Restructuring and Related Costs - Cumulative Restructuring and Related Charges (Details) $ in Millions	Oct. 31, 2018 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	$ 89.9
GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	23.3
2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	66.5
External Support Fees
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	32.0
External Support Fees | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	2.0
External Support Fees | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	30.0
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	26.5
Employee Severance | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	13.5
Employee Severance | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	13.0
Other Project Fees
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	18.5
Other Project Fees | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	7.9
Other Project Fees | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	10.7
Lease Exit
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	7.7
Lease Exit | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	0.0
Lease Exit | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	7.7
Asset Impairment
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	5.2
Asset Impairment | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	0.0
Asset Impairment | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	$ 5.2