Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
Revenue from External Customer [Line Items]
Revenues	$ 1,647.9	$ 1,624.3	$ 4,850.6	$ 4,793.5
Operating Segments
Revenue from External Customer [Line Items]
Revenues	1,679.3		4,948.9
Operating Segments | Business & Industry
Revenue from External Customer [Line Items]
Revenues	807.9	822.6	2,444.5	2,446.0
Operating Segments | Aviation
Revenue from External Customer [Line Items]
Revenues	263.3	260.5	765.8	769.7
Operating Segments | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	226.9	231.0	687.3	691.0
Operating Segments | Education
Revenue from External Customer [Line Items]
Revenues	215.4	215.9	633.6	637.8
Operating Segments | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	165.7	130.3	417.7	360.3
Operating Segments | Janitorial
Revenue from External Customer [Line Items]
Revenues	985.0		2,953.4
Operating Segments | Janitorial | Business & Industry
Revenue from External Customer [Line Items]
Revenues	576.9		1,738.2
Operating Segments | Janitorial | Aviation
Revenue from External Customer [Line Items]
Revenues	32.4		94.0
Operating Segments | Janitorial | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	184.2		554.4
Operating Segments | Janitorial | Education
Revenue from External Customer [Line Items]
Revenues	191.4		566.8
Operating Segments | Janitorial | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Parking
Revenue from External Customer [Line Items]
Revenues	220.1		658.8
Operating Segments | Parking | Business & Industry
Revenue from External Customer [Line Items]
Revenues	129.5		383.3
Operating Segments | Parking | Aviation
Revenue from External Customer [Line Items]
Revenues	83.6		253.7
Operating Segments | Parking | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	6.3		19.6
Operating Segments | Parking | Education
Revenue from External Customer [Line Items]
Revenues	0.7		2.3
Operating Segments | Parking | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Facility Services
Revenue from External Customer [Line Items]
Revenues	179.6		554.7
Operating Segments | Facility Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues	101.4		322.5
Operating Segments | Facility Services | Aviation
Revenue from External Customer [Line Items]
Revenues	18.5		54.5
Operating Segments | Facility Services | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	36.5		113.2
Operating Segments | Facility Services | Education
Revenue from External Customer [Line Items]
Revenues	23.3		64.6
Operating Segments | Facility Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0		0.0
Operating Segments | Building & Energy Solutions
Revenue from External Customer [Line Items]
Revenues	165.7		417.7
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	165.7		417.7
Operating Segments | Airline Services
Revenue from External Customer [Line Items]
Revenues	128.9		364.2
Operating Segments | Airline Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues	0.1		0.5
Operating Segments | Airline Services | Aviation
Revenue from External Customer [Line Items]
Revenues	128.8		363.7
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
Intersegment Eliminations
Revenue from External Customer [Line Items]
Revenues	$ (31.3)	$ (36.0)	$ (98.3)	$ (111.4)