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=118943654&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] - Performance Guarantees [Member] $ in Millions, $ in Millions	Dec. 31, 2019 USD ($)	Dec. 31, 2019 CAD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 CAD ($)
Related Party Transaction [Line Items]
Guarantees issued, related party		$ 26.4		$ 26.4
Canadian Dollars [Member]
Related Party Transaction [Line Items]
Guarantees issued, related party	$ 20.3		$ 19.4