Schedule of Selected Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								11 Months Ended		12 Months Ended
	Jan. 01, 2016	Oct. 02, 2015	Jul. 03, 2015	Apr. 03, 2015	Jan. 30, 2015	Oct. 31, 2014	Aug. 01, 2014	May. 02, 2014	Jan. 01, 2016	Jan. 02, 2015	Jan. 30, 2015	Jan. 31, 2014
Quarterly Financial Information [Line Items]
Revenues	$ 1,281	$ 1,302	$ 1,257	$ 1,246	$ 1,169	$ 1,276	$ 1,306	$ 1,312	$ 4,712	$ 4,690	$ 5,063	$ 5,755
Operating income	102	94	64	38	37	72	(410)	87	320	(191)	(214)	163
Income (loss) from continuing operations	127	49	37	23	26	38	(439)	45	243	(323)	(330)	84
Income from discontinued operations	0	0	0	18	18	(4)	1	(8)	(1)	(11)	7	80
Net income (loss)	$ 127	$ 49	$ 37	$ 41	$ 44	$ 34	$ (438)	$ 37	$ 242	$ (334)	$ (323)	$ 164
Basic earnings (loss) per share ( usd per share)	$ 1.76	$ 0.68	$ 0.51	$ 0.32	$ 0.36	$ 0.52	$ (5.93)	$ 0.58	$ 3.32	$ (4.51)	$ (4.36)	$ 1.94
Diluted earnings (loss) per share ( usd per share)	$ 1.72	$ 0.67	$ 0.50	$ 0.31	$ 0.35	$ 0.51	$ (5.93)	$ 0.58	$ 3.27	$ (4.51)	$ (4.36)	$ 1.94
Leidos, Inc.
Quarterly Financial Information [Line Items]
Revenues									$ 4,712	$ 4,690	$ 5,063	$ 5,755
Operating income									320	(191)	(214)	163
Income (loss) from continuing operations	$ 128	$ 51	$ 39	$ 25	$ 27	$ 40	$ (437)	$ 46	249	(317)	(324)	86
Income from discontinued operations									(1)	(11)	7	80
Net income (loss)	$ 127	$ 51	$ 39	$ 43	$ 45	$ 36	$ (436)	$ 38	$ 248	$ (328)	$ (317)	$ 166