Operating Segments and Geographic Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 27, 2015 USD ($)	Mar. 28, 2015 USD ($)	Dec. 27, 2014 USD ($)	Sep. 27, 2014 USD ($) item	Jun. 28, 2014 USD ($)	Mar. 29, 2014 USD ($)	Dec. 28, 2013 USD ($)	Sep. 28, 2013 USD ($)	Jun. 27, 2015 USD ($) item	Jun. 28, 2014 USD ($)	Jun. 29, 2013 USD ($)
Net revenue:
Net Revenue									$ 1,709.1	$ 1,743.2	$ 1,676.9
Operating income (loss):
Total operating income									$ 149.1	150.8	145.8
Unallocated amounts:
Number of reporting units | item				2					2
Restructuring and related charges	$ (13.6)	$ (8.3)	$ (9.7)	$ (2.9)	$ (20.0)	$ (3.6)	$ (1.0)		$ (34.5)	(23.8)	(19.0)
Interest and other income (expense), net	2.2	0.3	0.4	0.5	0.1	0.6	0.4	$ (0.6)	3.4	0.5	(4.1)
Interest expense	(8.6)	(8.6)	(8.5)	(8.3)	(8.4)	(7.7)	(8.4)	(5.2)	(34.0)	(29.7)	(17.9)
Loss from continuing operations before income taxes	$ (32.4)	$ (30.6)	$ (16.3)	$ (3.6)	$ (24.8)	$ (18.7)	$ 11.8	$ 0.8	(82.9)	(30.9)	(46.9)
Corporate
Operating income (loss):
Total operating income									(88.6)	(95.0)	(92.9)
Segment Reconciling Items
Unallocated amounts:
Stock-based compensation									(66.9)	(64.1)	(56.4)
Amortization of intangibles									(59.2)	(59.0)	(76.0)
Loss on disposal of long-lived assets									(1.4)	(2.0)	(3.6)
Restructuring and related charges									(34.5)	(23.8)	(19.0)
Other charges related to non-recurring activities									(39.4)	(3.6)	(15.7)
Interest and other income (expense), net									3.4	0.5	(4.1)
Interest expense									(34.0)	(29.7)	(17.9)
Loss from continuing operations before income taxes									(82.9)	(30.9)	(46.9)
Network Enablement
Net revenue:
Net Revenue									532.2	602.4	571.7
Operating income (loss):
Total operating income									90.6	105.9	87.0
Service Enablement
Net revenue:
Net Revenue									169.0	145.9	157.2
Operating income (loss):
Total operating income									(18.0)	(25.6)	(3.9)
Communications and Commercial Optical Products
Net revenue:
Net Revenue									815.1	794.1	742.2
Operating income (loss):
Total operating income									90.2	93.5	82.4
Optical Security and Performance Products
Net revenue:
Net Revenue									192.8	200.8	205.8
Operating income (loss):
Total operating income									$ 74.9	$ 72.0	73.2
NE's Speed Wireline Product Line Exit
Unallocated amounts:
Write-downs of inventories											$ 11.3