Segment Information - Financial Information by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 1,318.4	$ 1,296.9	$ 3,955.6	$ 3,822.4
Operating profit (loss)	22.6	18.5	97.4	44.0
Adjustment for income from unconsolidated affiliates, net, included in Aviation and Government Services	1.2	2.1	3.6	5.3
Income from unconsolidated affiliates, net	1.2	2.1	3.6	5.3
Interest expense	(2.8)	(2.6)	(9.1)	(7.7)
Income from continuing operations before income taxes	21.0	18.0	91.9	41.6
Corporate
Segment Reporting Information [Line Items]
Operating profit (loss)	(47.5)	(55.0)	(118.5)	(130.5)
Segment Reconciling Items
Segment Reporting Information [Line Items]
Adjustment for income from unconsolidated affiliates, net, included in Aviation and Government Services	(1.0)	(1.3)	(3.4)	(4.6)
Adjustment for tax deductions for energy efficient government buildings, included in Technical Solutions	(0.4)	(0.1)	(1.8)	(1.2)
Income from unconsolidated affiliates, net	(1.0)	(1.3)	(3.4)	(4.6)
Business & Industry | Operating Segments
Segment Reporting Information [Line Items]
Revenues	749.9	733.4	2,237.5	2,207.4
Operating profit (loss)	42.2	40.7	115.6	101.8
Aviation | Operating Segments
Segment Reporting Information [Line Items]
Revenues	259.1	219.1	723.3	625.9
Operating profit (loss)	6.2	8.3	19.2	17.7
Emerging Industries Group | Operating Segments
Segment Reporting Information [Line Items]
Revenues	190.5	200.6	583.2	594.7
Operating profit (loss)	11.6	16.9	36.0	44.7
Technical Solutions | Operating Segments
Segment Reporting Information [Line Items]
Revenues	106.7	115.4	325.2	309.8
Operating profit (loss)	9.8	10.0	28.6	18.4
Government Services | Operating Segments
Segment Reporting Information [Line Items]
Revenues	12.3	28.3	86.5	84.6
Operating profit (loss)	$ 1.7	$ (1.0)	$ 21.8	$ (2.3)