Segment and Geographic Information Geographic revenue and property and equipment, net (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 28, 2014	Mar. 29, 2013	Mar. 30, 2012
Segment Reporting Information [Line Items]
Revenue	$ 12,998	$ 14,195	$ 14,476
Property and Equipment, Net	2,031	2,184	2,441
Total Assets	11,389	11,251	11,189
Capital Expenditures	595	568	829
Percentage of revenues derived from the US federal government (in hundredths)	30.00%	31.00%	32.00%
Percentage of accounts receivable due from the US federal government (in hundredths)	25.00%	30.00%
Maximum percentage of revenues from transactions with a single commercial customer (in hundredths)	10.00%	10.00%	10.00%
United States [Member]
Segment Reporting Information [Line Items]
Revenue	7,766	8,571	8,603
Property and Equipment, Net	1,177	1,273	1,406
Total Assets	6,728	6,454	6,198
Capital Expenditures	333	290	444
United Kingdom [Member]
Segment Reporting Information [Line Items]
Revenue	1,699	1,729	1,576
Property and Equipment, Net	335	320	367
Total Assets	1,614	1,389	1,329
Capital Expenditures	89	70	77
Other Europe [Member]
Segment Reporting Information [Line Items]
Revenue	2,150	2,193	2,430
Property and Equipment, Net	253	217	237
Total Assets	1,473	1,487	1,115
Capital Expenditures	85	80	90
Other International [Member]
Segment Reporting Information [Line Items]
Revenue	1,383	1,702	1,867
Property and Equipment, Net	266	374	431
Total Assets	1,574	1,921	2,547
Capital Expenditures	$ 88	$ 128	$ 218