Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2018	Jul. 31, 2017
Income Statement [Abstract]
Revenues	$ 1,624.3	$ 1,318.4	$ 4,793.5	$ 3,955.6
Operating expenses	1,446.7	1,184.5	4,281.8	3,544.1
Selling, general and administrative expenses	110.0	101.3	326.8	299.2
Restructuring and related expenses	2.9	5.2	22.5	16.0
Amortization of intangible assets	16.6	6.1	49.5	17.4
Impairment recovery and gain on sale	0.0	(1.1)	0.0	(18.5)
Operating profit	48.1	22.6	112.9	97.4
Income from unconsolidated affiliates, net	1.0	1.2	2.5	3.6
Interest expense	(12.9)	(2.8)	(41.0)	(9.1)
Income from continuing operations before income taxes	36.1	21.0	74.4	91.9
Income tax (provision) benefit	(2.4)	11.9	12.7	(11.3)
Income from continuing operations	33.7	32.9	87.1	80.6
(Loss) income from discontinued operations, net of taxes	(0.1)	0.0	1.0	(73.2)
Net income	33.6	32.9	88.1	7.4
Other comprehensive income (loss)
Interest rate swaps	(1.2)	(0.3)	22.0	2.3
Foreign currency translation	(6.5)	3.6	(1.5)	9.8
Income tax benefit (provision)	0.3	0.1	(5.9)	(0.9)
Comprehensive income	$ 26.2	$ 36.3	$ 102.6	$ 18.6
Net income per common share — Basic
Income from continuing operations (in usd per share)	$ 0.51	$ 0.59	$ 1.32	$ 1.44
Loss from discontinued operations (in usd per share)	0.00	0.00	0.02	(1.31)
Net income (loss) (in usd per share)	0.51	0.59	1.33	0.13
Net income per common share — Diluted
Income from continuing operations (in usd per share)	0.51	0.58	1.31	1.42
Loss from discontinued operations (in usd per share)	0.00	0.00	0.02	(1.29)
Net income (loss) (in usd per share)	$ 0.51	$ 0.58	$ 1.33	$ 0.13
Weighted-average common and common equivalent shares outstanding
Basic (in shares)	66.1	56.1	66.0	56.0
Diluted (in shares)	66.3	56.6	66.3	56.6
Dividends declared per common share (in usd per share)	$ 0.175	$ 0.17	$ 0.525	$ 0.51