Debt Instrument, Capitalized Fee Amount

No definition available.

Name:	awi_DebtInstrumentCapitalizedFeeAmount
Namespace Prefix:	awi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Debt Instrument, Floor Interest Rate

+ References

No definition available.

+ Details

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Namespace Prefix:	awi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Dividend received from AFI upon separation from AWI on April 1, 2016.

+ References

No definition available.

+ Details

Name:	awi_DividendsReceived
Namespace Prefix:	awi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Letter of credit maximum sublimit amount.

+ References

No definition available.

+ Details

Name:	awi_LetterOfCreditMaximumSublimitAmount
Namespace Prefix:	awi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of the fee that accompanies borrowing money under the debt instrument.

+ References

+ Details

Name:	us-gaap_DebtInstrumentFeeAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.8)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_DebtInstrumentAxis=awi_TermLoanA1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=awi_TermLoanB1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=awi_AmendedSecuritizationFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=awi_SecuritizationFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ExtinguishmentOfDebtAxis=us-gaap_LongTermDebtMember
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Debt (Narrative) (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
Debt (Narrative) (Details) - USD ($)	Mar. 31, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2016	Apr. 01, 2016
Debt Instrument [Line Items]
Bank, legal and other fees		$ 9,300,000
Unamortized debt financing costs written off		1,100,000
AFI [Member]
Debt Instrument [Line Items]
Cash dividend from AFI planned to reduce total debt outstanding					$ 50,000,000
Term Loan A [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity				$ 600,000,000
Interest rate spread			2.50%	2.00%
Maturity date			Mar. 01, 2018
Term Loan A [Member] \| Extended Maturity [Member]
Debt Instrument [Line Items]
Maturity date				Apr. 01, 2021
Term Loan B [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity				$ 250,000,000
Interest rate spread			2.50%	3.25%
Floor interest rate			1.00%	0.75%
Maturity date			Nov. 01, 2020
Term Loan B [Member] \| Extended Maturity [Member]
Debt Instrument [Line Items]
Maturity date				Apr. 01, 2023
Senior Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	$ 1,275,000,000		$ 1,275,000,000
New credit facility amount				$ 1,050,000,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity				200,000,000
Credit facility, maximum borrowing capacity sublimit				$ 150,000,000
Interest rate spread			2.50%	2.00%
Maturity date			Mar. 01, 2018
Revolving Credit Facility [Member] \| Extended Maturity [Member]
Debt Instrument [Line Items]
Maturity date				Apr. 01, 2021
Amended Securitization Facility [Member]
Debt Instrument [Line Items]
Credit facility, maximum borrowing capacity	100,000,000		$ 100,000,000
New credit facility amount	$ 40,000,000		$ 40,000,000
Amended Securitization Facility [Member] \| Extended Maturity [Member]
Debt Instrument [Line Items]
Maturity date	Mar. 01, 2019
Securitization Facility [Member]
Debt Instrument [Line Items]
Amount outstanding				$ 0
Long-term Debt [Member]
Debt Instrument [Line Items]
Fees capitalized and amortized into interest expense		$ 8,100,000