Net (Loss) Earnings Per Share - Calculation of Basic and Diluted Net Earnings (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Sep. 08, 2018	Sep. 09, 2017	Sep. 08, 2018	Sep. 09, 2017
Earnings Per Share [Abstract]
Net (loss) earnings from continuing operations	$ (55)	$ (1)	$ (82)	$ 8
Less net earnings attributable to noncontrolling interests	1	0	1	(1)
Net loss from continuing operations attributable to SUPERVALU INC.	(54)	(1)	(81)	7
(Loss) income from discontinued operations, net of tax	(3)	(24)	3	(21)
Net loss attributable to SUPERVALU INC.	$ (57)	$ (25)	$ (78)	$ (14)
Weighted average number of shares outstanding-basic	39	38	39	38
Dilutive impact of stock-based awards	0	0	0	0
Weighted average number of shares outstanding-diluted	39	38	39	38
Basic net loss per share attributable to SUPERVALU INC.:
Continuing operations (in dollars per share)	$ (1.41)	$ (0.02)	$ (2.11)	$ 0.20
Discontinued operations (in dollars per share)	(0.08)	(0.64)	0.07	(0.55)
Basic net earnings per share (in dollars per share)	(1.49)	(0.65)	(2.04)	(0.36)
Diluted net loss per share attributable to SUPERVALU INC.:
Continuing operations (in dollars per share)	(1.41)	(0.02)	(2.11)	0.20
Discontinued operations (in dollars per share)	(0.08)	(0.64)	0.07	(0.55)
Diluted net earnings per share (in dollars per share)	$ (1.49)	$ (0.65)	$ (2.04)	$ (0.36)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	1	2	1	2