Leases - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Operating lease cost	$ 60.3	$ 176.5
Operating Lease, Right-of-Use Asset	1,011.0	1,011.0	$ 853.9
Operating Lease, Liability, Current	153.8	153.8
Operating Lease, Liability, Noncurrent	$ 842.3	$ 842.3
Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	1 year	1 year
Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	20 years	20 years
Hydrogen Supply [Member]
Lessee, Lease, Description [Line Items]
Lessee, Leases Not Yet Commenced, Liability	$ 212.6	$ 212.6
Lease with Affiliate [Member]
Lessee, Lease, Description [Line Items]
Operating lease cost	32.1	96.1
Operating Lease, Right-of-Use Asset	666.2	666.2	$ 604.4	$ 0.0
Operating Lease, Liability, Current	75.7	75.7		0.0
Operating Lease, Liability, Noncurrent	$ 590.4	$ 590.4		$ 0.0
Lease with Affiliate [Member] | Minimum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	7 years	7 years
Lease with Affiliate [Member] | Maximum [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	15 years	15 years
Hydrogen Supply - Second Quarter 2020 [Member]
Lessee, Lease, Description [Line Items]
Lessee, Lease Not Yet Commenced, Term Of Contract		15 years