Segment Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			6 Months Ended			12 Months Ended
	Sep. 28, 2012	Sep. 30, 2011		Sep. 28, 2012	Sep. 30, 2011		Mar. 30, 2012
Segment Reporting Information [Line Items]
Revenues	$ 3,854	$ 3,966		$ 7,811	$ 7,999
Operating income	298	(75)		481	105
Depreciation and amortization	273	290		536	568
NPS [Member] | Segment As Reported [Member]
Segment Reporting Information [Line Items]
Revenues	1,375	1,436	[1]	2,743	2,920	[1]
Operating income	150	(132)	[1]	251	(14)	[1]
Depreciation and amortization	40	40	[1]	81	76	[1]
NPS [Member] | Segment Out of Period Adjustments Increase (Decrease) [Member]
Segment Reporting Information [Line Items]
Revenues	1	2		0	0		(5)
Operating income	3	1		6	3		(10)
Depreciation and amortization	0	0		0	0
NPS [Member] | Segment Adjusted [Member]
Segment Reporting Information [Line Items]
Revenues	1,376	1,438		2,743	2,920
Operating income	153	(131)		257	(11)
Depreciation and amortization	40	40		81	76
MSS [Member] | Segment As Reported [Member]
Segment Reporting Information [Line Items]
Revenues	1,583	1,619		3,218	3,238
Operating income	88	45		183	54
Depreciation and amortization	189	206		373	407
MSS [Member] | Segment Out of Period Adjustments Increase (Decrease) [Member]
Segment Reporting Information [Line Items]
Revenues	2	2		3	4		(5)
Operating income	0	9		2	17		(33)
Depreciation and amortization	0	0		0	(1)
MSS [Member] | Segment Adjusted [Member]
Segment Reporting Information [Line Items]
Revenues	1,585	1,621		3,221	3,242
Operating income	88	54		185	71
Depreciation and amortization	189	206		373	406
BSS [Member] | Segment As Reported [Member]
Segment Reporting Information [Line Items]
Revenues	921	945		1,906	1,906
Operating income	64	34		80	91
Depreciation and amortization	39	38		75	71
BSS [Member] | Segment Out of Period Adjustments Increase (Decrease) [Member]
Segment Reporting Information [Line Items]
Revenues	0	4		9	(4)		(6)
Operating income	(12)	1		(13)	(2)		(22)
Depreciation and amortization	0	0		1	0
BSS [Member] | Segment Adjusted [Member]
Segment Reporting Information [Line Items]
Revenues	921	949		1,915	1,902
Operating income	52	35		67	89
Depreciation and amortization	39	38		76	71
Corporate [Member]
Segment Reporting Information [Line Items]
Revenues	3	3		6	6
Operating income	(4)	(22)		(33)	(26)
Depreciation and amortization	5	6		7	14
Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(28)	(37)		(62)	(71)
Operating income	0	0		0	0
Depreciation and amortization	0	0		0	0
Contracts Accounted for under Percentage of Completion, U.S. Claims [Member] | NPS [Member]
Segment Reporting Information [Line Items]
Change in accounting estimate, reduction in revenue		42			42
Change in accounting estimate, reduction in operating income		$ 269			$ 269

[1] The quarter and six months ended September 30, 2011 amounts include $42 million reduction of revenue and $269 million in reduction in operating income as a result of the settlement of claims with the U.S. government (see Note 17).