Condensed Consolidating Statement of Cash Flows (Details 3) - USD ($) $ in Millions	3 Months Ended
	Oct. 02, 2015	Sep. 26, 2014
Guarantor Obligations [Line Items]
Net Cash Provided by (Used in) Operating Activities	$ 64	$ 80
Investing Activities
Additions of property, plant and equipment	(26)	(41)
Proceeds from sale of property, plant and equipment	2
Proceeds from sale of Cyber Integration Center	0	7
Net Cash Provided by (Used in) Investing Activities	(24)	(34)
Financing Activities
Proceeds from borrowings, net of issuance costs	41	3
Repayments of borrowings	(173)	(9)
Proceeds from exercises of employee stock options	19	18
Repurchases of common stock	0	(100)
Cash dividends	(64)	(50)
Other financing activities	(15)	(12)
Net cash provided by (used in) financing activities	(192)	(150)
Effect of exchange rate changes on cash and cash equivalents	(9)	(8)
Net increase in cash and cash equivalents	(161)	(112)
Cash and cash equivalents, beginning of year	481	561
Cash and cash equivalents, end of quarter	320	449
Consolidation, Eliminations [Member]
Financing Activities
Cash and cash equivalents, beginning of year	0
Cash and cash equivalents, end of quarter	0
Consolidation, Eliminations [Member] | Statement of Cash Flows [Member]
Guarantor Obligations [Line Items]
Net Cash Provided by (Used in) Operating Activities	0	0
Investing Activities
Intercompany loans (investing activities)	56	(58)
Net cash paid for acquired businesses	0	0
Cash paid for intangible assets	0	0
Cash paid for cost-method investment	0	0
Additions of property, plant and equipment	0	0
Additions of capitalized software	0	0
Proceeds from sale of property, plant and equipment	0	0
Proceeds from sale of business	0	0
Proceeds from sale of Cyber Integration Center	0	0
Proceeds from sale of securities available-for-sale	0	0
Net Cash Provided by (Used in) Investing Activities	56	(58)
Financing Activities
Intercompany loans (financing activities)	(56)	58
Proceeds from borrowings, net of issuance costs	0	0
Repayments of borrowings	0	0
Payment of contingent consideration	0	0
Proceeds from exercises of employee stock options	0	0
Repurchases of common stock	0	0
Cash dividends	0	0
Other financing activities	0	0
Net cash provided by (used in) financing activities	(56)	58
Effect of exchange rate changes on cash and cash equivalents	0	0
Net increase in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of year	0	0
Cash and cash equivalents, end of quarter	0	0
Harris Parent Company [Member] | Financial Guarantee [Member]
Financing Activities
Effect of exchange rate changes on cash and cash equivalents		0
Cash and cash equivalents, beginning of year	151
Cash and cash equivalents, end of quarter	64
Harris Parent Company [Member] | Financial Guarantee [Member] | Statement of Cash Flows [Member]
Guarantor Obligations [Line Items]
Net Cash Provided by (Used in) Operating Activities	177	212
Investing Activities
Intercompany loans (investing activities)	(61)	(35)
Net cash paid for acquired businesses	0	0
Cash paid for intangible assets	0	0
Cash paid for cost-method investment	0	0
Additions of property, plant and equipment	(15)	(31)
Additions of capitalized software	0	0
Proceeds from sale of property, plant and equipment	2	0
Proceeds from sale of business	0	0
Proceeds from sale of Cyber Integration Center	0	7
Proceeds from sale of securities available-for-sale	0	0
Net Cash Provided by (Used in) Investing Activities	(74)	(59)
Financing Activities
Intercompany loans (financing activities)	(5)	(93)
Proceeds from borrowings, net of issuance costs	25	0
Repayments of borrowings	(150)	0
Payment of contingent consideration	0	0
Proceeds from exercises of employee stock options	19	18
Repurchases of common stock	0	(100)
Cash dividends	(64)	(50)
Other financing activities	(15)	(12)
Net cash provided by (used in) financing activities	(190)	(237)
Effect of exchange rate changes on cash and cash equivalents	0
Net increase in cash and cash equivalents	(87)	(84)
Cash and cash equivalents, beginning of year	151	252
Cash and cash equivalents, end of quarter	64	168
Exelis Parent Company [Member] | Financial Guarantee [Member]
Financing Activities
Cash and cash equivalents, beginning of year	54
Cash and cash equivalents, end of quarter	49
Exelis Parent Company [Member] | Financial Guarantee [Member] | Statement of Cash Flows [Member]
Guarantor Obligations [Line Items]
Net Cash Provided by (Used in) Operating Activities	1
Investing Activities
Intercompany loans (investing activities)	0
Net cash paid for acquired businesses	0
Cash paid for intangible assets	0
Cash paid for cost-method investment	0
Additions of property, plant and equipment	(6)
Additions of capitalized software	0
Proceeds from sale of property, plant and equipment	0
Proceeds from sale of business	0
Proceeds from sale of Cyber Integration Center	0
Proceeds from sale of securities available-for-sale	0
Net Cash Provided by (Used in) Investing Activities	(6)
Financing Activities
Intercompany loans (financing activities)	0
Proceeds from borrowings, net of issuance costs	0
Repayments of borrowings	0
Payment of contingent consideration	0
Proceeds from exercises of employee stock options	0
Repurchases of common stock	0
Cash dividends	0
Other financing activities	0
Net cash provided by (used in) financing activities	0
Effect of exchange rate changes on cash and cash equivalents	0
Net increase in cash and cash equivalents	(5)
Cash and cash equivalents, beginning of year	54
Cash and cash equivalents, end of quarter	49
Non-Guarantor Subsidiaries [Member]
Financing Activities
Cash and cash equivalents, beginning of year	276
Cash and cash equivalents, end of quarter	207
Non-Guarantor Subsidiaries [Member] | Statement of Cash Flows [Member]
Guarantor Obligations [Line Items]
Net Cash Provided by (Used in) Operating Activities	(114)	(132)
Investing Activities
Intercompany loans (investing activities)	5	93
Net cash paid for acquired businesses	0	0
Cash paid for intangible assets	0	0
Cash paid for cost-method investment	0	0
Additions of property, plant and equipment	(5)	(10)
Additions of capitalized software	0	0
Proceeds from sale of property, plant and equipment	0	0
Proceeds from sale of business	0	0
Proceeds from sale of Cyber Integration Center	0	0
Proceeds from sale of securities available-for-sale	0	0
Net Cash Provided by (Used in) Investing Activities	0	83
Financing Activities
Intercompany loans (financing activities)	61	35
Proceeds from borrowings, net of issuance costs	16	3
Repayments of borrowings	(23)	(9)
Payment of contingent consideration	0	0
Proceeds from exercises of employee stock options	0	0
Repurchases of common stock	0	0
Cash dividends	0	0
Other financing activities	0	0
Net cash provided by (used in) financing activities	54	29
Effect of exchange rate changes on cash and cash equivalents	(9)	(8)
Net increase in cash and cash equivalents	(69)	(28)
Cash and cash equivalents, beginning of year	276	309
Cash and cash equivalents, end of quarter	$ 207	$ 281