Leases (Schedule Of Future Minimum Payments) (Details) $ in Millions	Dec. 31, 2016 USD ($)
Leases [Abstract]
Total minimum lease payments, 2017	$ 7.4
Total minimum lease payments, 2018	6.0
Total minimum lease payments, 2019	4.6
Total minimum lease payments, 2020	3.2
Total minimum lease payments, 2021	2.4
Total minimum lease payments, Thereafter	2.4
Total minimum lease payments, Total	26.0
Sublease (Income), 2017	(0.1)
Sublease (Income), 2018	(0.1)
Sublease (Income), 2019	(0.1)
Sublease (Income), 2020	(0.1)
Sublease (Income), Total	(0.4)
Net minimum lease payments, 2017	7.3
Net minimum lease payments, 2018	5.9
Net minimum lease payments, 2019	4.5
Net minimum lease payments, 2020	3.1
Net minimum lease payments, 2021	2.4
Net minimum lease payments, Thereafter	2.4
Net minimum lease payments, Total	$ 25.6

Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Next Twelve Months

No definition available.

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

- Definition

Operating leases, future minimum payments due, future minimum sublease rentals, due in year four.

+ References

No definition available.

+ Details

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

- Definition

Operating leases, future minimum payments due, future minimum sublease rentals, due in year three.

+ References

No definition available.

+ Details

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

- Definition

Operating Leases, Future Minimum Payments Due, Future Minimum Sublease Rentals, Due in Year Two

+ References

No definition available.

+ Details

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

- Definition

Operating Leases, Future Minimum Payments Due Net, Next Twelve Months

+ References

No definition available.

+ Details

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

- Definition

Operating Leases, Future Minimum Payments Net, Due

+ References

No definition available.

+ Details

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

- Definition

Operating Leases, Future Minimum Payments Net, Due in Five Years

+ References

No definition available.

+ Details

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

- Definition

Operating Leases, Future Minimum Payments Net, Due in Four Years

+ References

No definition available.

+ Details

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

- Definition

Operating Leases, Future Minimum Payments Net, Due in Three Years

+ References

No definition available.

+ Details

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

- Definition

Operating Leases, Future Minimum Payments Net, Due in Two Years

+ References

No definition available.

+ Details

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

- Definition

Operating Leases, Future Minimum Payments Net, Due Thereafter

+ References

No definition available.

+ Details

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

- References

No definition available.

+ Details

Name:	us-gaap_LeasesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 55
-Paragraph 40
-Subparagraph (Note 3)
-URI http://asc.fasb.org/extlink&oid=6584154&loc=d3e38371-112697

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41502-112717

+ Details

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

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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

- Definition

Contractually required future rental payments receivable on noncancelable subleasing arrangements.

+ References

+ Details

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

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41502-112717

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 55
-Paragraph 40
-Subparagraph (Note 3)
-URI http://asc.fasb.org/extlink&oid=6584154&loc=d3e38371-112697

+ Details

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

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the fourth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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

- Definition

Amount of required minimum rental payments for operating leases having an initial or remaining non-cancelable lease term in excess of one year due after the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

+ Details

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