REVENUES - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2023	Apr. 30, 2022
Revenue from External Customer [Line Items]
Revenues	$ 1,984.0	$ 1,897.8	$ 3,975.3	$ 3,834.1
B&I
Revenue from External Customer [Line Items]
Revenues	998.5	1,003.6	2,035.0	2,033.1
M&D
Revenue from External Customer [Line Items]
Revenues	373.2	356.9	753.7	716.0
Education
Revenue from External Customer [Line Items]
Revenues	216.7	204.4	431.6	410.1
Aviation
Revenue from External Customer [Line Items]
Revenues	227.2	185.9	439.5	386.1
Technical Solutions
Revenue from External Customer [Line Items]
Revenues	168.4	147.0	315.5	288.8
Janitorial
Revenue from External Customer [Line Items]
Revenues	1,223.2	1,188.2	2,462.4	2,378.4
Janitorial | B&I
Revenue from External Customer [Line Items]
Revenues	673.5	676.7	1,360.6	1,354.6
Janitorial | M&D
Revenue from External Customer [Line Items]
Revenues	325.3	307.2	653.8	611.3
Janitorial | Education
Revenue from External Customer [Line Items]
Revenues	188.2	177.9	375.9	356.2
Janitorial | Aviation
Revenue from External Customer [Line Items]
Revenues	36.2	26.4	72.1	56.2
Janitorial | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Parking
Revenue from External Customer [Line Items]
Revenues	202.1	171.2	385.5	343.2
Parking | B&I
Revenue from External Customer [Line Items]
Revenues	100.3	85.1	197.1	168.4
Parking | M&D
Revenue from External Customer [Line Items]
Revenues	9.9	8.8	21.3	19.5
Parking | Education
Revenue from External Customer [Line Items]
Revenues	0.3	0.3	0.5	0.5
Parking | Aviation
Revenue from External Customer [Line Items]
Revenues	91.7	77.1	166.5	154.8
Parking | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Facility Services
Revenue from External Customer [Line Items]
Revenues	298.9	315.8	627.8	661.9
Facility Services | B&I
Revenue from External Customer [Line Items]
Revenues	224.7	241.8	477.3	510.2
Facility Services | M&D
Revenue from External Customer [Line Items]
Revenues	38.0	41.0	78.5	85.2
Facility Services | Education
Revenue from External Customer [Line Items]
Revenues	28.2	26.3	55.2	53.3
Facility Services | Aviation
Revenue from External Customer [Line Items]
Revenues	8.0	6.8	16.8	13.3
Facility Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Building & Energy Solutions
Revenue from External Customer [Line Items]
Revenues	168.4	147.0	315.5	288.8
Building & Energy Solutions | B&I
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Building & Energy Solutions | M&D
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Building & Energy Solutions | Education
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Building & Energy Solutions | Aviation
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Building & Energy Solutions | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	168.4	147.0	315.5	288.8
Airline Services
Revenue from External Customer [Line Items]
Revenues	91.3	75.5	184.1	161.8
Airline Services | B&I
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Airline Services | M&D
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Airline Services | Education
Revenue from External Customer [Line Items]
Revenues	0.0	0.0	0.0	0.0
Airline Services | Aviation
Revenue from External Customer [Line Items]
Revenues	91.3	75.5	184.1	161.8
Airline Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	$ 0.0	$ 0.0	$ 0.0	$ 0.0