Revenue - Schedule of External Net Sales Disaggregated by Major Stream Type (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Net sales	$ 2,009.2	$ 2,584.6	$ 4,220.4	$ 4,744.6
USA
Disaggregation of Revenue [Line Items]
Net sales	1,169.4	1,605.3	2,526.9	2,912.5
EMEA
Disaggregation of Revenue [Line Items]
Net sales	409.6	457.9	869.9	941.6
Canada
Disaggregation of Revenue [Line Items]
Net sales	331.5	404.8	617.3	678.6
LATAM
Disaggregation of Revenue [Line Items]
Net sales	98.7	116.6	206.3	211.9
Chemical Distribution
Disaggregation of Revenue [Line Items]
Net sales	1,775.2	2,312.8	3,819.2	4,348.0
Chemical Distribution | USA
Disaggregation of Revenue [Line Items]
Net sales	1,097.1	1,515.6	2,367.6	2,763.1
Chemical Distribution | EMEA
Disaggregation of Revenue [Line Items]
Net sales	409.3	457.5	869.2	940.9
Chemical Distribution | Canada
Disaggregation of Revenue [Line Items]
Net sales	172.0	225.1	380.3	436.8
Chemical Distribution | LATAM
Disaggregation of Revenue [Line Items]
Net sales	96.8	114.6	202.1	207.2
Crop Sciences
Disaggregation of Revenue [Line Items]
Net sales	147.4	167.1	211.8	217.6
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	147.4	167.1	211.8	217.6
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	86.6	104.7	189.4	179.0
Services | USA
Disaggregation of Revenue [Line Items]
Net sales	72.3	89.7	159.3	149.4
Services | EMEA
Disaggregation of Revenue [Line Items]
Net sales	0.3	0.4	0.7	0.7
Services | Canada
Disaggregation of Revenue [Line Items]
Net sales	12.1	12.6	25.2	24.2
Services | LATAM
Disaggregation of Revenue [Line Items]
Net sales	$ 1.9	$ 2.0	$ 4.2	$ 4.7