Investments in Equity Securities (Investment in Cronos Narrative) (Details) - Cronos Group Inc. [Member] $ / shares in Units, shares in Millions, $ in Billions				3 Months Ended		9 Months Ended
	Mar. 31, 2019 USD ($) shares	Mar. 31, 2019 CAD ($)	Mar. 07, 2019 CAD ($)	Mar. 31, 2020 USD ($) director board_member shares	Mar. 31, 2020 CAD ($)	Sep. 30, 2019	Dec. 31, 2019 USD ($)	Mar. 31, 2019 $ / shares
Investments [Line Items]
Number of ordinary shares owned (approximately) (in shares) | shares	149.8
Ownership percentage (approximately)	45.00%			45.00%
Equity method investments, purchase price	$ 1,800,000,000	$ 2.4	$ 2.4
Equity method investment, warrant exercised, ownership percentage (approximately)	55.00%	55.00%
Payments to acquire equity method investments	$ 400,000,000
Payments for deferred tax liability	300,000,000
Number of directors nominated | director				4
Equity method investment, number of independent directors nominated | director				1
Number of members on the Board of Directors | board_member				7
Equity method investments				$ 1,203,000,000			$ 1,305,000,000
Equity method investment, difference between carrying amount and fair value, percentage (approximately)						(14.00%)
Equity Contract, Preemptive Rights [Member]
Investments [Line Items]
Equity method investment, shares purchased, (CAD per share) | $ / shares								$ 16.25
Equity method investment, number of shares eligible for purchase (in shares) | shares				37.0
Payments for derivative instrument, investing activities	$ 500,000,000
Equity method investment, aggregate exercise price				$ 400,000,000	$ 0.6
Equity Contract, Warrant [Member]
Investments [Line Items]
Equity method investment, shares purchased, (CAD per share) | $ / shares								$ 19.00
Equity method investment, number of shares eligible for purchase (in shares) | shares				78.0
Equity method investment, percentage of shares eligible for purchase	10.00%
Payments for derivative instrument, investing activities	$ 1,200,000,000
Equity method investment, aggregate exercise price				$ 1,100,000,000	$ 1.5
Common Stock [Member]
Investments [Line Items]
Equity method investments				1,037,000,000			1,002,000,000
Equity method investment, impairment				0
Fair Value, Inputs, Level 1 [Member]
Investments [Line Items]
Fair value of equity investment				$ 900,000,000			$ 1,200,000,000