Document and Entity Information	3 Months Ended
	Jun. 30, 2013	Jul. 31, 2013
Document and Entity Information
Entity Registrant Name	AMERICAN SCIENCE & ENGINEERING, INC.
Entity Central Index Key	0000005768
Document Type	10-Q
Document Period End Date	Jun. 30, 2013
Amendment Flag	false
Current Fiscal Year End Date	--03-31
Entity Current Reporting Status	Yes
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		7,814,490
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q1