Revenue - Disaggregation of Sales - Schedule of Disaggregates of Net Sales of our Chemicals Segment (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation Of Revenue [Line Items]
Net sales	$ 492.7	$ 629.0
Chemicals
Disaggregation Of Revenue [Line Items]
Net sales	426.3	562.9
Point of Origin | Chemicals
Disaggregation Of Revenue [Line Items]
Net sales	426.3	562.9
Point of Origin | Chemicals | United States
Disaggregation Of Revenue [Line Items]
Net sales	255.8	326.4
Point of Origin | Chemicals | Germany
Disaggregation Of Revenue [Line Items]
Net sales	186.0	276.5
Point of Origin | Chemicals | Canada
Disaggregation Of Revenue [Line Items]
Net sales	90.9	96.4
Point of Origin | Chemicals | Belgium
Disaggregation Of Revenue [Line Items]
Net sales	68.8	92.8
Point of Origin | Chemicals | Norway
Disaggregation Of Revenue [Line Items]
Net sales	71.9	78.4
Point of Origin | Chemicals | Eliminations
Disaggregation Of Revenue [Line Items]
Net sales	(247.1)	(307.6)
Point of Destination | Chemicals
Disaggregation Of Revenue [Line Items]
Net sales	426.3	562.9
Point of Destination | Chemicals | Europe
Disaggregation Of Revenue [Line Items]
Net sales	201.1	269.5
Point of Destination | Chemicals | North America
Disaggregation Of Revenue [Line Items]
Net sales	148.6	179.9
Point of Destination | Chemicals | Other
Disaggregation Of Revenue [Line Items]
Net sales	$ 76.6	$ 113.5