Stock Plans and Share-Based Compensation - Restricted Stock Grant and Vesting Information (Details) - Restricted Stock - USD ($) $ / shares in Units, $ in Millions |
12 Months Ended | ||
---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 30, 2016 |
|
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
Weighted-average grant date fair value (in dollars per share) | $ 62.60 | $ 48.35 | $ 24.21 |
Fair value of units vested in fiscal year ending (in millions) | $ 9 | $ 8 | $ 14 |