Leases - Lease Assets and Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Lease Assets and Liabilities [Line Items]
Operating Lease, Right-of-Use Asset	$ 1,011.0	$ 853.9
Finance Lease, Right-of-Use Asset	13.8
Operating Lease, Liability, Current	153.8
Finance Lease, Liability, Current	1.1
Operating Lease, Liability, Noncurrent	842.3
Finance Lease, Liability, Noncurrent	13.1
Operating Lease, Liability	1,010.3
Third Party Lease [Member]
Lease Assets and Liabilities [Line Items]
Operating Lease, Right-of-Use Asset	331.0		$ 0.0
Operating Lease, Liability, Current	78.1		0.0
Operating Lease, Liability, Noncurrent	251.9		0.0
Lease with Affiliate [Member]
Lease Assets and Liabilities [Line Items]
Operating Lease, Right-of-Use Asset	666.2	$ 604.4	0.0
Operating Lease, Liability, Current	75.7		0.0
Operating Lease, Liability, Noncurrent	$ 590.4		$ 0.0