Investments in Equity Securities (Summary of Financial Data in Cronos) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Net revenues	$ 6,304	$ 7,123	$ 6,367	$ 6,359	$ 6,007	$ 6,856	$ 6,619	$ 5,628	$ 26,153	$ 25,110	$ 25,364
Gross profit	3,146	3,717	3,287	2,873	3,084	3,497	3,319	2,811	13,023	12,711	12,254
Earnings from continuing operations									6,890	766	9,341
Net earnings	1,922	(956)	$ 1,938	$ 1,550	(1,814)	(2,602)	$ 1,997	$ 1,121	4,454	(1,298)	6,967
Net earnings attributable to Cronos									(13)	(5)	$ 4
Total current assets	7,117				4,824				7,117	4,824
Current liabilities	9,063				8,174				9,063	8,174
Noncontrolling interests	$ 40				$ 38				40	38
Cronos Group Inc. [Member] | Equity Method Investments [Member]
Schedule of Equity Method Investments [Line Items]
Net revenues									37	21
Gross profit									(31)	10
Earnings from continuing operations									99	1,117
Net earnings									98	1,117
Net earnings attributable to Cronos									$ 100	$ 1,117
Total current assets		1,394				1,575
Long-term assets		525				511
Current liabilities		143				457
Long-term liabilities		12				7
Noncontrolling interests		$ (3)				$ 0