Revenues - Contract with Customer, Asset and Liability (Details) - USD ($)	3 Months Ended
	Jan. 31, 2020	Oct. 31, 2019
Revenue from Contract with Customer [Abstract]
Billed trade receivables	$ 962,500,000	$ 978,700,000
Unbilled trade receivables	63,400,000	56,900,000
Costs incurred in excess of amounts billed	79,600,000	72,600,000
Capitalized commissions	21,600,000	$ 21,800,000
Capitalized contract price	3,500,000
Capitalized contract cost, amortization	(3,700,000)
Capitalized contract cost, impairment loss	0
Contract with Customer, Liabilities [Roll Forward]
Contract liabilities, balance at beginning of period	38,000,000.0
Additional contract liabilities	73,500,000
Recognition of deferred revenue	(74,600,000)
Contract liabilities, balance at end of period	$ 36,900,000