Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2021	Jul. 31, 2020	Jul. 31, 2021	Jul. 31, 2020
Revenue from External Customer [Line Items]
Revenues	$ 1,543.1	$ 1,394.1	$ 4,533.0	$ 4,503.0
Operating Segments
Revenue from External Customer [Line Items]
Revenues	1,584.1	1,424.2	4,639.1	4,594.1
Operating Segments | Business & Industry
Revenue from External Customer [Line Items]
Revenues	807.7	756.9	2,413.3	2,363.4
Operating Segments | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	246.1	243.2	741.6	710.8
Operating Segments | Education
Revenue from External Customer [Line Items]
Revenues	208.4	188.6	632.0	596.6
Operating Segments | Aviation
Revenue from External Customer [Line Items]
Revenues	175.7	116.4	467.2	539.9
Operating Segments | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	146.1	119.2	385.0	383.5
Operating Segments | Janitorial
Revenue from External Customer [Line Items]
Revenues	1,058.3	986.6	3,173.8	2,980.5
Operating Segments | Janitorial | Business & Industry
Revenue from External Customer [Line Items]
Revenues	650.4	596.9	1,941.7	1,786.9
Operating Segments | Janitorial | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	197.6	197.1	591.8	573.1
Operating Segments | Janitorial | Education
Revenue from External Customer [Line Items]
Revenues	181.6	165.7	553.4	529.4
Operating Segments | Janitorial | Aviation
Revenue from External Customer [Line Items]
Revenues	28.7	26.9	86.9	91.2
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	152.8	123.3	429.5	519.4
Operating Segments | Parking | Business & Industry
Revenue from External Customer [Line Items]
Revenues	76.4	67.7	213.7	290.7
Operating Segments | Parking | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	9.2	8.5	30.9	24.0
Operating Segments | Parking | Education
Revenue from External Customer [Line Items]
Revenues	0.2	0.2	0.6	1.5
Operating Segments | Parking | Aviation
Revenue from External Customer [Line Items]
Revenues	66.9	46.9	184.2	203.1
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	154.2	158.8	475.7	489.7
Operating Segments | Facility Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues	80.8	92.2	257.5	285.5
Operating Segments | Facility Services | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	39.3	37.6	118.9	113.7
Operating Segments | Facility Services | Education
Revenue from External Customer [Line Items]
Revenues	26.7	22.7	78.1	65.7
Operating Segments | Facility Services | Aviation
Revenue from External Customer [Line Items]
Revenues	7.5	6.3	21.2	24.8
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	146.1	119.2	385.0	383.5
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	146.1	119.2	385.0	383.5
Operating Segments | Airline Services
Revenue from External Customer [Line Items]
Revenues	72.7	36.3	175.1	221.0
Operating Segments | Airline Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues	0.1	0.1	0.3	0.3
Operating Segments | Airline Services | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
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	72.6	36.2	174.8	220.7
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	$ (40.9)	$ (30.1)	$ (106.1)	$ (91.1)