Discontinued Operations - Income Statement (Details) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
	Jan. 01, 2017	Mar. 31, 2017	Apr. 01, 2016	Jan. 01, 2016	Mar. 31, 2017	Apr. 01, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue from product sales and services		$ 276	$ 369		$ 963	$ 1,144
Cost of product sales and services		(236)	(314)		(806)	(959)
Engineering, selling and administrative expenses		(23)	(36)		(95)	(118)
Impairment of goodwill and other assets		(238)	0		(240)	(367)
Non-operating income (loss)		(4)	(2)		3	(2)
Income (loss) before income taxes		(225)	17		(175)	(302)
Gain (loss) on sale of discontinued operations		5	0		(2)	(21)
Income tax (expense) benefit		141	(8)		127	18
Discontinued operations, net of income taxes		(79)	9		(50)	(305)
Broadcast Communications | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Non-operating income (loss)					(1)	(2)
Gain (loss) on sale of discontinued operations				$ (21)
Income tax (expense) benefit						4
Adjustemnt to gain (loss) on discontinued operations		3			3	(21)
IT Services Business | Critical Networks | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue from product sales and services		276	284		819	863
Cost of product sales and services		(236)	(244)		(698)	(735)
Engineering, selling and administrative expenses		(23)	(22)		(72)	(62)
Impairment of goodwill and other assets		(238)	0		(240)	0
Non-operating income (loss)		(4)	0		(4)	0
Income (loss) before income taxes		(225)	18		(195)	66
Gain (loss) on sale of discontinued operations		(21)	0		(28)	0
Income tax (expense) benefit		94	(7)		84	(24)
Discontinued operations, net of income taxes		(152)	11		(139)	42
CapRock | Critical Networks | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue from product sales and services		0	85		144	281
Cost of product sales and services		0	(70)		(108)	(224)
Engineering, selling and administrative expenses		0	(14)		(23)	(56)
Impairment of goodwill and other assets		0	0		0	(367)
Non-operating income (loss)		0	0		8	0
Income (loss) before income taxes		0	1		21	(366)
Gain (loss) on sale of discontinued operations	$ 23	23	0		23	0
Income tax (expense) benefit		47	(1)		43	38
Discontinued operations, net of income taxes		$ 70	$ 0		$ 87	$ (328)