Debt - Additional Information (Details)		1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Sep. 24, 2019	Aug. 31, 2017 USD ($) d $ / shares	Jun. 30, 2021 USD ($) d	Dec. 31, 2020 USD ($)	Jun. 30, 2021 USD ($) d	Jun. 30, 2020 USD ($)	Jun. 30, 2019
Line of Credit Facility [Line Items]
Aggregate principal outstanding			$ 1,417,270,000		$ 1,417,270,000
Debt instrument, unamortized discount			58,000,000		58,000,000
Available credit under lines of credit			$ 449,000,000		$ 449,000,000
Weighted average interest rate of total borrowings			1.00%		1.00%	3.00%
0.25% Convertible Senior Note Due 2022
Line of Credit Facility [Line Items]
Debt instrument, interest rate			0.25%		0.25%
Aggregate principal amount		$ 345,000,000
Aggregate principal outstanding			$ 344,969,000		$ 344,969,000	$ 345,000,000
Debt instrument conversion, shares issued per $1,000 principal amount		0.02125
Debt instrument, unamortized discount			$ 15,000,000		15,000,000
Debt instrument conversion, conversion price per share | $ / shares		$ 47.06
Debt instrument conversion, If-converted value of notes					$ 532,000,000	$ 346,000,000
Number of days within 30 consecutive trading days in which the closing price of the entity's common stock must exceed the conversion price for the notes to be convertible into common stock | d		20	20
Number of consecutive trading days during which the closing price of the entity's common stock must exceed the conversion price for at least 20 days in order for the notes to be convertible into common stock | d		30	30
Percentage of the closing sales price of the entity's common stock that the conversion price must exceed in order for the notes to be convertible		130.00%	130.00%
Business day period		5 days
Measurement period		5 days
Measurement period percentage		98.00%
Effective interest rate			5.00%		5.00%	5.00%	5.00%
0.50% Finisar Convertible Notes
Line of Credit Facility [Line Items]
Obligated to repay outstanding principal in quarterly installments, percentage	100.00%
Debt instrument, interest rate			0.50%		0.50%
Bank of America, N.A.
Line of Credit Facility [Line Items]
Letter of credit sub-facility maximum borrowing capacity			$ 25,000,000		$ 25,000,000
Swing loan sub-facility maximum initial borrowing capacity			20,000,000		20,000,000
Senior Secured Credit Facility | Bank of America, N.A.
Line of Credit Facility [Line Items]
Aggregate principal amount			2,400,000,000		2,400,000,000
Term A Loan Facility
Line of Credit Facility [Line Items]
Aggregate principal outstanding			1,057,412,000		1,057,412,000	$ 1,194,463,000
Term A Loan Facility | Bank of America, N.A.
Line of Credit Facility [Line Items]
Aggregate principal amount			1,255,000,000		$ 1,255,000,000
Debt instrument term					5 years
Obligated to repay outstanding principal in quarterly installments, percentage					1.25%
Term B Loan Facility
Line of Credit Facility [Line Items]
Cash paid for interest				$ 1,000,000
Debt issuance costs					$ 25,000,000
Aggregate principal outstanding			0		0	714,600,000
Term B Loan Facility | Bank of America, N.A.
Line of Credit Facility [Line Items]
Aggregate principal amount			720,000,000		$ 720,000,000
Debt instrument term					7 years
Revolving Credit Facility
Line of Credit Facility [Line Items]
Aggregate principal outstanding			0		$ 0	$ 74,000,000
Revolving Credit Facility | Bank of America, N.A.
Line of Credit Facility [Line Items]
Aggregate principal amount			$ 450,000,000		$ 450,000,000
Debt instrument term					5 years
New Senior Credit Facilities | Fifth Fiscal Quarter Through Eighth Fiscal Quarter After Closing Date
Line of Credit Facility [Line Items]
Leverage ratio					4.50
New Senior Credit Facilities | Subsequent Fiscal Quarter
Line of Credit Facility [Line Items]
Leverage ratio					4.00
New Senior Credit Facilities | Minimum
Line of Credit Facility [Line Items]
Interest coverage ratio					3.00
New Senior Credit Facilities | Maximum | First Four Fiscal Quarters After Closing Date
Line of Credit Facility [Line Items]
Leverage ratio					5.00
New Senior Credit Facilities | Federal Funds Rate
Line of Credit Facility [Line Items]
Debt instrument, rate added on variable rate					0.50%
New Senior Credit Facilities | Euro Rate Option
Line of Credit Facility [Line Items]
Debt instrument, rate added on variable rate					1.00%
New Senior Credit Facilities | 0.25% Convertible Senior Note Due 2022 | II-VI Notes
Line of Credit Facility [Line Items]
Number of days prior to maturity of outstanding | d					120
Debt instrument, interest rate			0.25%		0.25%