Condensed Combining Financial Information of L-3 Communications and Its Subsidiaries - Condensed Combining Balance Sheets (Detail) - USD ($) $ in Millions	Mar. 25, 2016	Dec. 31, 2015	Mar. 27, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 534	$ 207	$ 317	$ 442
Billed receivables, net	779	746
Contracts in process	2,226	2,081
Other current assets	$ 524	534
Assets of discontinued operations		664
Total current assets	$ 4,063	4,232
Goodwill	6,306	6,281
Other assets	$ 1,542	$ 1,554
Investment in and amounts due from consolidated subsidiaries
Total assets	$ 11,911	$ 12,067
Current portion of long-term debt	499	499
Current liabilities	$ 2,180	2,160
Liabilities of discontinued operations		220
Amounts due to consolidated subsidiaries
Other long-term liabilities	$ 1,654	1,634
Long-term debt	3,127	3,125
Total liabilities	7,460	7,638
L-3 shareholders' equity	4,378	4,355
Noncontrolling interests	73	74
Total equity	4,451	4,429	$ 5,302	$ 5,360
Total liabilities and equity	$ 11,911	$ 12,067
L-3 Communications Holdings, Inc. [Member]
Current assets:
Cash and cash equivalents
Billed receivables, net
Contracts in process
Other current assets
Assets of discontinued operations
Total current assets
Goodwill
Other assets
Investment in and amounts due from consolidated subsidiaries	$ 4,378	$ 4,355
Total assets	4,378	4,355
Current portion of long-term debt	$ 499	$ 499
Current liabilities
Liabilities of discontinued operations
Amounts due to consolidated subsidiaries
Other long-term liabilities
Long-term debt	$ 3,127	$ 3,125
Total liabilities
L-3 shareholders' equity	$ 4,378	$ 4,355
Noncontrolling interests
Total equity	$ 4,378	$ 4,355
Total liabilities and equity	4,378	4,355
L-3 Communications Corporation [Member]
Current assets:
Cash and cash equivalents	349	137	$ 210	$ 361
Billed receivables, net	276	278
Contracts in process	925	872
Other current assets	279	$ 288
Assets of discontinued operations
Total current assets	1,829	$ 1,575
Goodwill	2,339	2,318
Other assets	784	798
Investment in and amounts due from consolidated subsidiaries	5,393	5,609
Total assets	10,345	10,300
Current portion of long-term debt	499	499
Current liabilities	$ 913	$ 911
Liabilities of discontinued operations
Amounts due to consolidated subsidiaries
Other long-term liabilities	$ 1,428	$ 1,410
Long-term debt	3,127	3,125
Total liabilities	5,967	5,945
L-3 shareholders' equity	$ 4,378	$ 4,355
Noncontrolling interests
Total equity	$ 4,378	$ 4,355
Total liabilities and equity	10,345	$ 10,300
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	3		2	1
Billed receivables, net	256	$ 297
Contracts in process	1,030	958
Other current assets	134	137
Assets of discontinued operations		664
Total current assets	1,423	2,056
Goodwill	2,974	2,973
Other assets	500	496
Investment in and amounts due from consolidated subsidiaries	4,312	3,739
Total assets	$ 9,209	$ 9,264
Current portion of long-term debt
Current liabilities	$ 818	$ 899
Liabilities of discontinued operations		220
Amounts due to consolidated subsidiaries
Other long-term liabilities	$ 195	$ 195
Long-term debt
Total liabilities	$ 1,013	$ 1,314
L-3 shareholders' equity	$ 8,196	$ 7,950
Noncontrolling interests
Total equity	$ 8,196	$ 7,950
Total liabilities and equity	9,209	9,264
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents	189	165	116	142
Billed receivables, net	247	171
Contracts in process	271	251
Other current assets	111	$ 109
Assets of discontinued operations
Total current assets	818	$ 696
Goodwill	993	990
Other assets	$ 258	260
Investment in and amounts due from consolidated subsidiaries		111
Total assets	$ 2,069	$ 2,057
Current portion of long-term debt
Current liabilities	$ 456	$ 445
Liabilities of discontinued operations
Amounts due to consolidated subsidiaries	247
Other long-term liabilities	$ 31	$ 29
Long-term debt
Total liabilities	$ 734	$ 474
L-3 shareholders' equity	$ 1,335	$ 1,583
Noncontrolling interests
Total equity	$ 1,335	$ 1,583
Total liabilities and equity	2,069	2,057
Eliminations [Member]
Current assets:
Cash and cash equivalents	$ (7)	$ (95)	$ (11)	$ (62)
Billed receivables, net
Contracts in process
Other current assets
Assets of discontinued operations
Total current assets	$ (7)	$ (95)
Goodwill
Other assets
Investment in and amounts due from consolidated subsidiaries	$ (14,083)	$ (13,814)
Total assets	$ (14,090)	$ (13,909)
Current portion of long-term debt
Current liabilities	$ (7)	$ (95)
Liabilities of discontinued operations
Amounts due to consolidated subsidiaries	$ (247)
Other long-term liabilities
Long-term debt
Total liabilities	$ (254)	$ (95)
L-3 shareholders' equity	(13,909)	(13,888)
Noncontrolling interests	73	74
Total equity	(13,836)	(13,814)
Total liabilities and equity	$ (14,090)	$ (13,909)