Debt and Secured Revolving Line of Credit (Interest Expense Recognized) (Details) - 2.125% Convertible Senior Notes due 2026 - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2018 |
Jul. 01, 2017 |
Jun. 30, 2018 |
Jul. 01, 2017 |
|
| Debt Instrument [Line Items] | ||||
| Contractual interest expense | $ 4 | $ 5 | $ 9 | $ 9 |
| Interest cost related to amortization of debt issuance costs | 0 | 0 | 1 | 1 |
| Interest cost related to amortization of the debt discount | $ 6 | $ 5 | $ 12 | $ 11 |
| X | ||||||||||
- Definition Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Definition Amount of amortization expense attributable to debt issuance costs. Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition Represents the portion of interest incurred in the period on debt arrangements that was charged against earnings, excluding amortization of debt discount (premium) and financing costs. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|