Business Segments - Schedule of Results of Operation, Depreciation and Amortization, Capital Expenditures and Total Assets by Reportable Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Jun. 30, 2023
Net Sales
Total net sales	$ 684.9	$ 690.1	$ 1,961.1	$ 1,792.1
Operating Income
Consolidated operating income	75.9	39.3	214.8	70.2
Depreciation and Amortization
Consolidated depreciation and amortization	34.1	32.8	100.8	97.5
Capital Expenditures
Consolidated capital expenditures	21.6	20.5	68.9	51.5
Total Assets
Consolidated total assets	3,176.2		3,176.2		$ 3,053.9
Operating | Specialty Alloys Operations
Net Sales
Total net sales	608.5	603.4	1,728.0	1,546.6
Operating Income
Consolidated operating income	103.5	49.0	267.6	99.1
Depreciation and Amortization
Consolidated depreciation and amortization	28.8	27.5	85.0	81.9
Capital Expenditures
Consolidated capital expenditures	17.6	18.0	56.6	45.4
Total Assets
Consolidated total assets	2,558.3		2,558.3		2,461.2
Operating | Performance Engineered Products
Net Sales
Total net sales	102.4	115.1	299.9	315.1
Operating Income
Consolidated operating income	9.2	10.2	25.4	25.9
Depreciation and Amortization
Consolidated depreciation and amortization	4.1	4.0	12.1	11.7
Capital Expenditures
Consolidated capital expenditures	3.2	2.0	9.4	5.1
Total Assets
Consolidated total assets	446.6		446.6		451.6
Corporate
Operating Income
Consolidated operating income	(37.1)	(19.6)	(79.1)	(53.1)
Depreciation and Amortization
Consolidated depreciation and amortization	1.2	1.3	3.7	3.9
Capital Expenditures
Consolidated capital expenditures	0.8	0.5	2.9	1.0
Total Assets
Consolidated total assets	191.0		191.0		159.0
Intersegment
Net Sales
Total net sales	(26.0)	(28.4)	(66.8)	(69.6)
Operating Income
Consolidated operating income	0.3	$ (0.3)	0.9	$ (1.7)
Total Assets
Consolidated total assets	$ (19.7)		$ (19.7)		$ (17.9)