Changes in Estimates (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Dec. 29, 2017	Dec. 30, 2016	Dec. 29, 2017	Dec. 30, 2016
Change in Accounting Estimate [Line Items]
Operating income	$ 272	$ 277	$ 544	$ 523
Contracts Accounted for under Percentage of Completion
Change in Accounting Estimate [Line Items]
Operating income	(10)	6	$ 1	19
Operating income, net of tax	$ (7)	$ 4		$ 12
Operating income per diluted share (in dollars per share)	$ (0.06)	$ 0.03		$ 0.10