Settlement of Claims with U.S. Government (Details) (USD $)	3 Months Ended			9 Months Ended
	Dec. 28, 2012	Dec. 30, 2011	Sep. 30, 2011	Dec. 28, 2012	Dec. 30, 2011	Jul. 01, 2011 Claims	Dec. 24, 2009	Sep. 29, 2006 Claims
Settlement of Claims with U.S. Government [Line Items]
Proceeds from Legal Settlements			$ 277,000,000
Contract Extension Received, Period				5 years
Contract Extension Base, Period				4 years
Contract Extension Received Option, Period				1 year
Estimated value of contract extension			1,000,000,000
Pre-tax charge to write down claim related assets			269,000,000
Claim related unbilled receivables			379,000,000
Claim related deferred costs			227,000,000
Estimated fair value of the contract extension			45,000,000
Previously unapplied payments			15,000,000
Change in accounting estimate, reduction in operating income		1,485,000,000
Pre-tax charge to write down claim related assets recorded as a separately itemized charge to cost of services	0	0	227,000,000	0	227,000,000
Contract Extension Amortization, Period				4 years
Original Contract Award, Period				10 years
Extension To Original Contract, Period				2 years
Number Of Claims Outstanding								14
Original Amount Of Claims								858,000,000
Amended Claim Amount Of Reduction Gross							35,000,000
Number of claims asserted						14
Approximate value of claims asserted						675,000,000
Contracts Accounted for under Percentage of Completion, U.S. Claims [Member] | NPS [Member]
Settlement of Claims with U.S. Government [Line Items]
Change in accounting estimate, reduction in operating income			269,000,000
Change in accounting estimate, reduction in revenue			$ 42,000,000