Operating Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 02, 2016 USD ($)	Mar. 28, 2015 USD ($)	Apr. 02, 2016 USD ($) segment subsegment	Mar. 28, 2015 USD ($)
Information on reportable segments
Number of broad business categories (in segment) | segment			2
Net revenue	$ 220.4	$ 212.4	$ 682.2	$ 654.1
Gross profit	$ 131.3	$ 127.0	$ 413.6	$ 389.0
Gross margin (as a percent)	59.60%	59.80%	60.60%	59.50%
Operating income (loss)	$ 7.2	$ (23.2)	$ 13.5	$ (56.8)
Operating margin (as a percent)	3.30%	(10.90%)	2.00%	(8.70%)
Segment Measures
Information on reportable segments
Net revenue	$ 220.4	$ 212.4	$ 682.2	$ 654.1
Gross profit	$ 136.4	$ 137.7	$ 430.4	$ 419.7
Gross margin (as a percent)	61.90%	64.80%	63.10%	64.20%
Operating income (loss)	$ 26.2	$ 19.0	$ 85.4	$ 51.1
Operating margin (as a percent)	11.90%	8.90%	12.50%	7.80%
Reconciling Items
Information on reportable segments
Net revenue	$ 0.0	$ 0.0	$ 0.0	$ 0.0
Gross profit	(5.1)	(10.7)	(16.8)	(30.7)
Operating income (loss)	(19.0)	(42.2)	$ (71.9)	(107.9)
Network and Service Enablement
Information on reportable segments
Number of subsegment (in subsegment) | subsegment			2
Network and Service Enablement | Segment Measures
Information on reportable segments
Net revenue	158.3	164.0	$ 497.1	511.8
Gross profit	$ 100.5	$ 111.4	$ 324.7	$ 343.6
Gross margin (as a percent)	63.50%	67.90%	65.30%	67.10%
Operating income (loss)	$ (0.1)	$ 1.7	$ 10.3	$ 2.4
Operating margin (as a percent)	(0.10%)	1.00%	2.10%	0.50%
Network Enablement | Segment Measures
Information on reportable segments
Net revenue	$ 123.1	$ 124.1	$ 377.1	$ 374.6
Gross profit	$ 80.7	$ 83.2	$ 247.0	$ 248.0
Gross margin (as a percent)	65.60%	67.00%	65.50%	66.20%
Service Enablement | Segment Measures
Information on reportable segments
Net revenue	$ 35.2	$ 39.9	$ 120.0	$ 137.2
Gross profit	$ 19.8	$ 28.2	$ 77.7	$ 95.6
Gross margin (as a percent)	56.30%	70.70%	64.80%	69.70%
Optical Security and Performance Products | Segment Measures
Information on reportable segments
Net revenue	$ 62.1	$ 48.4	$ 185.1	$ 142.3
Gross profit	$ 35.9	$ 26.3	$ 105.7	$ 76.1
Gross margin (as a percent)	57.80%	54.30%	57.10%	53.50%
Operating income (loss)	$ 26.3	$ 17.3	$ 75.1	$ 48.7
Operating margin (as a percent)	42.40%	35.70%	40.60%	34.20%