401.1
Amount of gain (loss) recognized in Accumulated other comprehensive income (loss), net of income tax (expense) benefit	53.7	(22.0)	(22.3)	163.6
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income, net of income tax (expense) benefit	(15.5)	(2.8)	(30.1)	38.2
Derivatives designated as hedging instruments | Commodity contracts | Cost of revenue
Gains (losses) on fair value hedge relationships:
Gain (loss) not recorded in Accumulated other comprehensive income (loss) due to intra-period settlement	22.0	(2.5)	37.2	(176.0)
Amount of gain (loss) recognized in Accumulated other comprehensive income (loss), net of income tax (expense) benefit	17.8	(39.8)	172.1	(237.2)
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income, net of income tax (expense) benefit	95.5	(65.0)	183.9	(122.3)
Derivatives designated as hedging instruments | Interest rate contracts | Interest expense and other financing costs, net
Gains (losses) on fair value hedge relationships:
Amount of gain (loss) recognized in Accumulated other comprehensive income (loss), net of income tax (expense) benefit	(0.2)	(0.1)	2.8	(3.8)
Amount of gain (loss) reclassified from Accumulated other comprehensive income (loss) into net income, net of income tax (expense) benefit	(0.3)	(0.2)	(0.7)	(0.2)
Derivatives not designated as hedging instruments
Gains (losses) on fair value hedge relationships:
Derivative Instruments - Non-designated	20.8	3.2	38.7	116.8
Derivatives not designated as hedging instruments | Commodity contracts
Gains (losses) on fair value hedge relationships:
Derivative Instruments - Non-designated	18.3	16.7	34.2	119.6
Derivatives not designated as hedging instruments | Commodity contracts | Revenue
Gains (losses) on fair value hedge relationships:
Derivative Instruments - Non-designated	3.3	44.3	(287.6)	157.6
Derivatives not designated as hedging instruments | Commodity contracts | Cost of revenue
Gains (losses) on fair value hedge relationships:
Derivative Instruments - Non-designated	15.0	(27.7)	321.8	(38.0)
Derivatives not designated as hedging instruments | Foreign currency contracts
Gains (losses) on fair value hedge relationships:
Derivative Instruments - Non-designated	2.4	(13.4)	4.4	(2.8)
Derivatives not designated as hedging instruments | Foreign currency contracts | Revenue
Gains (losses) on fair value hedge relationships:
Derivative Instruments - Non-designated	0.9	(1.7)	1.1	(1.8)
Derivatives not designated as hedging instruments | Foreign currency contracts | Interest expense and other financing costs, net
Gains (losses) on fair value hedge relationships:
Derivative Instruments - Non-designated	$ 1.5	$ (11.7)	$ 3.4	$ (1.0)