Accounting Policies - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]	true
Change in Accounting Principle, Accounting Standards Update, Adoption Date	Jan. 01, 2020
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201613Member	us-gaap:AccountingStandardsUpdate201602Member	us-gaap:AccountingStandardsUpdate201409Member
Retained earnings	$ 4,809	$ 6,113
Accounts receivable	1,691	1,941
Deferred income taxes	1,467	1,527
Research and development expenditures	390	430	$ 424
Advertising costs	304	353	345
Maximum cash investments with single counterparty	345
Capital lease obligations	3	36	6
Accrued capital expenditures financed with extended terms	15
Accrued capital expenditures remaining unpaid	224	243	266
Payments for capital expenditures accrued and unpaid in prior year		243	266	$ 265
Restricted net assets	680
Depreciation expense for property, plant and equipment	857	793	776
Total assets	16,506	17,185
Long Term Debt and Finance Leases	5,432	4,753
Total shareholders’ equity	$ 3,259	4,545	$ 5,070	$ 4,850
Lessee, operating lease, option to terminate, term	1 year
Lessee, operating lease, term of contract	12 months
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Payment term	30 days
Operating lease, weighted average remaining lease term	1 year
Lessee, operating lease, renewal term	1 year
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Payment term	90 days
Operating lease, weighted average remaining lease term	50 years
Lessee, operating lease, renewal term	50 years
Accounting Standards Update 2016-13 | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings					$ (12)
Accounts receivable					(15)
Deferred income taxes					$ 3
Accounting Standards Update 2016-09 | Restatement Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total assets		873
Long Term Debt and Finance Leases		14
Total shareholders’ equity		$ (23)