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Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details) shares in Millions, $ in Millions	3 Months Ended	4 Months Ended
	Feb. 24, 2018 USD ($)	Jun. 16, 2018 USD ($) division store_format segment shares	Jun. 17, 2017 USD ($)	Feb. 25, 2018 USD ($)	Feb. 25, 2017 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Restricted cash	$ 10.5	$ 10.6	$ 29.0
LIFO expense (benefit)		9.5	15.7
Equity-based compensation expense		13.4	8.8
Income tax benefit from compensation expense		3.6	1.8
Compensation cost not yet recognized		$ 48.6
Number of unvested Phantom units \| shares		1.5
Period for recognition of unrecognized compensation cost		1 year 49 days
Income tax (benefit) expense		$ (3.0)	$ 0.4
Effective income tax rate on loss before income taxes		14.50%	(0.20%)
Provisional tax benefit as a result of the Tax Act	430.4
Number of divisions \| division		13
Number of reportable segments \| segment		1
Number of store format \| store_format		1
Contract liability related to gift cards	55.6	$ 45.6
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables, net	615.3	551.3
Other expense (income)		(40.8)	$ 16.4
Selling and administrative expenses		4,977.6	4,976.1
Decrease in net cash used in investing activities		277.6	455.4
Increase in cash, cash equivalents, and restricted cash from adoption of new accounting principle	680.8	1,247.6	1,092.4		$ 1,229.1
ASU 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other expense (income)		8.2
Selling and administrative expenses		(8.2)
ASU 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease in net cash used in investing activities			19.1
Increase in cash, cash equivalents, and restricted cash from adoption of new accounting principle			$ 19.1
Retained earnings \| ASU 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of adopting new accounting principle				$ 5.8
Pharmacy
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Receivables, net	$ 205.5	$ 193.2