Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		1 Months Ended	3 Months Ended								11 Months Ended	12 Months Ended
	Aug. 01, 2015	Aug. 01, 2015	Jul. 02, 2016	Apr. 02, 2016	Dec. 26, 2015	Sep. 26, 2015	Jun. 27, 2015	Mar. 28, 2015	Dec. 27, 2014	Sep. 27, 2014	Jul. 02, 2016	Jul. 02, 2016		Jun. 27, 2015		Jun. 28, 2014
Numerator:
Net income (loss)			$ 14.3	$ (7.6)	$ 2.8	$ (0.2)	$ (15.8)	$ 12.2	$ (4.1)	$ 4.3		$ 9.3		$ (3.4)		$ 10.7
Less: Cumulative dividends on Series A Preferred Stock												(0.8)		0.0		0.0
Less: Accretion of Series A Preferred Stock												(11.7)		0.0		0.0
Net income (loss) attributable to common stockholders		$ (11.7)									$ 21.0	$ (3.2)		$ (3.4)		$ 10.7
Denominator
Basic (in shares)			59.4	59.2	59.0	58.8	58.8	58.8	58.8	58.8		59.1	[1]	58.8	[1]	58.8	[1]
Effect of dilutive securities from stock-based benefit plans (in shares)												0.0		0.0		0.0
Diluted (in shares)			61.8	59.2	59.2	58.8	58.8	58.8	58.8	58.8		59.1	[1]	58.8	[1]	58.8	[1]
Basic (usd per share)			$ 0.24	$ (0.13)	$ 0.05	$ 0.00	$ (0.27)	$ 0.21	$ (0.07)	$ 0.07		$ (0.05)	[1]	$ (0.06)	[1]	$ 0.18	[1]
Diluted (usd per share)			$ 0.23	$ (0.13)	$ 0.05	$ 0.00	$ (0.27)	$ 0.21	$ (0.07)	$ 0.07		$ (0.05)	[1]	$ (0.06)	[1]	$ 0.18	[1]
Shares distributed during period (in shares)	47.1
Percentage of outstanding shares distributed	80.10%
Weighted average shares were excluded from the calculation of diluted shares ( in shares)												1.2

[1] On August 1, 2015, JDS Uniphase Corporation (“JDSU”) distributed 47.1 million shares, or 80.1% of the outstanding shares of common stock of Lumentum Holdings Inc. (“Lumentum”) to existing holders of JDSU common stock. JDSU was renamed Viavi Solutions Inc. (“Viavi”) and at the time of the distribution, retained 11.7 million shares, or 19.9% of Lumentum’s outstanding shares. Basic and diluted net income (loss) per share for all periods through June 27, 2015 is calculated using the shares of Lumentum common stock outstanding on August 1, 2015. Refer to "Note 4. Earnings Per Share" in the Notes to Consolidated Financial Statements.