Segment information - Reconciliation of Segment Operating Income to Consolidated Income Before Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	$ 572.0	$ 483.0	$ 534.0
Selling, general and administrative expense	(389.5)	(369.4)	(364.8)
Research and development expense	(28.5)	(26.6)	(31.3)
Interest expense	(35.4)	(29.2)	(62.1)
Other (expense), net	(580.3)	(329.6)	(136.4)
Total loss from continuing operations before income taxes	(461.7)	(271.8)	(60.6)
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	561.5	454.2	512.9
Other gross profit
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gross profit	10.5	28.8	21.1
Interest expense	(35.4)	(29.2)	(62.1)
Other (expense), net	$ (580.3)	$ (329.6)	$ (136.4)