Document And Entity Information	9 Months Ended
	Mar. 31, 2017 shares
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q3
Entity Registrant Name	ZAYO GROUP LLC
Entity Central Index Key	0001502756
Current Fiscal Year End Date	--06-30
Entity Filer Category	Non-accelerated Filer
Entity Current Reporting Status	Yes
Entity Common Stock, Shares Outstanding	0