Debt (Narratives) (Details) - USD ($)					12 Months Ended
	May 01, 2018	Oct. 26, 2017	Jul. 14, 2017	Oct. 28, 2016	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Line Of Credit Facility [Line Items]
Loss on extinguishment of debt					$ 1,173,000
Outstanding letters of credit					1,300,000
Interest Expense
Line Of Credit Facility [Line Items]
Amortization of deferred financing costs					700,000	$ 500,000	$ 400,000
Credit Facility | Campus Fabric Business
Line Of Credit Facility [Line Items]
Borrowing capacity from Credit Agreement				$ 140,500,000
Credit Facility | Term Loan
Line Of Credit Facility [Line Items]
Credit Facility, term				5 years
Amount borrowed under Term Loan				$ 90,500,000
Credit Facility | Revolving Facility
Line Of Credit Facility [Line Items]
Credit Facility, term				5 years
Borrowing capacity from Credit Agreement				$ 50,000,000
Credit Facility | Revolving Facility | Swing Line Loan Sub Facility
Line Of Credit Facility [Line Items]
Borrowing capacity from Credit Agreement				5,000,000
Credit Facility | Revolving Facility | Letter of Credit Sub Facility
Line Of Credit Facility [Line Items]
Borrowing capacity from Credit Agreement				$ 10,000,000
Second Amendment
Line Of Credit Facility [Line Items]
Termination date	May 01, 2018
Second Amendment | Campus Fabric Business
Line Of Credit Facility [Line Items]
Borrowing capacity from Credit Agreement			$ 243,700,000
Second Amendment | Maximum | Campus Fabric Business
Line Of Credit Facility [Line Items]
Additional incremental loan facility			$ 50,000,000
Second Amendment | Term Loan | Campus Fabric Business
Line Of Credit Facility [Line Items]
Credit Facility, term			5 years
Amount borrowed under Term Loan			$ 183,700,000
Increase in borrowing under Term Loan			$ 80,000,000
Second Amendment | Revolving Facility | Campus Fabric Business
Line Of Credit Facility [Line Items]
Credit Facility, term			5 years
Borrowing capacity from Credit Agreement			$ 60,000,000
Third Amendment | Amended Term Loan | Data Center Business
Line Of Credit Facility [Line Items]
Borrowings under Term Loan		$ 20,000,000
Credit Agreement
Line Of Credit Facility [Line Items]
Borrowings under Term Loan	$ 200,000,000
Deferred financing costs					1,500,000
Credit Agreement | Interest Expense
Line Of Credit Facility [Line Items]
Loss on extinguishment of debt					$ 1,200,000
Credit Agreement | Maximum
Line Of Credit Facility [Line Items]
Additional incremental loan facility	$ 100,000,000
Credit Agreement | Maximum | London Interbank Offered Rate (LIBOR)
Line Of Credit Facility [Line Items]
Borrowings, interest rate					2.75%
Credit Agreement | Maximum | Adjusted Base Rate
Line Of Credit Facility [Line Items]
Borrowings, interest rate					1.75%
Credit Agreement | Minimum | London Interbank Offered Rate (LIBOR)
Line Of Credit Facility [Line Items]
Borrowings, interest rate					1.50%
Credit Agreement | Minimum | Adjusted Base Rate
Line Of Credit Facility [Line Items]
Borrowings, interest rate					0.50%
Credit Agreement | Term Loan
Line Of Credit Facility [Line Items]
Credit Facility, term	5 years
Amount borrowed under Term Loan	$ 190,000,000
Credit Agreement | Revolving Facility
Line Of Credit Facility [Line Items]
Credit Facility, term	5 years
Borrowing capacity from Credit Agreement	$ 40,000,000
Commitment fee					0.35%
Borrowings available under facility					$ 28,700,000
Credit Agreement | Revolving Facility | Maximum
Line Of Credit Facility [Line Items]
Commitment fee					0.40%
Credit Agreement | Revolving Facility | Minimum
Line Of Credit Facility [Line Items]
Commitment fee					0.25%