Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019
Operating loss carryforwards disclosures
Deferred income taxes	$ (33.6)	$ (0.4)	$ 16.5
Deferred tax assets, operating loss carryforwards, subject to expiration	388.8
Amount of future tax benefits	11.0
Increase (decrease) in valuation allowance	1.0
Operating loss carryforward, income tax benefit	0.0
Unrecognized tax benefits	0.0	$ 0.0	$ 0.0
Undistributed earnings of foreign subsidiaries	56.4
Unrecognized tax expense, due to undistributed earnings of foreign subsidiaries not being repatriated	0.8
United Kingdom
Operating loss carryforwards disclosures
Deferred tax assets, operating loss carryforwards, not subject to expiration	8.2
Deferred income taxes	3.9
Increase (decrease) in valuation allowance	1.0
Singapore
Operating loss carryforwards disclosures
Deferred tax assets, operating loss carryforwards, not subject to expiration	1.7
Deferred income taxes	0.0
Sweden
Operating loss carryforwards disclosures
Deferred tax assets, operating loss carryforwards, not subject to expiration	0.7
Deferred income taxes	0.0
Operating Loss Carryforward, Expired
Operating loss carryforwards disclosures
Increase (decrease) in valuation allowance	(2.6)
Operating Losses, Jurisdictions Without Tax Benefits
Operating loss carryforwards disclosures
Increase (decrease) in valuation allowance	$ 2.6