| Component: (Network and Table) | |
|---|---|
| Network | 00090 - Document - Document And Entity Information (http://www.atmi.com/role/DocumentDocumentAndEntityInformation) |
| Table | (Implied) |
| Reporting Entity [Axis] | 0001041577 (http://www.sec.gov/CIK) |
| Document And Entity Information [Abstract] | Period [Axis] | ||
|---|---|---|---|
2012-01-01 - 2012-12-31 | 2013-01-31 | 2012-06-30 | |
Document And Entity Information [Abstract] | |||
Document Type | 10-K | ||
Amendment Flag | false | ||
Document Period End Date | 2012-12-31 | ||
Document Fiscal Year Focus | 2012 | ||
Document Fiscal Period Focus | FY | ||
Entity Registrant Name | ATMI INC | ||
Entity Central Index Key | 0001041577 | ||
Trading Symbol | atmi | ||
Current Fiscal Year End Date | --12-31 | ||
Entity Filer Category | Accelerated Filer | ||
Entity Well-known Seasoned Issuer | No | ||
Entity Current Reporting Status | Yes | ||
Entity Voluntary Filers | No | ||
Entity Public Float | 647,140,000 | ||
Entity Common Stock, Shares Outstanding | 31,986,318 | ||