Rendering

Component: (Network and Table)
Network
2440405 - Disclosure - Income Taxes (Reconciliation of the Statutory U.S. Federal Income Tax Rate to Effective Income Tax Rate) (Details)
(http://www.alxn.com/role/IncomeTaxesReconciliationOfStatutoryUSFederalIncomeTaxRateToEffectiveIncomeTaxRateDetails)
Table(Implied)
Slicers (applies to each fact value in each table cell)
Reporting Entity [Axis]0000899866 (http://www.sec.gov/CIK)
Income Tax Disclosure [Abstract]Period [Axis]
2012-01-01 - 2012-12-31
2011-01-01 - 2011-12-31
2010-01-01 - 2010-12-31
Income Tax Disclosure [Abstract]
 
 
 
U.S. federal statutory tax rate
.350  
.350  
.350  
State and local income taxes
.017  
.025  
.025  
Foreign income tax rate differential
(.067) 
(.094) 
(.049) 
Income tax credits
(.004) 
(.141) 
(.010) 
Foreign income subject to U.S. taxation
.002  
.034  
.016  
Stock option compensation
.007  
.010  
.013  
State tax incentives
(.011) 
.000  
.000  
Structuring related costs
.048  
.000  
.000  
Non-deductible acquistion related costs
.003  
.003  
.000  
Other nondeductible and permanent differences
.018  
.050  
.011  
Provision (benefit) attributable to valuation allowances
(.004) 
.000  
(.007) 
Effective income tax rate
.359  
 
.237  
 
.349