Revenue - Schedule of External Net Sales Disaggregated by Major Stream Type (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 2,009.2	$ 2,387.3	$ 6,229.6	$ 7,131.9
USA
Disaggregation of Revenue [Line Items]
Net sales	1,254.4	1,562.1	3,781.3	4,474.6
EMEA
Disaggregation of Revenue [Line Items]
Net sales	399.4	425.0	1,269.3	1,366.6
Canada
Disaggregation of Revenue [Line Items]
Net sales	234.9	283.0	852.2	961.6
LATAM
Disaggregation of Revenue [Line Items]
Net sales	120.5	117.2	326.8	329.1
Chemical Distribution
Disaggregation of Revenue [Line Items]
Net sales	1,875.7	2,223.0	5,694.9	6,571.0
Chemical Distribution | USA
Disaggregation of Revenue [Line Items]
Net sales	1,179.0	1,477.0	3,546.6	4,240.1
Chemical Distribution | EMEA
Disaggregation of Revenue [Line Items]
Net sales	399.1	424.7	1,268.3	1,365.6
Chemical Distribution | Canada
Disaggregation of Revenue [Line Items]
Net sales	179.8	207.3	560.1	644.1
Chemical Distribution | LATAM
Disaggregation of Revenue [Line Items]
Net sales	117.8	114.0	319.9	321.2
Crop Sciences
Disaggregation of Revenue [Line Items]
Net sales	43.9	64.3	255.7	281.9
Crop Sciences | USA
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Crop Sciences | EMEA
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Crop Sciences | Canada
Disaggregation of Revenue [Line Items]
Net sales	43.9	64.3	255.7	281.9
Crop Sciences | LATAM
Disaggregation of Revenue [Line Items]
Net sales	0.0	0.0	0.0	0.0
Services
Disaggregation of Revenue [Line Items]
Net sales	89.6	100.0	279.0	279.0
Services | USA
Disaggregation of Revenue [Line Items]
Net sales	75.4	85.1	234.7	234.5
Services | EMEA
Disaggregation of Revenue [Line Items]
Net sales	0.3	0.3	1.0	1.0
Services | Canada
Disaggregation of Revenue [Line Items]
Net sales	11.2	11.4	36.4	35.6
Services | LATAM
Disaggregation of Revenue [Line Items]
Net sales	$ 2.7	$ 3.2	$ 6.9	$ 7.9