Document and Entity Information (USD $)	12 Months Ended
	Jun. 30, 2014	Aug. 06, 2014	Dec. 31, 2013
Document and Entity Information
Entity Registrant Name	ASPEN TECHNOLOGY INC /DE/
Entity Central Index Key	0000929940
Document Type	10-K
Document Period End Date	Jun. 30, 2014
Amendment Flag	false
Current Fiscal Year End Date	--06-30
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 3,466,534,401
Entity Common Stock, Shares Outstanding		91,269,545
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY