Commitments and Contingencies - Environmental Matter (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Oct. 31, 2020	Jan. 31, 2020	Oct. 31, 2016
Site Contingency [Line Items]
Estimated remediation costs, CPG preferred approach, low estimate		$ 483.0
Identified remediation plan, EPA estimated cost	$ 1,380.0
Remediation term	6 years
RoD design phase, settlement amount from third party			$ 165.0
Minimum
Site Contingency [Line Items]
Design term	3 years
Maximum
Site Contingency [Line Items]
Design term	4 years