Financial Information of L-3 Communications and Its Subsidiaries (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating activities:
Net cash from operating activities	$ 1,484	$ 1,461	$ 1,407
Investing activities:
Business acquisitions, net of cash acquired	(20)	(756)	(90)
Other investing activities	(183)	(189)	(182)
Net cash used in investing activities	(203)	(945)	(272)
Financing activities:
Proceeds from sale of senior notes	1,143	797	996
Repayment of borrowings under term loan facility			(650)
Redemption of senior subordinated notes	(1,150)	(800)	(750)
Redemption of CODES	(11)
Redemption of senior subordinated notes and CODES	(1,161)
Common stock repurchased	(958)	(834)	(505)
Dividends paid on L-3 Holdings' common stock	(188)	(184)	(165)
Other financing activities	44	103	69
Net cash used in financing activities	(1,120)	(918)	(1,005)
Effect of foreign currency exchange rate changes on cash	(4)	(7)	19
Net (decrease) increase in cash	157	(409)	149
Cash and cash equivalents, beginning of the year	607	1,016	867
Cash and cash equivalents, end of the year	764	607	1,016
L-3 Holdings (Parent) [Member]
Operating activities:
Net cash from operating activities	1,157	1,018	670
Investing activities:
Investments in L-3 Communications	(55)	(116)	(87)
Net cash used in investing activities	(55)	(116)	(87)
Financing activities:
Redemption of CODES	(11)
Common stock repurchased	(958)	(834)	(505)
Dividends paid on L-3 Holdings' common stock	(188)	(184)	(165)
Other financing activities	55	116	87
Net cash used in financing activities	(1,102)	(902)	(583)
Cash and cash equivalents, beginning of the year	0	0	0
Cash and cash equivalents, end of the year	0	0	0
L-3 Communications [Member]
Operating activities:
Net cash from operating activities	501	288	132
Investing activities:
Business acquisitions, net of cash acquired	(20)	(756)	(90)
Other investing activities	(84)	(79)	(64)
Net cash used in investing activities	(104)	(835)	(154)
Financing activities:
Proceeds from sale of senior notes	1,143	797	996
Repayment of borrowings under term loan facility			(650)
Redemption of senior subordinated notes	(1,150)	(800)	(750)
Dividends paid to L-3 Holdings	(1,157)	(1,018)	(670)
Investments from L-3 Holdings	55	116	87
Other financing activities	1,099	912	1,086
Net cash used in financing activities	(10)	7	99
Net (decrease) increase in cash	387	(540)	77
Cash and cash equivalents, beginning of the year	257	797	720
Cash and cash equivalents, end of the year	644	257	797
Guarantor Subsidiaries [Member]
Operating activities:
Net cash from operating activities	988	953	1,093
Investing activities:
Other investing activities	(77)	(102)	(103)
Net cash used in investing activities	(77)	(102)	(103)
Financing activities:
Other financing activities	(912)	(852)	(988)
Net cash used in financing activities	(912)	(852)	(988)
Net (decrease) increase in cash	(1)	(1)	2
Cash and cash equivalents, beginning of the year	3	4	2
Cash and cash equivalents, end of the year	2	3	4
Non-Guarantor Subsidiaries [Member]
Operating activities:
Net cash from operating activities	252	243	248
Investing activities:
Other investing activities	(22)	(8)	(15)
Net cash used in investing activities	(22)	(8)	(15)
Financing activities:
Other financing activities	(479)	(110)	(116)
Net cash used in financing activities	(479)	(110)	(116)
Effect of foreign currency exchange rate changes on cash	(4)	(7)	19
Net (decrease) increase in cash	(253)	118	136
Cash and cash equivalents, beginning of the year	482	364	228
Cash and cash equivalents, end of the year	229	482	364
Eliminations [Member]
Operating activities:
Net cash from operating activities	(1,414)	(1,041)	(736)
Investing activities:
Investments in L-3 Communications	55	116	87
Net cash used in investing activities	55	116	87
Financing activities:
Dividends paid to L-3 Holdings	1,157	1,018	670
Investments from L-3 Holdings	(55)	(116)	(87)
Other financing activities	281	37
Net cash used in financing activities	1,383	939	583
Net (decrease) increase in cash	24	14	(66)
Cash and cash equivalents, beginning of the year	(135)	(149)	(83)
Cash and cash equivalents, end of the year	$ (111)	$ (135)	$ (149)