Commitments And Contingencies (Agreement To Purchase Shares In Equity Affiliate) (Narrative) (Details)	Sep. 30, 2011
Schedule of Equity Method Investments [Line Items]
Percentage ownership to be purchased	25.00%
Abdullah Hashim Group [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership to be purchased	25.00%

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