Financing arrangements (Debt Issuances) (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2019 |
|
| Debt Instrument [Line Items] | ||
| Commercial paper, maximum borrowing capacity | $ 2,500,000,000 | |
| Commercial paper issued | $ 12,300,000,000 | |
| Commercial paper repaid | 12,300,000,000 | |
| Commercial paper, maximum outstanding | 1,500,000,000 | |
| Notes [Member] | ||
| Debt Instrument [Line Items] | ||
| Aggregate principal amount of notes issued | $ 4,500,000,000 | |
| Notes [Member] | 1.90% notes due 2019 (1.90% 2019 Notes) [Member] | ||
| Debt Instrument [Line Items] | ||
| Interest rate, stated percentage | 1.90% | 1.90% |
| Notes [Member] | 2.20% notes due 2020 (2.20% 2020 Notes) [Member] | ||
| Debt Instrument [Line Items] | ||
| Interest rate, stated percentage | 2.20% | 2.20% |
| Notes [Member] | 2.65% notes due 2022 (2.65% 2022 Notes) [Member] | ||
| Debt Instrument [Line Items] | ||
| Interest rate, stated percentage | 2.65% | 2.65% |
| Notes [Member] | 3.20% notes due 2027 (3.20% 2027 Notes) [Member] | ||
| Debt Instrument [Line Items] | ||
| Interest rate, stated percentage | 3.20% | 3.20% |