Segment Reporting - Schedule of Financial Information of Company's Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022	Jun. 30, 2023
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	$ 1,131,434		$ 1,370,285		$ 2,184,517	$ 2,714,855
Inter-segment revenues	0		0		0	0
Operating income (loss)	31,885		8,246		10,577	50,722
Interest expense	(74,678)		(70,904)		(147,936)	(132,793)
Other income (expense), net	5,386		(3,696)		11,655	(35,301)
Income tax benefit	8,932		21,282		29,695	33,602
Net earnings (loss)	(28,475)	$ (67,534)	(45,072)	$ (38,698)	(96,009)	(83,770)
Net loss attributable to Coherent Corp.	(26,991)		(45,072)		(94,525)	(83,770)
Depreciation and amortization	138,019		169,909		276,378	317,195
Expenditures for property, plant & equipment	91,470		106,864		153,667	245,854
Segment assets	14,662,880				14,662,880		$ 13,711,133
Goodwill	4,566,010				4,566,010		4,512,700
Networking
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Goodwill	1,036,900				1,036,900		1,036,204
Materials
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Goodwill	249,290				249,290		247,695
Lasers
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Goodwill	3,279,820				3,279,820		$ 3,228,801
Operating Segments | Networking
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	524,235		608,680		997,084	1,205,228
Inter-segment revenues	9,979		17,630		22,866	36,370
Operating income (loss)	47,488		90,039		63,805	181,021
Interest expense	0		0		0	0
Other income (expense), net	0		0		0	0
Income tax benefit	0		0		0	0
Net earnings (loss)	0		0		0	0
Net loss attributable to Coherent Corp.	0				0
Depreciation and amortization	40,771		40,241		81,207	83,015
Expenditures for property, plant & equipment	36,374		30,383		53,867	74,213
Segment assets	3,383,786				3,383,786
Goodwill	1,036,900				1,036,900
Operating Segments | Materials
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	253,678		382,396		498,318	738,040
Inter-segment revenues	96,042		85,844		183,784	180,898
Operating income (loss)	9,771		81,472		16,953	156,807
Interest expense	0		0		0	0
Other income (expense), net	0		0		0	0
Income tax benefit	0		0		0	0
Net earnings (loss)	0		0		0	0
Net loss attributable to Coherent Corp.	0				0
Depreciation and amortization	25,410		28,035		50,697	54,562
Expenditures for property, plant & equipment	54,511		61,474		95,023	136,372
Segment assets	3,085,302				3,085,302
Goodwill	249,290				249,290
Operating Segments | Lasers
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	353,521		379,209		689,115	771,587
Inter-segment revenues	1,205		917		1,844	1,083
Operating income (loss)	(25,374)		(163,265)		(70,181)	(287,106)
Interest expense	0		0		0	0
Other income (expense), net	0		0		0	0
Income tax benefit	0		0		0	0
Net earnings (loss)	0		0		0	0
Net loss attributable to Coherent Corp.	0				0
Depreciation and amortization	71,838		101,633		144,474	179,618
Expenditures for property, plant & equipment	585		15,007		4,777	35,269
Segment assets	8,193,792				8,193,792
Goodwill	3,279,820				3,279,820
Unallocated & Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	0		0		0	0
Inter-segment revenues	(107,226)		(104,391)		(208,494)	(218,351)
Operating income (loss)	0		0		0	0
Interest expense	0		0		0	0
Other income (expense), net	0		0		0	0
Income tax benefit	0		0		0	0
Net earnings (loss)	0		0		0	0
Net loss attributable to Coherent Corp.	0				0
Depreciation and amortization	0		0		0	0
Expenditures for property, plant & equipment	0		$ 0		0	$ 0
Segment assets	0				0
Goodwill	$ 0				$ 0