Stock-Based Compensation - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended	8 Months Ended	12 Months Ended				12 Months Ended													12 Months Ended		12 Months Ended
	Jun. 12, 2013	Sep. 27, 2013	Jan. 31, 2014	Jan. 31, 2013	Jan. 31, 2012	Mar. 31, 2013	Jan. 31, 2014 Performance Based Restricted Stock Awards	Jan. 31, 2014 Stock Options	Jan. 31, 2014 Stock Options Maximum	Jan. 31, 2014 Outside Directors	Jan. 31, 2014 Performance-Based Stock Awards	Jan. 31, 2014 Vesting Stock Awards	Jan. 31, 2014 2006 Equity Incentive Plan	Jan. 31, 2014 2006 Equity Incentive Plan Stock Options	Jan. 31, 2013 2006 Equity Incentive Plan Stock Options	Jan. 31, 2014 2006 Equity Incentive Plan Outside Directors	Jan. 31, 2014 2006 Equity Incentive Plan Group One	Jan. 31, 2014 2006 Equity Incentive Plan Group Two	Jan. 31, 2014 Employee Stock Purchase Plan	Jan. 31, 2014 SAIC Separation Adjustment [Member]	Sep. 27, 2013 SAIC Separation Adjustment [Member]	Jan. 31, 2014 SAIC Separation Adjustment [Member] Performance-Based Stock Awards	Jun. 12, 2013 Opening [Member]	Jun. 11, 2013 Closing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Special dividend			$ 4			$ 4.00
Stock issued to Leidos shareholder upon divestiture of SAIC, ratio																					1.4523
Period of exercise of vested options after participants death or disability													18 months
Stock awards exercisable period (in months)													six
Percentage of stock awards vest or exercisable after one year													20.00%
Percentage of stock awards vest or exercisable after two years													20.00%
Percentage of stock awards vest or exercisable after three years													20.00%
Percentage of stock awards vest or exercisable after four years													40.00%
Stock reserved for future issuance													3.8
Vesting period								4 years		1 year	3 years			4 years		1 year	4 years	7 years
Award vesting period (in years)													7 years
Vesting interest each year													one-third
Years of interest rates													fifth, sixth and seventh
Percentage of stock compensation plans awards that vest after January 1, 2006													100.00%
Percentage of market price per share for stock purchase program																			15.00%
Percentage of market price for employee purchase program for stock purchases during non-compensatory period																			5.00%
Shares authorized and reserved for future issuance under the ESPP																			11.1
Expected term		5 years	4 years 9 months 18 days	5 years	4 years 10 months 24 days				10 years					5 years	7 years
Unrecognized compensation cost, net of estimated forfeitures							$ 0.5	$ 8.0				$ 68.0
Expected weighted-average period of recognition, years							1 year	1 year 7 months 6 days				1 year 10 months 24 days
Fair value of vesting awards that vested			49.0	66.0	67.0						1.5
Maximum percentage that will ultimately be awarded											150.00%
Increase of expense related to the modification																				3
Additional incremental fair value																				3
Stock based compensation from discontinued operations																				6
Weighted average modification fair value																				$ 1.02
Modification results																						$ 1
Incremental share factor	1.0713
Share price																							$ 55.52	$ 59.48
Decrease in share factor	0.9334