Financial Instruments (Schedule of Carrying Amounts and Estimated Fair Values of Financial Instruments not Recorded at Fair Value) (Details) - USD ($) $ in Millions |
Jun. 30, 2018 |
Dec. 30, 2017 |
|---|---|---|
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Unamortized debt issuance costs | $ 18 | $ 19 |
| 2.125% Convertible Senior Notes due 2026 | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Stated interest rate | 2.125% | |
| Unamortized debt discount | $ 274 | 286 |
| Carrying Amount | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Short-term debt | 223 | 70 |
| Long-term debt, net | 1,170 | 1,324 |
| Estimated Fair Value | Level 2 | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Short-term debt | 227 | 70 |
| Long-term debt, net | $ 2,312 | $ 2,103 |