Segment Reporting - Financial Information of Company's Operation by Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	$ 786,569	$ 666,331	$ 1,514,653	$ 1,006,740
Inter-segment revenues	0	0	0	0
Operating income (loss)	118,716	(78,580)	219,845	(97,054)
Interest expense	(15,585)	(28,390)	(32,799)	(35,358)
Other income (expense), net	3,153	(487)	(21,186)	(5,566)
Income taxes	(18,383)	9,242	(31,694)	13,766
Net earnings (loss)	87,900	(98,213)	134,166	(124,211)
Depreciation and amortization	67,200	82,152	131,886	109,100
Expenditures for property, plant & equipment	45,537	54,652	79,329	80,288
Segment assets	5,646,563		5,646,563		$ 5,234,714
Goodwill	1,292,384		1,292,384		1,239,009
Unallocated & Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	0	0	0	22,051
Inter-segment revenues	(73,253)	(88,313)	(147,556)	(104,896)
Operating income (loss)	0	(8,808)	0	(66,827)
Interest expense	0	0	0	0
Other income (expense), net	0	0	0	0
Income taxes	0	0	0	0
Net earnings (loss)	0	0	0	0
Depreciation and amortization	0	0	0	3,743
Expenditures for property, plant & equipment	0	0	0	2,764
Segment assets	0		0
Goodwill	0		0
Photonic Solutions
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Goodwill	240,552		240,552		186,515
Photonic Solutions | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	482,879	460,393	980,606	601,749
Inter-segment revenues	8,441	22,190	15,657	24,840
Operating income (loss)	48,439	(60,937)	98,873	(47,913)
Interest expense	0	0	0	0
Other income (expense), net	0	0	0	0
Income taxes	0	0	0	0
Net earnings (loss)	0	0	0	0
Depreciation and amortization	39,764	55,174	78,451	61,990
Expenditures for property, plant & equipment	24,853	21,313	46,087	30,702
Segment assets	3,700,184		3,700,184
Goodwill	1,051,832		1,051,832
Compound Semiconductors
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Goodwill	1,051,832		1,051,832		$ 1,052,494
Compound Semiconductors | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	303,690	205,938	534,047	382,940
Inter-segment revenues	64,812	66,123	131,899	80,056
Operating income (loss)	70,277	(8,835)	120,972	17,686
Interest expense	0	0	0	0
Other income (expense), net	0	0	0	0
Income taxes	0	0	0	0
Net earnings (loss)	0	0	0	0
Depreciation and amortization	27,437	26,978	53,435	43,367
Expenditures for property, plant & equipment	20,684	$ 33,339	33,242	$ 46,822
Segment assets	1,946,379		1,946,379
Goodwill	$ 240,552		$ 240,552