Debt - Components of Debt (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Sep. 30, 2020	Dec. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Total debt		$ 1,470,840	$ 2,255,342
Current portion of long-term debt		(62,050)	(69,250)
Long-term debt, less current portion		$ 1,408,790	2,186,092
0.50% Convertible Senior Notes
Line of Credit Facility [Line Items]
Debt instrument, interest rate		0.50%
Total debt, gross		$ 14,900
0.50% Convertible Senior Notes | Finisar Corporation
Line of Credit Facility [Line Items]
Total debt, gross		$ 14,888	14,888
0.25% Convertible Senior Notes due 2022
Line of Credit Facility [Line Items]
Debt instrument, interest rate		0.25%		0.25%
Total debt, gross		$ 345,000	345,000
0.25% convertible senior notes unamortized discount attributable to cash conversion option and debt issuance costs including initial purchaser discount		(23,835)	(30,688)
Term A Loan Facility
Line of Credit Facility [Line Items]
Total debt, gross		$ 1,163,438	1,194,463
Term A Loan Facility | LIBOR
Line of Credit Facility [Line Items]
Debt instrument, rate added on variable rate		1.50%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Total debt, gross		$ 0	74,000
Revolving Credit Facility | LIBOR
Line of Credit Facility [Line Items]
Debt instrument, rate added on variable rate		1.50%
Term A Facility and Revolving Credit Facility
Line of Credit Facility [Line Items]
Credit facility unamortized debt issuance costs		$ (28,651)	(32,174)
Term B Loan Facility
Line of Credit Facility [Line Items]
Total debt, gross		0	714,600
Credit facility unamortized debt issuance costs		$ 0	$ (24,747)
Term B Loan Facility | LIBOR
Line of Credit Facility [Line Items]
Debt instrument, rate added on variable rate	3.50%