Earnings Per Share (EPS) (Reconciliation Of Income Used In Calculating Earnings Per Share) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended																12 Months Ended
	Jan. 31, 2012		Oct. 31, 2011		Jul. 31, 2011		Apr. 30, 2011		Jan. 31, 2011		Oct. 31, 2010		Jul. 31, 2010		Apr. 30, 2010		Jan. 31, 2012	Jan. 31, 2011	Jan. 31, 2010
Earnings Per Share (EPS) [Abstract]
Income (loss) from continuing operations, as reported	$ (160)	[1],[2]	$ (90)	[1],[2]	$ 112	[1],[2]	$ 130	[1],[2]	$ 126	[1]	$ 151	[1]	$ 157	[1]	$ 124	[1]	$ (8)	$ 558	$ 479
Less: allocation of undistributed earnings to participating securities																		(18)	(14)
Income (loss) from continuing operations, for computing basic EPS																	(8)	540	465
Net income, as reported	(161)	[1],[2]	(89)	[1],[2]	178	[1],[2]	131	[1],[2]	131	[1]	173	[1]	190	[1]	125	[1]	59	619	496
Less: allocation of undistributed earnings to participating securities, basic																		(20)	(15)
Net income, for computing basic EPS																	59	599	481
Less: allocation of undistributed earnings to participating securities, diluted																		(18)	(14)
Income (loss) from continuing operations, for computing diluted EPS																	(8)	540	465
Less: allocation of undistributed earnings to participating securities																		(20)	(15)
Net income, for computing diluted EPS																	$ 59	$ 599	$ 481

[1] Income from continuing operations and net income relate to SAIC only, see Science Applications' amounts detailed below.

[2] Includes loss provisions of $232 million and $308 million recorded in the third quarter and fourth quarter, respectively, in connection with resolution of the CityTime matter described in Note 17.