Discontinued Operations - Depreciation, Amortization, Capital Expenditures, and Significant Operating and Investing Noncash Items (Details) - Critical Networks - CapRock - Discontinued Operations, Held-for-sale - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Dec. 30, 2016	Jan. 01, 2016	Dec. 30, 2016	Jan. 01, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation and amortization	$ 3	$ 12	$ 11	$ 25
Capital expenditures	2	4	4	8
Impairment of goodwill and other assets	$ 0	$ 367	$ 0	$ 367