The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

Contingencies (Third-Party Guarantees) (Details) $ in Millions, $ in Millions	Jun. 30, 2022	Mar. 31, 2022 CAD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021	Oct. 17, 2020 CAD ($)	Oct. 17, 2020 USD ($)
Canadian Government
Loss Contingencies [Line Items]
Project contribution from government		$ 27	$ 22		$ 173	$ 131
Philip Morris Investment B.V. \| Medicago Inc.
Loss Contingencies [Line Items]
Ownership percentage	21.00%			23.00%