Income Taxes (Narratives) (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating Loss Carryforwards [Line Items]
Provision for income taxes	$ 1,675	$ 907
Unrecognized tax benefits	19,200
Unrecognized tax benefit future impact if recognized	19,200
Enterasys, Zebra WLAN Business and Avaya Networking
Operating Loss Carryforwards [Line Items]
Tax amortization deduction for capitalized goodwill	1,600	$ 1,100
Deferred tax liability, goodwill	$ 6,900
Amortization period for tax purposes	15 years