Segment and Geographic Reporting - Schedule of Capital Expenditures, Depreciation and Amortization by Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Expenditures for property, plant & equipment	$ 440,836	$ 346,816	$ 436,060
Depreciation and amortization	553,598	559,761,000	681,687,000
Operating Segments \| Networking
Segment Reporting Information [Line Items]
Expenditures for property, plant & equipment	263,425	90,950	98,192
Depreciation and amortization	162,225	158,833,000	169,573,000
Operating Segments \| Materials
Segment Reporting Information [Line Items]
Expenditures for property, plant & equipment	137,444	224,482	274,434
Depreciation and amortization	119,118	107,798,000	141,648,000
Operating Segments \| Lasers
Segment Reporting Information [Line Items]
Expenditures for property, plant & equipment	39,967	31,384	63,434
Depreciation and amortization	267,328	287,662,000	364,370,000
Corporate and shared services
Segment Reporting Information [Line Items]
Depreciation and amortization	$ 4,927	$ 5,468,000	$ 6,096,000