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, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022	Jun. 30, 2022
Net Sales
Total net sales	$ 690.1	$ 489.0	$ 1,792.1	$ 1,272.6
Operating Income (Loss)
Consolidated operating income (loss)	39.3	1.1	70.2	(49.5)
Depreciation and Amortization
Consolidated depreciation and amortization	32.8	33.2	97.5	98.5
Capital Expenditures
Consolidated capital expenditures	20.5	25.1	51.5	58.5
Total Assets
Consolidated total assets	3,094.3		3,094.3		$ 2,932.3
Specialty Alloys Operations
Net Sales
Total net sales	603.4	418.0	1,546.6	1,080.7
Performance Engineered Products
Net Sales
Total net sales	115.1	88.4	315.1	248.7
Operating | Specialty Alloys Operations
Net Sales
Total net sales	603.4	418.0	1,546.6	1,080.7
Operating Income (Loss)
Consolidated operating income (loss)	49.0	5.8	99.1	(20.4)
Depreciation and Amortization
Consolidated depreciation and amortization	27.5	27.9	81.9	82.4
Capital Expenditures
Consolidated capital expenditures	18.0	21.8	45.4	50.5
Total Assets
Consolidated total assets	2,506.3		2,506.3		2,262.4
Operating | Performance Engineered Products
Net Sales
Total net sales	115.1	88.4	315.1	248.7
Operating Income (Loss)
Consolidated operating income (loss)	10.2	4.2	25.9	7.8
Depreciation and Amortization
Consolidated depreciation and amortization	4.0	3.9	11.7	11.8
Capital Expenditures
Consolidated capital expenditures	2.0	2.8	5.1	6.0
Total Assets
Consolidated total assets	457.9		457.9		418.9
Corporate
Operating Income (Loss)
Consolidated operating income (loss)	(19.6)	(8.6)	(53.1)	(37.3)
Depreciation and Amortization
Consolidated depreciation and amortization	1.3	1.4	4.0	4.3
Capital Expenditures
Consolidated capital expenditures	0.5	0.5	1.0	2.0
Total Assets
Consolidated total assets	139.2		139.2		248.9
Intersegment
Net Sales
Total net sales	(28.4)	(17.4)	(69.6)	(56.8)
Operating Income (Loss)
Consolidated operating income (loss)	(0.3)	$ (0.3)	(1.7)	$ 0.4
Total Assets
Consolidated total assets	$ (9.1)		$ (9.1)		$ 2.1