Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2019	Apr. 30, 2018	Apr. 30, 2019	Apr. 30, 2018
Revenue from External Customer [Line Items]
Revenues	$ 1,594.7	$ 1,580.8	$ 3,202.6	$ 3,169.2
Operating Segments
Revenue from External Customer [Line Items]
Revenues	1,627.3		3,269.6
Operating Segments | Business & Industry
Revenue from External Customer [Line Items]
Revenues	753.4	755.1	1,527.9	1,511.3
Operating Segments | Aviation
Revenue from External Customer [Line Items]
Revenues	250.0	249.2	502.4	509.2
Operating Segments | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	224.3	227.8	460.4	460.0
Operating Segments | Education
Revenue from External Customer [Line Items]
Revenues	205.6	206.9	410.3	413.8
Operating Segments | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	127.6	108.5	235.5	212.5
Operating Segments | Healthcare
Revenue from External Customer [Line Items]
Revenues	66.3	69.9	133.0	137.6
Operating Segments | Janitorial
Revenue from External Customer [Line Items]
Revenues	978.5		1,968.4
Operating Segments | Janitorial | Business & Industry
Revenue from External Customer [Line Items]
Revenues	542.8		1,092.5
Operating Segments | Janitorial | Aviation
Revenue from External Customer [Line Items]
Revenues	30.4		61.5
Operating Segments | Janitorial | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	184.4		372.2
Operating Segments | Janitorial | Education
Revenue from External Customer [Line Items]
Revenues	184.2		367.5
Operating Segments | Janitorial | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Janitorial | Healthcare
Revenue from External Customer [Line Items]
Revenues	36.6		74.6
Operating Segments | Parking
Revenue from External Customer [Line Items]
Revenues	216.7		438.8
Operating Segments | Parking | Business & Industry
Revenue from External Customer [Line Items]
Revenues	111.2		225.5
Operating Segments | Parking | Aviation
Revenue from External Customer [Line Items]
Revenues	84.2		170.0
Operating Segments | Parking | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	5.9		13.3
Operating Segments | Parking | Education
Revenue from External Customer [Line Items]
Revenues	0.8		1.6
Operating Segments | Parking | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Parking | Healthcare
Revenue from External Customer [Line Items]
Revenues	14.6		28.3
Operating Segments | Facility Services
Revenue from External Customer [Line Items]
Revenues	186.9		391.6
Operating Segments | Facility Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues	99.3		209.5
Operating Segments | Facility Services | Aviation
Revenue from External Customer [Line Items]
Revenues	17.9		35.9
Operating Segments | Facility Services | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	34.0		74.8
Operating Segments | Facility Services | Education
Revenue from External Customer [Line Items]
Revenues	20.6		41.3
Operating Segments | Facility Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Facility Services | Healthcare
Revenue from External Customer [Line Items]
Revenues	15.1		30.1
Operating Segments | Building & Energy Solutions
Revenue from External Customer [Line Items]
Revenues	127.6		235.5
Operating Segments | Building & Energy Solutions | Business & Industry
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Building & Energy Solutions | Aviation
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Building & Energy Solutions | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Building & Energy Solutions | Education
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Building & Energy Solutions | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	127.6		235.5
Operating Segments | Building & Energy Solutions | Healthcare
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Airline Services
Revenue from External Customer [Line Items]
Revenues	117.6		235.3
Operating Segments | Airline Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues	0.2		0.4
Operating Segments | Airline Services | Aviation
Revenue from External Customer [Line Items]
Revenues	117.4		234.9
Operating Segments | Airline Services | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	0.0		0.1
Operating Segments | Airline Services | Education
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Airline Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Airline Services | Healthcare
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Intersegment Eliminations
Revenue from External Customer [Line Items]
Revenues	$ (32.6)	$ (36.5)	$ (67.0)	$ (75.4)