Fair Value Measurements (Narrative) (Details)	Nov. 30, 2011	Sep. 30, 2011
Fair Value Measurements [Abstract]
Agreements to purchase the remaining shares		25.00%
Percentage of shares owned	100.00%

Percentage of subsidiary's or equity investee's stock to be purchased by parent company as required by a purchase agreement.

No definition available.

Name:	apd_AgreementsToPurchaseRemainingShares
Namespace Prefix:	apd_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant