Nonoperating Income (Expense) (Narrative) (Details) $ / shares in Units, € in Millions, $ in Millions			3 Months Ended			12 Months Ended
	Apr. 30, 2020 USD ($) $ / shares	Oct. 24, 2019 USD ($) $ / shares	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2020 EUR (€)	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2020 USD ($) $ / shares	Dec. 31, 2019 USD ($) $ / shares	Dec. 31, 2018 USD ($)
Other nonoperating income, net pension and postretirement benefits						$ 16	$ 12	$ 35
Gains on investments						18
Other income, net						5
Certain product lines, revenues							170
Proceeds from sale of product lines	$ 826					826	0	0
Gain on sale of product lines	455					455	0	0
Gain on sale of product lines, net of tax	$ 305					$ 305
Gain on sale of product lines, net of tax, per diluted common share | $ / shares	$ 0.42					$ 0.42
Payments of debt extinguishment costs		$ 7			$ 7	$ 26	$ 7	$ 0
Payments of debt extinguishment costs, after-tax		$ 5			$ 5
Payments of debt extinguishment costs, per diluted common share | $ / shares		$ 0.01			$ 0.01
Senior notes | 1.7% senior unsecured notes due 2022
Repayments of debt | €				€ 800
Interest rate of debt instrument			1.70%	1.70%	1.70%	1.70%	1.70%
Payments of debt extinguishment costs			$ 26
Payments of debt extinguishment costs, after-tax			$ 20
Payments of debt extinguishment costs, per diluted common share | $ / shares			$ 0.03
Senior notes | Redeemed notes
Repayments of debt			$ 882		$ 882
Senior notes | 2.4% senior unsecured notes due 2020
Repayments of debt		$ 500
Interest rate of debt instrument		2.40%			2.40%		2.40%
Senior notes | 5.0% senior unsecured notes due 2020
Repayments of debt		$ 375
Interest rate of debt instrument		5.00%			5.00%		5.00%
Pension benefit plans | Non-U.S. Pension Benefits
Curtailment and settlement gains (losses) recognized						$ (1)	$ (7)
Settlement loss, net of tax							$ (6)
Settlement loss, per diluted common share | $ / shares							$ (0.01)