Income taxes - Net Deferred Tax Asset (Liability) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets
Federal losses carryforward	$ 15.3	$ 7.6
State losses carryforward	5.4	3.3
R&D carryforward	18.4	16.6
Stock compensation	10.1	8.9
Foreign losses carryforward	9.1	10.2
Deferred revenue	2.0	0.4
Inventory reserves	10.5	2.9
Lease liability	4.6	6.5
IRC 263A capitalized costs	5.0	3.9
Capitalized R&D	25.9	0.0
Deferred Tax Asset, Interest Carryforward	7.6	0.0
Other	0.7	5.6
Gross deferred tax assets	114.6	65.9
Valuation allowance	(68.0)	(25.0)
Total deferred tax assets	46.6	40.9
Deferred tax liabilities
Fixed assets	(62.4)	(75.1)
Intangible assets	(46.1)	(47.6)
Right-of-use asset	(4.3)	(6.1)
Foreign Withholding Tax	(4.7)	0.0
Other	(0.9)	(2.8)
Total deferred tax liabilities	(118.4)	(131.6)
Net deferred tax liabilities	$ (71.8)	$ (90.7)