Summary of Significant Accounting Policies (Narratives) (Details) (USD $)	12 Months Ended									12 Months Ended		0 Months Ended	12 Months Ended	0 Months Ended					12 Months Ended	0 Months Ended	3 Months Ended	12 Months Ended			2 Months Ended	12 Months Ended
	Jun. 30, 2014 Distribution_Channels Investment_Securities	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2014 Minimum	Jun. 30, 2014 Maximum	Jun. 30, 2014 Product	Jun. 30, 2013 Product	Jun. 30, 2014 Services	Jun. 30, 2013 Services	Jun. 30, 2014 Available-for-sale Securities Government and Corporate Debt Securities	Jun. 30, 2014 Marketable Securities Minimum	Oct. 31, 2013 Revolving Credit Facility	Jun. 30, 2014 Revolving Credit Facility	Oct. 31, 2013 Term Loan Facility	Oct. 31, 2013 Senior Secured Credit Facilities [Member]	Oct. 31, 2013 Senior Secured Credit Facilities [Member] Minimum	Oct. 31, 2013 Senior Secured Credit Facilities [Member] Maximum	Oct. 31, 2013 Federal Funds Effective Rate Senior Secured Credit Facilities [Member]	Jun. 30, 2014 Enterasys Networks, Inc.	Oct. 31, 2013 Enterasys Networks, Inc. Revolving Credit Facility	Jun. 30, 2014 Enterasys Networks, Inc. Revolving Credit Facility	Jun. 30, 2014 Cost Of Product Revenue	Jun. 30, 2013 Cost Of Product Revenue	Jun. 30, 2012 Cost Of Product Revenue	Aug. 27, 2014 Subsequent Event Revolving Credit Facility	Jun. 30, 2014 Buildings	Jun. 30, 2014 Computer Equipment Minimum	Jun. 30, 2014 Computer Equipment Maximum	Jun. 30, 2014 Purchased Software Minimum	Jun. 30, 2014 Purchased Software Maximum	Jun. 30, 2014 Office Equipment Minimum	Jun. 30, 2014 Office Equipment Maximum	Jun. 30, 2014 Furniture and Fixtures Minimum	Jun. 30, 2014 Furniture and Fixtures Maximum	Jun. 30, 2014 Leasehold Improvements Minimum	Jun. 30, 2014 Leasehold Improvements Maximum
Significant Accounting Policies [Line Items]
Deferred revenue from customers other than distributors						$ 4,100,000	$ 3,100,000
Deferred product revenue from customers other than distributors	97,677,000	41,454,000						97,700,000	38,700,000
Number of distribution channels	2
Inventory, net	57,109,000	16,167,000
Inventory write-down		800,000	1,100,000
Maturity period for investments (in months and years)										3 years	1 year
Number of securities with unrealized losses (in securities)	2
Number of investment securities (in securities)	18
Other-than-temporary impairment loss	158,000
Long-term debt, carrying amount	121,600,000
Long-term debt, estimated fair value	121,300,000
Estimated useful lives of property and equipment																										25 years	1 year	4 years	1 year	4 years	5 years	7 years	5 years	7 years	2 years	10 years
Increase in property and equipment for asset retirement obligations																			1,200,000
Goodwill	70,877,000	0
Amortization expense	28,800,000																					11,900,000	1,500,000	1,800,000
Service inventory held to support customers	11,400,000	6,300,000
Extended warranty contracts period (in years)				1 year	5 years
Borrowing capacity from Credit Agreement												60,000,000		65,000,000
Credit Agreement term												5 years		5 years
Draw downs from Revolving Facility																				35,000,000	48,000,000
Repayments to Revolving Facility													24,000,000												24,000,000
Basis spread on Senior Secured Credit Facilities																		0.50%
Commitment fee percentage															0.50%	0.375%	0.50%
Deferred financing costs	1,300,000
Amortization of deferred financing costs	200,000
Outstanding letters of credit	900,000
Standard hardware warranty period (in months)	12 months
Standard software warranty period (in days)	90 days
Limited lifetime hardware warranty maximum period after end of sale of product (in years)	5 years
Advertising expenses	$ 500,000	$ 200,000	$ 500,000