Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Income Statement [Abstract]
Revenues	$ 1,594.7	$ 1,580.8	$ 3,202.6	$ 3,169.2
Operating expenses	1,414.2	1,405.8	2,860.2	2,835.1
Selling, general and administrative expenses	108.4	107.8	221.1	216.8
Restructuring and related expenses	2.7	5.3	6.5	19.6
Amortization of intangible assets	14.8	16.7	30.0	32.9
Operating profit	54.5	45.3	84.8	64.8
Income from unconsolidated affiliates	0.8	1.0	1.7	1.6
Interest expense	(12.8)	(13.8)	(26.3)	(28.1)
Income from continuing operations before income taxes	42.5	32.5	60.2	38.2
Income tax (provision) benefit	(12.6)	(7.1)	(17.3)	15.1
Income from continuing operations	29.9	25.4	42.9	53.3
(Loss) income from discontinued operations, net of taxes	(0.2)	1.2	(0.2)	1.1
Net income	29.7	26.6	42.7	54.4
Other comprehensive income (loss)
Interest rate swaps	(3.5)	4.6	(12.2)	23.2
Foreign currency translation	(0.9)	(4.5)	2.2	5.0
Income tax benefit (provision)	1.0	(1.2)	3.3	(6.3)
Comprehensive income	$ 26.3	$ 25.5	$ 36.0	$ 76.3
Net income per common share — Basic
Income from continuing operations (in usd per share)	$ 0.45	$ 0.38	$ 0.65	$ 0.81
Income from discontinued operations (in usd per share)	0.00	0.02	0.00	0.02
Net income (in usd per share)	0.45	0.40	0.64	0.83
Net income per common share — Diluted
Income from continuing operations (in usd per share)	0.45	0.38	0.64	0.80
Income from discontinued operations (in usd per share)	0.00	0.02	0.00	0.02
Net income (in usd per share)	$ 0.45	$ 0.40	$ 0.64	$ 0.82
Weighted-average common and common equivalent shares outstanding
Basic (in shares)	66.5	66.0	66.4	66.0
Diluted (in shares)	66.8	66.2	66.7	66.3