Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions |
Sep. 30, 2020 |
Dec. 31, 2019 |
|---|---|---|
| Current Assets: | ||
| Allowance for uncollectible accounts | $ 123 | $ 13 |
| Allowance for obsolescence | 208 | 82 |
| Noncurrent Assets: | ||
| Accumulated depreciation and amortization | 18,280 | 17,027 |
| Accumulated amortization | $ 880 | $ 873 |
| Stockholders' Equity: | ||
| Common stock, par value (USD per share) | $ 0.0001 | $ 0.0001 |
| Common stock, authorized (shares) | 1,500,000,000 | 1,500,000,000 |
| Common stock, issued (shares) | 647,370,857 | 651,731,443 |
| Treasury stock, at cost (shares) | 9,636,556 | 8,959,730 |