Significant Accounting Policies (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
	Jan. 01, 2018	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Dec. 31, 2017
Assets:
Inventory, net	$ 455	$ 493		$ 493		$ 458
Prepaid expenses and other current assets	31	51		51		24
Long-term deferred income taxes	114	91		91		119
Other long-term assets	77	101		101		65
Liabilities:
Deferred revenue	184
Long-term deferred revenue	142
Stockholders’ Equity:
Retained earnings	1,267	1,573		1,573		1,248
Increase in liability related to changes in revenue recognition	1
Impact on revenue before new revenue recognition guidance		1,092	$ 935	3,081	$ 2,696
Calculated under Revenue Guidance in Effect before Topic 606
Assets:
Inventory, net						458
Prepaid expenses and other current assets						24
Long-term deferred income taxes						119
Other long-term assets						65
Liabilities:
Deferred revenue						186
Long-term deferred revenue						148
Stockholders’ Equity:
Retained earnings						$ 1,248
ASU 2014-09 | Calculated under Revenue Guidance in Effect before Topic 606
Stockholders’ Equity:
Impact on revenue before new revenue recognition guidance		$ (1)		$ (3)
ASU 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Assets:
Inventory, net	(3)
Prepaid expenses and other current assets	7
Long-term deferred income taxes	(5)
Other long-term assets	12
Liabilities:
Deferred revenue	(2)
Long-term deferred revenue	(6)
Stockholders’ Equity:
Retained earnings	19
Adjustment related to reallocation of revenue between performance obligations	$ (3)