Debt - Additional Information (Detail)			1 Months Ended	3 Months Ended	6 Months Ended			12 Months Ended
	Oct. 23, 2019 USD ($)	Sep. 24, 2019 USD ($)	Aug. 31, 2017 USD ($) d $ / shares	Dec. 31, 2020 USD ($) d	Dec. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) d	Dec. 31, 2019 USD ($)	Jun. 30, 2020 USD ($)
Line of Credit Facility [Line Items]
Cash paid for interest						$ 13,898,000	$ 24,745,000
Available credit under lines of credit				$ 448,600,000	$ 448,600,000	$ 448,600,000
Weighted average interest rate of total borrowings				1.70%	1.70%	1.70%	3.80%
0.25% Convertible Senior Notes due 2022
Line of Credit Facility [Line Items]
Debt instrument, interest rate				0.25%	0.25%	0.25%	0.25%
Aggregate principal amount			$ 345,000,000
Aggregate principal outstanding				$ 345,000,000	$ 345,000,000	$ 345,000,000		$ 345,000,000
Debt instrument, conversion ratio			0.02125
Debt instrument conversion, conversion price per share (in usd per share) | $ / shares			$ 47.06
Debt instrument conversion, If-converted value of notes						$ 556,900,000		$ 346,200,000
Debt instrument conversion, trading days | d			20	20
Debt instrument conversion, consecutive trading days | d			30	30
Debt instrument conversion, conversion price percentage			130.00%	130.00%
Debt instrument conversion, business day period			5 days
Debt instrument conversion, measurement period			5 days
Debt instrument conversion, measurement period percentage			98.00%
Effective interest rate				4.50%	4.50%	4.50%		4.50%
Unamortized discount amount				$ 20,800,000	$ 20,800,000	$ 20,800,000
Amortization period						3 years
0.50% Finisar Convertible Notes
Line of Credit Facility [Line Items]
Redemption price percentage		100.00%				100.00%
Debt instrument, interest rate				0.50%	0.50%	0.50%
Aggregate principal amount		$ 560,100,000
Debt instrument, repurchase amount	$ 561,100,000
Aggregate principal outstanding				$ 14,900,000	$ 14,900,000	$ 14,900,000
Bank of America, N.A.
Line of Credit Facility [Line Items]
Letter of credit sub-facility maximum borrowing capacity				25,000,000.0	25,000,000.0	25,000,000.0
Swing loan sub-facility maximum initial borrowing capacity				20,000,000.0	20,000,000.0	20,000,000.0
Senior Secured Credit Facility | Bank of America, N.A.
Line of Credit Facility [Line Items]
Aggregate principal amount				2,425,000,000	2,425,000,000	2,425,000,000
Term A Loan Facility
Line of Credit Facility [Line Items]
Proceeds from term loan	$ 561,000,000.0
Aggregate principal outstanding				1,163,438,000	1,163,438,000	1,163,438,000		$ 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	$ 1,255,000,000
Debt agreement term						5 years
Redemption price percentage						1.25%
Term B Loan Facility
Line of Credit Facility [Line Items]
Aggregate principal amount				720,000,000	720,000,000	$ 720,000,000
Debt agreement term						7 years
Cash paid for interest						$ 600,000
Debt issuance costs					24,700,000
Aggregate principal outstanding				0	0	0		714,600,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Aggregate principal outstanding				0	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	$ 450,000,000
Debt agreement term						5 years
Senior Credit Facilities | Fifth Fiscal Quarter Through Eighth Fiscal Quarter After Closing Date
Line of Credit Facility [Line Items]
Leverage ratio						4.50
Senior Credit Facilities | Subsequent Fiscal Quarter
Line of Credit Facility [Line Items]
Leverage ratio						4.00
Senior Credit Facilities | Minimum
Line of Credit Facility [Line Items]
Interest coverage ratio						3.00
Senior Credit Facilities | Maximum | First Four Fiscal Quarters After Closing Date
Line of Credit Facility [Line Items]
Leverage ratio						5.00
Senior Credit Facilities | Federal Funds Rate
Line of Credit Facility [Line Items]
Debt instrument, rate added on variable rate						0.50%
Senior Credit Facilities | Eurodollar
Line of Credit Facility [Line Items]
Debt instrument, rate added on variable rate						1.00%
Senior Credit Facilities | 0.25% Convertible Senior Notes due 2022 | I I V I 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%	0.25%