Operating Segments and Geographic Information - Information on Reportable Segments (Details) $ in Millions	3 Months Ended	9 Months Ended
Mar. 31, 2018 USD ($)	Apr. 01, 2017 USD ($)	Mar. 31, 2018 USD ($) subsegment segment	Apr. 01, 2017 USD ($)
Information on reportable segments
Number of broad business categories (in segment) \| segment			2
Net revenue	$ 219.4	$ 196.0	$ 616.4	$ 613.3
Gross profit	$ 123.7	$ 117.0	$ 356.0	$ 366.8
Gross margin (as a percent)	56.40%	59.70%	57.80%	59.80%
Operating income	$ 0.4	$ (15.2)	$ 14.1	$ 1.6
Operating margin (as a percent)	0.20%	(7.80%)	2.30%	0.30%
Segment Measures
Information on reportable segments
Gross profit	$ 134.4	$ 121.9	$ 379.3	$ 382.1
Operating income	33.2	23.4	88.0	77.8
Other Items
Information on reportable segments
Net revenue	0.0	0.0	0.0	0.0
Gross profit	(10.7)	(4.9)	(23.3)	(15.3)
Operating income	(32.8)	(38.6)	$ (73.9)	(76.2)
Network and Service Enablement
Information on reportable segments
Number of subsegments (in subsegment) \| subsegment			2
Network and Service Enablement \| Segment Measures
Information on reportable segments
Net revenue	157.1	132.1	$ 451.5	444.7
Gross profit	$ 101.6	$ 85.2	$ 288.9	$ 285.6
Gross margin (as a percent)	64.70%	64.50%	64.00%	64.20%
Operating income	$ 9.6	$ (4.4)	$ 24.8	$ 5.7
Operating margin (as a percent)	6.10%	(3.30%)	5.50%	1.30%
Network and Service Enablement \| Network Enablement \| Segment Measures
Information on reportable segments
Net revenue	$ 127.0	$ 103.4	$ 360.3	$ 339.0
Gross profit	$ 80.9	$ 67.5	$ 225.3	$ 219.5
Gross margin (as a percent)	63.70%	65.30%	62.50%	64.70%
Network and Service Enablement \| Service Enablement \| Segment Measures
Information on reportable segments
Net revenue	$ 30.1	$ 28.7	$ 91.2	$ 105.7
Gross profit	$ 20.7	$ 17.7	$ 63.6	$ 66.1
Gross margin (as a percent)	68.80%	61.70%	69.70%	62.50%
Optical Security and Performance Products \| Segment Measures
Information on reportable segments
Net revenue	$ 62.3	$ 63.9	$ 164.9	$ 168.6
Gross profit	$ 32.8	$ 36.7	$ 90.4	$ 96.5
Gross margin (as a percent)	52.60%	57.40%	54.80%	57.20%
Operating income	$ 23.6	$ 27.8	$ 63.2	$ 72.1
Operating margin (as a percent)	37.90%	43.50%	38.30%	42.80%

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1,2)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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