Segment Reporting - Schedule of Financial Information of Company's Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Sep. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Mar. 31, 2024	Mar. 31, 2023	Jun. 30, 2023
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	$ 1,208,809			$ 1,240,194			$ 3,393,326	$ 3,955,049
Inter-segment revenues	0			0			0	0
Operating income (loss)	22,305			67,388			32,882	118,110
Interest expense	(72,753)			(75,183)			(220,689)	(207,976)
Other income (expense), net	18,597			3,048			30,252	(32,253)
Income tax benefit	16,121			7,293			45,816	40,895
Net Earnings (Loss)	(15,730)	$ (28,475)	$ (67,534)	2,546	$ (45,072)	$ (38,698)	(111,739)	(81,224)
Net loss attributable to Coherent Corp.	(13,187)			2,546			(107,712)	(81,224)
Depreciation and amortization	139,735			160,941			416,113	478,136
Expenditures for property, plant & equipment	93,242			97,145			246,909	342,999
Segment assets	14,520,412			14,117,632			14,520,412	14,117,632	$ 13,711,133
Goodwill	4,493,225			4,505,137			4,493,225	4,505,137	4,512,700
Networking
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Goodwill	1,036,661						1,036,661		1,036,204
Materials
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Goodwill	247,919						247,919		247,695
Lasers
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Goodwill	3,208,645						3,208,645		$ 3,228,801
Operating Segments | Networking
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	618,824			551,099			1,615,908	1,756,327
Inter-segment revenues	10,892			17,759			33,758	54,129
Operating income (loss)	58,166			49,476			121,971	230,497
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	40,573			41,369			121,780	124,384
Expenditures for property, plant & equipment	20,884			6,441			74,751	80,654
Segment assets	3,497,693			3,435,816			3,497,693	3,435,816
Goodwill	1,036,661			1,012,006			1,036,661	1,012,006
Operating Segments | Materials
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	238,982			323,769			737,300	1,061,809
Inter-segment revenues	132,177			96,604			315,961	277,502
Operating income (loss)	8,220			67,826			25,173	224,633
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	26,508			29,242			77,205	83,804
Expenditures for property, plant & equipment	61,119			78,666			156,142	215,038
Segment assets	3,028,652			2,275,614			3,028,652	2,275,614
Goodwill	247,919			273,341			247,919	273,341
Operating Segments | Lasers
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	351,003			365,326			1,040,118	1,136,913
Inter-segment revenues	1,513			317			3,357	1,400
Operating income (loss)	(44,081)			(49,914)			(114,262)	(337,020)
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	72,654			90,330			217,128	269,948
Expenditures for property, plant & equipment	11,239			12,038			16,016	47,307
Segment assets	7,994,067			8,406,202			7,994,067	8,406,202
Goodwill	3,208,645			3,219,790			3,208,645	3,219,790
Unallocated & Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenues	0			0			0	0
Inter-segment revenues	(144,582)			(114,680)			(353,076)	(333,031)
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			0	0
Goodwill	$ 0			$ 0			$ 0	$ 0