XML 151 R152.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Supplemental Financial Statement Data Allowance for doubtful accounts (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 28, 2019
Dec. 29, 2018
Dec. 30, 2017
Supplemental Financial Statement Data [Abstract]      
Balance at beginning of year $ 10 $ 10 $ 8
Additions charged to expense 9 4 14
Doubtful accounts charged to reserve (9) (4) (12)
Balance at end of year $ 10 $ 10 $ 10