Valuation and Qualifying Accounts (Schedule of Valuation and Qualifying Accounts) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for Doubtful Accounts
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period		$ 32	$ 36	$ 38
Charged to Costs and Expenses		3	2	15
Charged to Other Accounts	[1]	1	(1)	(3)
Deductions	[2]	2	5	14
Balance at End of Period		34	32	36
Allowances for Sales Discounts
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period		17	17	18
Charged to Costs and Expenses		240	249	248
Charged to Other Accounts	[1]	(3)	(4)	(4)
Deductions	[3]	238	245	245
Balance at End of Period		16	17	17
Deferred Taxes
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period		248	220	176
Charged to Costs and Expenses		21	26	55
Charged to Other Accounts		0	0	0
Deductions	[4]	(3)	(2)	11
Balance at End of Period		$ 272	$ 248	$ 220

[1] Includes bad debt recoveries and the effects of changes in foreign currency exchange rates.

[2] Primarily uncollectible receivables written off.

[3] Sales discounts allowed.

[4] Represents the net currency effects of translating valuation allowances at current rates of exchange.