v2.4.0.6
Document and Entity Information (USD $)
12 Months Ended
Dec. 31, 2011
Feb. 23, 2012
Jun. 30, 2011
Document and Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2011    
Entity Registrant Name Employers Holdings, Inc.    
Entity Central Index Key 0001379041    
Current Fiscal Year End Date --12-31    
Entity Well Know Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock Shares Outstanding   32,596,685  
Entity Public Float     $ 634,835,041
Document Fiscal Year Focus 2011    
Document Fiscal Period Focus FY