| Component: (Network and Table) | |
|---|---|
| Network | 159 - Disclosure - Assumptions Used to Value Options Granted (Detail) (http://www.achillion.com/taxonomy/role/DisclosureAssumptionsUsedToValueOptionsGranted) |
| Table | Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] |
| Reporting Entity [Axis] | 0001070336 (http://www.sec.gov/CIK) |
| Legal Entity [Axis] | Entity [Domain] |
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | Period [Axis] | ||||||||
|---|---|---|---|---|---|---|---|---|---|
2016-01-01 - 2016-12-31 | 2015-01-01 - 2015-12-31 | 2014-01-01 - 2014-12-31 | |||||||
| Range [Axis] | Range [Axis] | Range [Axis] | |||||||
| Minimum | Maximum | Range [Domain] | Minimum | Maximum | Range [Domain] | Minimum | Maximum | Range [Domain] | |
Expected term of option | |||||||||
Expected dividend yield | |||||||||
Expected volatility | |||||||||
Risk free interest rate | |||||||||