Gain (Loss) On Property Dispositions, Asset Impairment and Exit Costs

No definition available.

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- Definition

Number Of Sale Leaseback Transactions

+ References

No definition available.

+ Details

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Namespace Prefix:	aci_
Data Type:	xbrli:integerItemType
Balance Type:	na
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- References

No definition available.

+ Details

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- Definition

The amount of the gain recorded in connection with the transaction involving the sale of property to another party and the lease of the property back to the seller to be recognized in future periods.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 40
-Section 25
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=77913853&loc=d3e49567-112750

+ Details

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Data Type:	xbrli:monetaryItemType
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- Definition

Amount of reasonable estimate for income tax expense (benefit) for which accounting for tax effect for remeasurement of deferred tax from change in tax rate is incomplete pursuant to Tax Cuts and Jobs Act.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section S99
-Paragraph 2A
-Subparagraph (SAB Topic 5.EE.Q2(b))
-URI http://asc.fasb.org/extlink&oid=116825942&loc=SL116722634-122817

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QUARTERLY INFORMATION (unaudited) - Narrative (Details) $ in Millions	3 Months Ended				12 Months Ended
	Nov. 30, 2019 USD ($)	Sep. 07, 2019 USD ($) Leaseback	Sep. 07, 2019 USD ($) Transaction	Sep. 07, 2019 USD ($)	Feb. 29, 2020 USD ($)	Feb. 23, 2019 USD ($) Transaction	Feb. 24, 2018 USD ($)
Quarterly Financial Information Disclosure [Abstract]
Gross deferred gain on sale leaseback		$ 463.6	$ 463.6	$ 463.6
Number of sale leaseback transactions		3	3			3
Provisional tax benefit as a result of the Tax Act	$ 60.3
Net (gain) loss on property dispositions, asset impairment and lease exit costs				$ 135.8	$ 484.8	$ 165.0	$ (66.7)