Document And Entity Information - USD ($)
12 Months Ended
Apr. 30, 2018
May 31, 2018
Oct. 31, 2017
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Apr. 30, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Entity Registrant Name H&R BLOCK INC    
Entity Central Index Key 0000012659    
Current Fiscal Year End Date --04-30    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   209,255,308  
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 5,206,300,675