Revenue - Summary of revenue by geography (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Consolidated net sales	$ 351.9	$ 585.4	$ 1,054.0	$ 1,743.8
United States
Disaggregation of Revenue [Line Items]
Consolidated net sales	224.6	367.7	657.5	1,123.6
Europe
Disaggregation of Revenue [Line Items]
Consolidated net sales	55.5	109.5	184.9	304.7
Asia Pacific
Disaggregation of Revenue [Line Items]
Consolidated net sales	45.6	62.6	132.4	183.7
Mexico
Disaggregation of Revenue [Line Items]
Consolidated net sales	11.0	17.8	34.8	55.3
Canada
Disaggregation of Revenue [Line Items]
Consolidated net sales	9.3	15.1	24.2	44.4
Other
Disaggregation of Revenue [Line Items]
Consolidated net sales	$ 5.9	$ 12.7	$ 20.2	$ 32.1