Discontinued Operations - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions				3 Months Ended		6 Months Ended
	Jan. 01, 2017	Feb. 04, 2013	Dec. 05, 2012	Dec. 30, 2016	Jan. 01, 2016	Dec. 30, 2016	Jan. 01, 2016	Nov. 01, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on sale of discontinued operations						$ 0	$ (21)
Diluted (in dollars per share)				$ 1.40	$ (1.22)	$ 2.68	$ (0.03)
CapRock | Discontinued Operations, Held-for-sale | Critical Networks
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration received on disposal of discontinued operations								$ 425
Loss on sale of discontinued operations				$ 0	$ (21)	$ 0	$ (21)
CapRock | Discontinued Operations, Held-for-sale | Critical Networks | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration received on disposal of discontinued operations	$ 425
CapRock | Discontinued Operations, Disposed of by Sale | Variable Rate Term Loan Agreement | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Repayments of term loans	248
Voluntary principal prepayments of term loans	215
Scheduled repayments of term loans	$ 33
Broadcast Communications | Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash consideration received on disposal of discontinued operations		$ 160
Asset sale agreement			$ 225
Asset sale agreement, promissory note		15
Asset sale agreement, earnout		$ 50
Loss on sale of discontinued operations					(21)
Discontinued operations, net of income taxes					$ (17)
Diluted (in dollars per share)					$ (0.14)