Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries (Details 1) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 24, 2010	Sep. 24, 2010	Sep. 30, 2011
Condensed Combining Statements of Operations:
Net sales	$ 3,787	$ 3,835	$ 11,425	$ 11,154
Cost of sales	3,381	3,398	10,136	9,954
Operating (loss) income	406	437	1,289	1,200
Interest and other income (expense), net	3	3	15	10
Interest expense	57	64	200	176
Debt retirement charge		5	18	18
(Loss) income before income taxes	352	371	1,086	1,016
(Benefit) provision for income taxes	114	130	392	325
Net income	238	241	694	691
Net income attributable to noncontrolling interests	3	3	7	9
Net income attributable to L-3	235	238	687	682
L-3 Holdings (Parent) [Member]
Condensed Combining Statements of Operations:
Net sales	0			0
Cost of sales	17	20	62	51
Operating (loss) income	(17)	(20)	(62)	(51)
Interest and other income (expense), net	0			0
Interest expense	5	12	34	18
Debt retirement charge				0
(Loss) income before income taxes	(22)	(32)	(96)	(69)
(Benefit) provision for income taxes	(7)	(11)	(35)	(22)
Equity in net income of consolidated subsidiaries	250	259	748	729
Net income	235	238	687	682
Net income attributable to noncontrolling interests	0			0
Net income attributable to L-3	235	238	687	682
L-3 Communications [Member]
Condensed Combining Statements of Operations:
Net sales	916	806	2,445	2,713
Cost of sales	841	700	2,089	2,422
Operating (loss) income	75	106	356	291
Interest and other income (expense), net	31	31	95	94
Interest expense	57	64	200	175
Debt retirement charge		5	18	18
(Loss) income before income taxes	49	68	233	192
(Benefit) provision for income taxes	16	24	84	61
Equity in net income of consolidated subsidiaries	202	194	538	551
Net income	235	238	687	682
Net income attributable to noncontrolling interests	0			0
Net income attributable to L-3	235	238	687	682
Guarantor Subsidiaries [Member]
Condensed Combining Statements of Operations:
Net sales	2,331	2,530	7,542	6,838
Cost of sales	2,092	2,283	6,830	6,185
Operating (loss) income	239	247	712	653
Interest and other income (expense), net	(1)	(1)	4	(2)
Interest expense	27	27	82	82
Debt retirement charge				0
(Loss) income before income taxes	211	219	634	569
(Benefit) provision for income taxes	68	77	229	182
Equity in net income of consolidated subsidiaries	0			0
Net income	143	142	405	387
Net income attributable to noncontrolling interests	0			0
Net income attributable to L-3	143	142	405	387
Non-Guarantor Subsidiaries [Member]
Condensed Combining Statements of Operations:
Net sales	628	567	1,646	1,867
Cost of sales	536	483	1,425	1,611
Operating (loss) income	92	84	221	256
Interest and other income (expense), net	1	1	2	3
Interest expense	1	1	4	4
Debt retirement charge				0
(Loss) income before income taxes	92	84	219	255
(Benefit) provision for income taxes	30	29	79	82
Equity in net income of consolidated subsidiaries	0			0
Net income	62	55	140	173
Net income attributable to noncontrolling interests	0			0
Net income attributable to L-3	62	55	140	173
Eliminations [Member]
Condensed Combining Statements of Operations:
Net sales	(88)	(68)	(208)	(264)
Cost of sales	(105)	(88)	(270)	(315)
Operating (loss) income	17	20	62	51
Interest and other income (expense), net	(28)	(28)	(86)	(85)
Interest expense	(33)	(40)	(120)	(103)
Debt retirement charge				0
(Loss) income before income taxes	22	32	96	69
(Benefit) provision for income taxes	7	11	35	22
Equity in net income of consolidated subsidiaries	(452)	(453)	(1,286)	(1,280)
Net income	(437)	(432)	(1,225)	(1,233)
Net income attributable to noncontrolling interests	3	3	7	9
Net income attributable to L-3	$ (440)	$ (435)	$ (1,232)	$ (1,242)