v2.4.0.6
Document And Entity Information (USD $)
In Millions, except Share data, unless otherwise specified
12 Months Ended
Mar. 31, 2012
May 24, 2012
Sep. 30, 2011
Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Mar. 31, 2012    
Document Fiscal Year Focus 2012    
Document Fiscal Period Focus FY    
Trading Symbol exp    
Entity Registrant Name EAGLE MATERIALS INC    
Entity Central Index Key 0000918646    
Current Fiscal Year End Date --03-31    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   45,280,886  
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer Yes    
Entity Public Float     $ 706.1
Entity Current Reporting Status Yes