Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12069-110248

Name:	us-gaap_GuaranteeObligationsMaximumExposure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Related Party Transactions (Contractual Joint Venture) (Narrative) (Details) - Joint Venture [Member] $ in Millions, $ in Millions	Dec. 31, 2020 USD ($)	Dec. 31, 2020 CAD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 CAD ($)
Canadian Joint Venture [Member]
Related Party Transaction [Line Items]
Proportionately consolidated non-controlled joint venture, ownership percentage	35.00%	35.00%
Performance Guarantees [Member]
Related Party Transaction [Line Items]
Guarantees issued, related party	$ 20.7	$ 26.4	$ 20.3	$ 26.4