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
	Sep. 30, 2022	Sep. 30, 2021	Jun. 30, 2022
Net Sales:
Consolidated net sales	$ 522.9	$ 387.6
Operating Income (Loss):
Consolidated operating income (loss)	8.3	(19.1)
Depreciation and Amortization:
Consolidated depreciation and amortization	32.3	32.5
Capital Expenditures:
Consolidated capital expenditures	13.5	14.4
Total Assets:
Consolidated total assets	2,939.9		$ 2,932.3
Operating | Specialty Alloys Operations
Net Sales:
Consolidated net sales	447.3	331.9
Operating Income (Loss):
Consolidated operating income (loss)	19.9	(5.9)
Depreciation and Amortization:
Consolidated depreciation and amortization	27.1	27.2
Capital Expenditures:
Consolidated capital expenditures	11.4	12.1
Total Assets:
Consolidated total assets	2,339.3		2,262.4
Operating | Performance Engineered Products
Net Sales:
Consolidated net sales	93.2	74.6
Operating Income (Loss):
Consolidated operating income (loss)	6.3	0.6
Depreciation and Amortization:
Consolidated depreciation and amortization	3.8	3.9
Capital Expenditures:
Consolidated capital expenditures	2.0	1.3
Total Assets:
Consolidated total assets	433.2		418.9
Corporate
Operating Income (Loss):
Consolidated operating income (loss)	(17.1)	(14.2)
Depreciation and Amortization:
Consolidated depreciation and amortization	1.4	1.4
Capital Expenditures:
Consolidated capital expenditures	0.1	1.0
Total Assets:
Consolidated total assets	163.9		248.9
Intersegment
Net Sales:
Consolidated net sales	(17.6)	(18.9)
Operating Income (Loss):
Consolidated operating income (loss)	(0.8)	$ 0.4
Total Assets:
Consolidated total assets	$ 3.5		$ 2.1