Commitments and Contingent Liabilities, Operating Leases (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019
Operating Leases [Abstract]
ROU asset carrying value	[1]	$ 332.0
Lease liability carrying value	[2]	348.6
Lease liability, current		$ 27.8
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]		us-gaap:OtherLiabilitiesCurrent
Lease liability, noncurrent		$ 320.8	$ 171.6
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]		us-gaap:OtherLiabilitiesNoncurrent
Increase in ROU asset during the period		$ 121.8
Increase in lease liability during the period		136.6
Storage and Pipeline Facilities [Member]
Operating Leases [Abstract]
ROU asset carrying value	[1]	128.0
Lease liability carrying value	[2]	$ 128.7
Weighted-average remaining term		15 years
Weighted-average discount rate	[3]	4.30%
Transportation Equipment [Member]
Operating Leases [Abstract]
ROU asset carrying value	[1]	$ 33.5
Lease liability carrying value	[2]	$ 35.6
Weighted-average remaining term		3 years
Weighted-average discount rate	[3]	3.50%
Office and Warehouse Space [Member]
Operating Leases [Abstract]
ROU asset carrying value	[1]	$ 170.5
Lease liability carrying value	[2]	$ 184.3
Weighted-average remaining term		16 years
Weighted-average discount rate	[3]	3.20%

[1] ROU asset amounts are a component of “Other assets” on our Consolidated Balance Sheet.

[2] At December 31, 2020, lease liabilities of $27.8 million and $320.8 million were included within “Other current liabilities” and “Other liabilities,” respectively.

[3] The discount rate for each category of assets represents the weighted average incremental borrowing rate adjusted for collateralization (if the implicit rate is not determinable).  In general, the discount rates are based on either (i) information available at the lease commencement date or (ii) January 1, 2019 for leases existing at the adoption date for ASC 842.