XML 247 R1.htm IDEA: XBRL DOCUMENT v3.19.1
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2019
Apr. 24, 2019
Document And Entity Information [Abstract]    
Entity Registrant Name FEDERATED INVESTORS INC /PA/  
Entity Central Index Key 0001056288  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Document Type 10-Q  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
Amendment Flag false  
Trading Symbol FII  
Entity Emerging Growth Company false  
Entity Small Business false  
Class A    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   9,000
Class B Shares    
Document Information [Line Items]    
Entity Common Stock, Shares Outstanding   101,217,123