| Document and Entity Information | Oct. 27, 2021 |
| Document And Entity Information [Line Items] | |
| Entity Registrant Name | AIR PRODUCTS & CHEMICALS INC /DE/ |
| Amendment Flag | false |
| Entity Central Index Key | 0000002969 |
| Document Type | 8-K |
| Document Period End Date | Oct. 27, 2021 |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-04534 |
| Entity Tax Identification Number | 23-1274455 |
| Entity Address, Address Line One | 7201 Hamilton Boulevard |
| Entity Address, City or Town | Allentown |
| Entity Address, State or Province | PA |
| Entity Address, Postal Zip Code | 18195-1501 |
| City Area Code | (610) |
| Local Phone Number | 481-4911 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Common Stock [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Common Stock, par value $1.00 per share |
| Trading Symbol | APD |
| Security Exchange Name | NYSE |
| Euro Notes Due 2025 One Percent [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 1.000% Notes due 2025 |
| Trading Symbol | APD25 |
| Security Exchange Name | NYSE |
| A 0500 Notes Due 2028 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 0.500% Notes due 2028 |
| Trading Symbol | APD28 |
| Security Exchange Name | NYSE |
| A 0800 Notes Due 2032 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | 0.800% Notes due 2032 |
| Trading Symbol | APD32 |
| Security Exchange Name | NYSE |
