Document and Entity Information
3 Months Ended
Jun. 30, 2013
Aug. 02, 2013
Document Document And Entity Information [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2013  
Document Fiscal Year Focus 2014  
Document Fiscal Period Focus Q1  
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   49,567,819