Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2017	Jul. 01, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Foreign currency translation, net of income taxes of $18 million and $29 million at March 31, 2017 and July 1, 2016, respectively	$ (99)	$ (99)	$ (131)
Net unrealized loss on hedging derivatives, net of income taxes of $11 million at March 31, 2017 and July 1, 2016	(18)	(18)	(18)
Unrecognized postretirement obligations, net of income taxes of $213 million at March 31, 2017 and July 1, 2016	(344)	(344)	(346)
Accumulated other comprehensive loss	(461)	(461)	(495)
Tax effect on foreign currency translation		18	29
Tax effect on unrealized loss on hedging derivatives		11	11
Tax effect on unrecognized post-retirement obligations		213	$ 213
Accumulated Foreign Currency Adjustment Attributable to Parent | Critical Networks | Discontinued Operations, Disposed of by Sale | CapRock
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated foreign currency translation loss reclassified to earnings, net of tax	$ 51	$ 12