Finisar Acquisition - Allocation of Purchase Price Based on Estimated Fair Value of Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Jun. 30, 2020	Sep. 30, 2019
Previously Reported/As Adjusted
Goodwill	$ 1,254,338	$ 1,254,338	$ 1,239,009
Measurement Period Adjustments
Total Purchase Price	(6,500)
Finisar Corporation
Previously Reported/As Adjusted
Cash and cash equivalents	842,477	842,477		$ 842,764
Accounts receivable	259,341	259,341		260,864
Inventories	439,708	439,708		437,867
Property, plant & equipment	657,713	657,713		748,858
Intangible assets	665,200	665,200		827,689
Other assets	76,468	76,468		82,624
Deferred tax assets	16,267	16,267		0
Accounts payable	(123,707)	(123,707)		(123,707)
Other accrued liabilities	(195,588)	(195,588)		(148,425)
Deferred tax liabilities	(68,666)	(68,666)		(197,809)
Debt	(575,000)	(575,000)		(575,000)
Goodwill	914,290	914,290		759,239
Total Purchase Price	2,908,503	2,908,503		$ 2,914,964
Measurement Period Adjustments
Accounts receivable		(1,523)
Inventories		1,841
Property, plant & equipment		(91,145)
Intangibles assets		(162,489)
Other assets		(6,443)
Deferred tax assets		16,267
Other accrued liabilities		(3,199)
Deferred taxes liabilities		85,179
Goodwill		155,051
Total Purchase Price		(6,461)
Finisar Corporation | Reclassification Adjustments
Previously Reported/As Adjusted
Cash and cash equivalents	(287)	(287)
Other assets	287	287
Other accrued liabilities	(43,964)	(43,964)
Deferred tax liabilities	$ 43,964	$ 43,964