| Component: (Network and Table) | |
|---|---|
| Network | 2454409 - Disclosure - Employee Benefit Plans (Schedule of Estimated Future Benefit Payments) (Details) (http://www.alxn.com/role/EmployeeBenefitPlansScheduleOfEstimatedFutureBenefitPaymentsDetails) |
| Table | (Implied) |
| Reporting Entity [Axis] | 0000899866 (http://www.sec.gov/CIK) |
| Compensation and Retirement Disclosure [Abstract] | Period [Axis] |
|---|---|
2016-12-31 | |
Compensation and Retirement Disclosure [Abstract] | |
2017 | |
2018 | |
2019 | |
2020 | |
2021 | |
2022 to 2026 |