Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Income Statement [Abstract]
Revenues	$ 1,647.9	$ 1,624.3	$ 4,850.6	$ 4,793.5
Operating expenses	1,454.1	1,446.7	4,314.2	4,281.8
Selling, general and administrative expenses	119.8	110.0	340.9	326.8
Restructuring and related expenses	2.0	2.9	8.5	22.5
Amortization of intangible assets	14.9	16.6	44.9	49.5
Operating profit	57.3	48.1	142.1	112.9
Income from unconsolidated affiliates	0.7	1.0	2.4	2.5
Interest expense	(12.9)	(12.9)	(39.2)	(41.0)
Income from continuing operations before income taxes	45.0	36.1	105.3	74.4
Income tax (provision) benefit	(8.5)	(2.4)	(25.8)	12.7
Income from continuing operations	36.5	33.7	79.4	87.1
Income (loss) from discontinued operations, net of taxes	0.2	(0.1)	0.0	1.0
Net income	36.8	33.6	79.4	88.1
Other comprehensive income (loss)
Interest rate swaps	(5.7)	(1.2)	(17.9)	22.0
Foreign currency translation	(4.6)	(6.5)	(2.4)	(1.5)
Income tax benefit (provision)	1.6	0.3	4.9	(5.9)
Comprehensive income	$ 28.0	$ 26.2	$ 64.0	$ 102.6
Net income per common share — Basic
Income from continuing operations (in usd per share)	$ 0.55	$ 0.51	$ 1.19	$ 1.32
Income from discontinued operations (in usd per share)	0	0	0	0.02
Net income (in usd per share)	0.55	0.51	1.19	1.33
Net income per common share — Diluted
Income from continuing operations (in usd per share)	0.55	0.51	1.19	1.31
Income from discontinued operations (in usd per share)	0	0	0	0.02
Net income (in usd per share)	$ 0.55	$ 0.51	$ 1.19	$ 1.33
Weighted-average common and common equivalent shares outstanding
Basic (in shares)	66.6	66.1	66.5	66.0
Diluted (in shares)	67.0	66.3	66.8	66.3