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		6 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Jun. 30, 2022
Net Sales:
Total net sales	$ 579.1	$ 396.0	$ 1,102.0	$ 783.6
Operating Income (Loss):
Consolidated operating income (loss)	22.6	(31.5)	30.9	(50.6)
Depreciation and Amortization:
Consolidated depreciation and amortization	32.5	32.8	64.8	65.3
Capital Expenditures:
Consolidated capital expenditures	17.5	19.1	31.0	33.4
Total Assets:
Consolidated total assets	3,056.5		3,056.5		$ 2,932.3
Operating | Specialty Alloys Operations
Net Sales:
Total net sales	495.8	330.8	943.2	662.8
Operating Income (Loss):
Consolidated operating income (loss)	30.3	(20.3)	50.2	(26.2)
Depreciation and Amortization:
Consolidated depreciation and amortization	27.3	27.4	54.4	54.6
Capital Expenditures:
Consolidated capital expenditures	16.0	16.6	27.4	28.7
Total Assets:
Consolidated total assets	2,482.1		2,482.1		2,262.4
Operating | Performance Engineered Products
Net Sales:
Total net sales	106.7	85.7	200.0	160.3
Operating Income (Loss):
Consolidated operating income (loss)	9.3	3.0	15.6	3.6
Depreciation and Amortization:
Consolidated depreciation and amortization	3.8	4.0	7.7	7.9
Capital Expenditures:
Consolidated capital expenditures	1.2	2.0	3.1	3.2
Total Assets:
Consolidated total assets	444.9		444.9		418.9
Corporate
Operating Income (Loss):
Consolidated operating income (loss)	(16.4)	(14.5)	(33.5)	(28.6)
Depreciation and Amortization:
Consolidated depreciation and amortization	1.4	1.4	2.7	2.8
Capital Expenditures:
Consolidated capital expenditures	0.3	0.5	0.5	1.5
Total Assets:
Consolidated total assets	136.0		136.0		248.9
Intersegment
Net Sales:
Total net sales	(23.4)	(20.5)	(41.2)	(39.5)
Operating Income (Loss):
Consolidated operating income (loss)	(0.6)	$ 0.3	(1.4)	$ 0.6
Total Assets:
Consolidated total assets	$ (6.5)		$ (6.5)		$ 2.1