Summary of Significant Accounting Policies - Additional Information (Detail) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jul. 01, 2017 USD ($)	Jun. 30, 2018 USD ($) Segment	Jul. 01, 2017 USD ($)	Dec. 30, 2017 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments | Segment			3
Assets related to discontinued operation	$ 0		$ 0		$ 139
Liabilities related to discontinued operation	0		0		67
Accounts payable and accrued expenses and other current liabilities not yet presented for payment	51		51		53
Cash and cash equivalents	747		747		$ 622
Cumulative effect on accumulated deficit, net of tax			4
Reduction in sales from service	(11)		(38)
Reduction in cost of service	(11)		(38)
Selling, general and administrative expenses	(534)	$ (483)	(1,107)	$ (1,014)
Other income, net	5	2	6	6
Accounting Standards Update 2014-09
Summary Of Significant Accounting Policies [Line Items]
Cumulative effect on accumulated deficit, net of tax			(4)
Accounting Standards Update 2017-07 | Adjustment
Summary Of Significant Accounting Policies [Line Items]
Selling, general and administrative expenses		(5)		(8)
Other income, net		$ 5		$ 8
Prepaid Expenses and Other Current Assets
Summary Of Significant Accounting Policies [Line Items]
Restricted cash, included in Prepaid expenses and other current assets	3		3
Non-US
Summary Of Significant Accounting Policies [Line Items]
Cash and cash equivalents	$ 219		$ 219
CompuCom
Summary Of Significant Accounting Policies [Line Items]
Percentage of revenue exceeding current revenue due to acquisition	10.00%		10.00%