Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2020	Jul. 31, 2019
Revenue from External Customer [Line Items]
Revenues	$ 1,394.1	$ 1,647.9	$ 4,503.0	$ 4,850.6
Operating Segments
Revenue from External Customer [Line Items]
Revenues	1,424.2	1,679.3	4,594.1	4,948.9
Operating Segments | Business & Industry
Revenue from External Customer [Line Items]
Revenues	756.9	807.9	2,363.4	2,444.5
Operating Segments | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	243.2	226.9	710.8	687.3
Operating Segments | Education
Revenue from External Customer [Line Items]
Revenues	188.6	215.4	596.6	633.6
Operating Segments | Aviation
Revenue from External Customer [Line Items]
Revenues	116.4	263.3	539.9	765.8
Operating Segments | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	119.2	165.7	383.5	417.7
Operating Segments | Janitorial
Revenue from External Customer [Line Items]
Revenues	986.6	985.0	2,980.5	2,953.4
Operating Segments | Janitorial | Business & Industry
Revenue from External Customer [Line Items]
Revenues	596.9	576.9	1,786.9	1,738.2
Operating Segments | Janitorial | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	197.1	184.2	573.1	554.4
Operating Segments | Janitorial | Education
Revenue from External Customer [Line Items]
Revenues	165.7	191.4	529.4	566.8
Operating Segments | Janitorial | Aviation
Revenue from External Customer [Line Items]
Revenues	26.9	32.4	91.2	94.0
Operating Segments | Janitorial | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Operating Segments | Parking
Revenue from External Customer [Line Items]
Revenues	123.3	220.1	519.4	658.8
Operating Segments | Parking | Business & Industry
Revenue from External Customer [Line Items]
Revenues	67.7	129.5	290.7	383.3
Operating Segments | Parking | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	8.5	6.3	24.0	19.6
Operating Segments | Parking | Education
Revenue from External Customer [Line Items]
Revenues	0.2	0.7	1.5	2.3
Operating Segments | Parking | Aviation
Revenue from External Customer [Line Items]
Revenues	46.9	83.6	203.1	253.7
Operating Segments | Parking | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Operating Segments | Facility Services
Revenue from External Customer [Line Items]
Revenues	158.8	179.6	489.7	554.7
Operating Segments | Facility Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues	92.2	101.4	285.5	322.5
Operating Segments | Facility Services | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	37.6	36.5	113.7	113.2
Operating Segments | Facility Services | Education
Revenue from External Customer [Line Items]
Revenues	22.7	23.3	65.7	64.6
Operating Segments | Facility Services | Aviation
Revenue from External Customer [Line Items]
Revenues	6.3	18.5	24.8	54.5
Operating Segments | Facility Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Operating Segments | Building & Energy Solutions
Revenue from External Customer [Line Items]
Revenues	119.2	165.7	383.5	417.7
Operating Segments | Building & Energy Solutions | Business & Industry
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Operating Segments | Building & Energy Solutions | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Operating Segments | Building & Energy Solutions | Education
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Operating Segments | Building & Energy Solutions | Aviation
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Operating Segments | Building & Energy Solutions | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	119.2	165.7	383.5	417.7
Operating Segments | Airline Services
Revenue from External Customer [Line Items]
Revenues	36.3	128.9	221.0	364.2
Operating Segments | Airline Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues	0.1	0.1	0.3	0.5
Operating Segments | Airline Services | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.1
Operating Segments | Airline Services | Education
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Operating Segments | Airline Services | Aviation
Revenue from External Customer [Line Items]
Revenues	36.2	128.8	220.7	363.7
Operating Segments | Airline Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Intersegment Eliminations
Revenue from External Customer [Line Items]
Revenues	$ (30.1)	$ (31.3)	$ (91.1)	$ (98.3)