Document And Entity Information	9 Months Ended
	Mar. 31, 2015	Apr. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2015
Entity Registrant Name	AUTOMATIC DATA PROCESSING INC
Entity Central Index Key	0000008670
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Entity Common Stock, Shares Outstanding		469,524,030