Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Condensed Combining Statements of Cash Flows (Detail) (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 27, 2013	Sep. 28, 2012
Operating activities:
Net cash from operating activities	$ 617
Net cash from operating activities from continuing operations	617	692
Investing activities:
Business acquisitions, net of cash acquired	(2)	(349)
Investments in L-3 Communications
Other investing activities	(139)	212
Net cash used in investing activities from continuing operations	(141)	(137)
Net cash used in investing activities	(141)
Financing activities:
Redemption of senior subordinated notes		(250)
Common stock repurchased	(404)	(504)
Dividends paid on L-3 Holdings common stock	(151)	(149)
Dividends paid to L-3 Holdings
Investments from L-3 Holdings
Other financing activities	109	20
Net cash used in financing activities from continuing operations	(446)	(883)
Net cash used in financing activities	(446)
Effect of foreign currency exchange rate changes on cash	(2)	4
Net increase in cash and cash equivalents of discontinued operations		74
Net increase (decrease) in cash and cash equivalents	28	(250)
Cash and cash equivalents, beginning of the period	349	764
Cash and cash equivalents, end of the period	377	514
L-3 Communications Holdings, Inc. [Member]
Operating activities:
Net cash from operating activities	555
Net cash from operating activities from continuing operations		653
Investing activities:
Business acquisitions, net of cash acquired
Investments in L-3 Communications	(104)	(27)
Other investing activities
Net cash used in investing activities from continuing operations		(27)
Net cash used in investing activities	(104)
Financing activities:
Common stock repurchased	(404)	(504)
Dividends paid on L-3 Holdings common stock	(151)	(149)
Dividends paid to L-3 Holdings
Investments from L-3 Holdings
Other financing activities	104	27
Net cash used in financing activities from continuing operations		(626)
Net cash used in financing activities	(451)
Effect of foreign currency exchange rate changes on cash
Net increase (decrease) in cash and cash equivalents
Cash and cash equivalents, beginning of the period
Cash and cash equivalents, end of the period
L-3 Communications Corporation's [Member]
Operating activities:
Net cash from operating activities	86
Net cash from operating activities from continuing operations		83
Investing activities:
Business acquisitions, net of cash acquired	(2)	(349)
Investments in L-3 Communications
Other investing activities	(70)	262
Net cash used in investing activities from continuing operations		(87)
Net cash used in investing activities	(72)
Financing activities:
Redemption of senior subordinated notes		(250)
Common stock repurchased
Dividends paid on L-3 Holdings common stock
Dividends paid to L-3 Holdings	(555)	(653)
Investments from L-3 Holdings	104	27
Other financing activities	345	523
Net cash used in financing activities from continuing operations		(353)
Net cash used in financing activities	(106)
Effect of foreign currency exchange rate changes on cash
Net increase in cash and cash equivalents of discontinued operations		74
Net increase (decrease) in cash and cash equivalents	(92)	(283)
Cash and cash equivalents, beginning of the period	246	644
Cash and cash equivalents, end of the period	154	361
Guarantor Subsidiaries [Member]
Operating activities:
Net cash from operating activities	523
Net cash from operating activities from continuing operations		527
Investing activities:
Business acquisitions, net of cash acquired
Investments in L-3 Communications
Other investing activities	(53)	(41)
Net cash used in investing activities from continuing operations		(41)
Net cash used in investing activities	(53)
Financing activities:
Common stock repurchased
Dividends paid on L-3 Holdings common stock
Dividends paid to L-3 Holdings
Investments from L-3 Holdings
Other financing activities	(469)	(485)
Net cash used in financing activities from continuing operations		(485)
Net cash used in financing activities	(469)
Effect of foreign currency exchange rate changes on cash
Net increase (decrease) in cash and cash equivalents	1	1
Cash and cash equivalents, beginning of the period
Cash and cash equivalents, end of the period	1	1
Non-Guarantor Subsidiaries [Member]
Operating activities:
Net cash from operating activities	101
Net cash from operating activities from continuing operations		182
Investing activities:
Business acquisitions, net of cash acquired
Investments in L-3 Communications
Other investing activities	(16)	(9)
Net cash used in investing activities from continuing operations		(9)
Net cash used in investing activities	(16)
Financing activities:
Common stock repurchased
Dividends paid on L-3 Holdings common stock
Dividends paid to L-3 Holdings
Investments from L-3 Holdings
Other financing activities	(81)	(182)
Net cash used in financing activities from continuing operations		(182)
Net cash used in financing activities	(81)
Effect of foreign currency exchange rate changes on cash	(2)	4
Net increase (decrease) in cash and cash equivalents	2	(5)
Cash and cash equivalents, beginning of the period	242	222
Cash and cash equivalents, end of the period	244	217
Eliminations [Member]
Operating activities:
Net cash from operating activities	(648)
Net cash from operating activities from continuing operations		(753)
Investing activities:
Business acquisitions, net of cash acquired
Investments in L-3 Communications	104	27
Other investing activities
Net cash used in investing activities from continuing operations		27
Net cash used in investing activities	104
Financing activities:
Common stock repurchased
Dividends paid on L-3 Holdings common stock
Dividends paid to L-3 Holdings	555	653
Investments from L-3 Holdings	(104)	(27)
Other financing activities	210	137
Net cash used in financing activities from continuing operations		763
Net cash used in financing activities	661
Effect of foreign currency exchange rate changes on cash
Net increase (decrease) in cash and cash equivalents	117	37
Cash and cash equivalents, beginning of the period	(139)	(102)
Cash and cash equivalents, end of the period	$ (22)	$ (65)