Legal proceedings and contingencies (Details) $ in Millions		3 Months Ended				9 Months Ended
	Mar. 31, 2016 party	Apr. 01, 2016 USD ($)	Jan. 01, 2016 USD ($)	Apr. 03, 2015 USD ($)	Dec. 28, 2012 USD ($)	Apr. 01, 2016 USD ($)	Apr. 03, 2015 USD ($)
Loss Contingencies [Line Items]
Adjustment to loss on sales of businesses, net						$ 20	$ 0
Gain on sale of discontinued operations after-tax		$ (2)		$ 0		(19)	$ 0
Broadcast Communications
Loss Contingencies [Line Items]
Asset sale agreement					$ 225
Asset sale agreement, cash					160
Asset sale agreement, promissory note					15
Asset sale agreement, earnout					$ 50
Adjustment to loss on sales of businesses, net			$ 21
Gain on sale of discontinued operations after-tax			$ (17)
Exelis | Passaic River Alaska
Loss Contingencies [Line Items]
Estimated cost for all participating parties of EPA's preferred alternative						$ 1,380
Number of Responsible Parties Notified | party	100