Geographic information - Net Sales and Property and Equipment by Geographical Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	$ 1,666.5	$ 1,930.2	$ 1,939.4
Net property and equipment	482.9	484.5
Germany
Revenues From External Customers And Long Lived Assets [Line Items]
Net property and equipment	207.7	198.5
Canada
Revenues From External Customers And Long Lived Assets [Line Items]
Net property and equipment	81.9	87.8
Norway
Revenues From External Customers And Long Lived Assets [Line Items]
Net property and equipment	82.7	82.7
Belgium
Revenues From External Customers And Long Lived Assets [Line Items]
Net property and equipment	97.9	100.8
Other
Revenues From External Customers And Long Lived Assets [Line Items]
Net property and equipment	12.7	14.7
Point of origin | Reportable geographical components | United States
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	1,029.2	1,226.6	1,052.1
Point of origin | Reportable geographical components | Germany
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	726.4	895.4	971.7
Point of origin | Reportable geographical components | Canada
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	351.0	389.4	371.9
Point of origin | Reportable geographical components | Norway
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	252.1	273.5	257.2
Point of origin | Reportable geographical components | Belgium
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	217.1	306.5	295.7
Point of origin | Eliminations
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	(909.3)	(1,161.2)	(1,009.2)
Point of destination | Europe
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	737.8	878.3	945.0
Point of destination | North America
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	618.1	695.7	645.7
Point of destination | Other
Revenues From External Customers And Long Lived Assets [Line Items]
Net sales	$ 310.6	$ 356.2	$ 348.7