Document And Entity Information - USD ($)	12 Months Ended
	Jun. 30, 2015	Aug. 14, 2015	Dec. 31, 2014
Document Information [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Entity Registrant Name	PAREXEL INTERNATIONAL CORP
Entity Central Index Key	0000799729
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		55,338,272
Entity Current Reporting Status	Yes
Entity Public Float			$ 3,012,000,000
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No