Changes in Estimates (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Mar. 30, 2018	Mar. 31, 2017	Mar. 30, 2018	Mar. 31, 2017
Change in Accounting Estimate [Line Items]
Operating income	$ 256	$ 275	$ 800	$ 798
Contracts Accounted for under Percentage of Completion
Change in Accounting Estimate [Line Items]
Operating income	5	11	6	30
Operating income, net of tax	$ 4	$ 6	$ 4	$ 19
Operating income, per diluted share (in dollars per share)	$ 0.03	$ 0.05	$ 0.04	$ 0.14