REVENUES - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2023	Jul. 31, 2022
Revenue from External Customer [Line Items]
Revenues	$ 2,028.2	$ 1,961.4	$ 6,003.5	$ 5,795.5
B&I
Revenue from External Customer [Line Items]
Revenues	1,021.4	1,033.8	3,056.4	3,067.0
M&D
Revenue from External Customer [Line Items]
Revenues	381.9	358.1	1,135.5	1,074.1
Education
Revenue from External Customer [Line Items]
Revenues	219.1	207.5	650.7	617.6
Aviation
Revenue from External Customer [Line Items]
Revenues	238.0	203.5	677.5	589.7
Technical Solutions
Revenue from External Customer [Line Items]
Revenues	167.9	158.4	483.4	447.2
Janitorial
Revenue from External Customer [Line Items]
Revenues	1,277.8	1,213.1	3,740.0	3,591.5
Janitorial | B&I
Revenue from External Customer [Line Items]
Revenues	687.5	696.2	2,047.8	2,050.7
Janitorial | M&D
Revenue from External Customer [Line Items]
Revenues	334.8	311.0	988.6	922.3
Janitorial | Education
Revenue from External Customer [Line Items]
Revenues	218.6	178.4	594.5	534.7
Janitorial | Aviation
Revenue from External Customer [Line Items]
Revenues	36.9	27.5	109.0	83.8
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	196.9	182.0	582.3	525.2
Parking | B&I
Revenue from External Customer [Line Items]
Revenues	106.1	91.1	303.3	259.5
Parking | M&D
Revenue from External Customer [Line Items]
Revenues	9.9	8.4	31.3	27.9
Parking | Education
Revenue from External Customer [Line Items]
Revenues	0.2	0.1	0.7	0.6
Parking | Aviation
Revenue from External Customer [Line Items]
Revenues	80.6	82.4	247.1	237.2
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	272.6	321.3	900.6	983.2
Facility Services | B&I
Revenue from External Customer [Line Items]
Revenues	227.7	246.6	705.3	756.7
Facility Services | M&D
Revenue from External Customer [Line Items]
Revenues	37.2	38.7	115.7	123.9
Facility Services | Education
Revenue from External Customer [Line Items]
Revenues	0.3	29.0	55.5	82.3
Facility Services | Aviation
Revenue from External Customer [Line Items]
Revenues	7.4	7.0	24.2	20.3
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	167.9	158.4	483.4	447.2
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	167.9	158.4	483.4	447.2
Airline Services
Revenue from External Customer [Line Items]
Revenues	113.0	86.6	297.2	248.4
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	113.0	86.6	297.2	248.4
Airline Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	$ 0.0	$ 0.0	$ 0.0	$ 0.0