Financial Information of Company's Operation by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2019
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	$ 666,331	$ 342,839	$ 1,006,740	$ 657,272
Operating income (loss)	(78,580)	39,606	(97,054)	76,819
Interest expense	(28,390)	(5,580)	(35,358)	(11,164)
Other income (expense), net	(487)	701	(5,566)	1,414
Income taxes	9,242	(6,025)	13,766	(12,218)
Net earnings (loss)	(98,213)	28,702	(124,211)	54,851
Depreciation and amortization	82,152	22,329	109,100	44,499
Expenditures for property, plant & equipment	54,652	38,468	80,288	73,386
Segment assets	5,208,209		5,208,209		$ 1,953,773
Goodwill	1,096,691		1,096,691		319,778
Photonic Solutions
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	460,393	159,694	601,749	294,850
Inter-segment revenues	22,190	2,504	24,840	7,726
Operating income (loss)	(60,937)	23,087	(47,913)	38,999
Depreciation and amortization	55,174	6,462	61,990	12,661
Expenditures for property, plant & equipment	21,313	11,223	30,702	23,274
Segment assets	3,194,032		3,194,032
Goodwill	847,403		847,403		134,057
Compound Semiconductors
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues	205,938	183,145	382,940	362,422
Inter-segment revenues	66,123	17,538	80,056	34,708
Operating income (loss)	(8,835)	23,622	17,686	44,923
Depreciation and amortization	26,978	15,867	43,367	31,838
Expenditures for property, plant & equipment	33,339	27,246	46,822	50,113
Segment assets	2,014,177		2,014,177
Goodwill	249,288		249,288		$ 185,721
Unallocated & Other
Segment Reporting Reconciling Item For Operating Profit Loss From Segment To Consolidated [Line Items]
Revenues			22,051
Inter-segment revenues	(88,313)	(20,041)	(104,896)	(42,434)
Operating income (loss)	$ (8,808)	$ (7,103)	(66,827)	$ (7,103)
Depreciation and amortization			3,743
Expenditures for property, plant & equipment			$ 2,764