Leases - Lease Assets and Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Lease Assets and Liabilities [Line Items]
Operating Lease, Right-of-Use Asset	$ 933.7	$ 853.9
Finance Lease, Right-of-Use Asset	14.2
Operating Lease, Liability, Current	152.6
Finance Lease, Liability, Current	1.1
Operating Lease, Liability, Noncurrent	766.4
Finance Lease, Liability, Noncurrent	13.3
Operating Lease, Liability	933.4
Third Party Lease [Member]
Lease Assets and Liabilities [Line Items]
Operating Lease, Right-of-Use Asset	236.5		$ 0.0
Operating Lease, Liability, Current	80.1		0.0
Operating Lease, Liability, Noncurrent	155.9		0.0
Lease with Affiliate [Member]
Lease Assets and Liabilities [Line Items]
Operating Lease, Right-of-Use Asset	683.0	$ 604.4	0.0
Operating Lease, Liability, Current	72.5		0.0
Operating Lease, Liability, Noncurrent	$ 610.5		$ 0.0