REVENUES - Schedule of Disaggregation of Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2025	Oct. 31, 2024	Oct. 31, 2023
Revenue from External Customer [Line Items]
Revenues	$ 8,745.9	$ 8,359.4	$ 8,096.4
B&I
Revenue from External Customer [Line Items]
Revenues	4,126.0	4,059.1
M&D
Revenue from External Customer [Line Items]
Revenues	1,618.6	1,554.3
Aviation
Revenue from External Customer [Line Items]
Revenues	1,118.7	1,032.6
Education
Revenue from External Customer [Line Items]
Revenues	922.0	904.0
Technical Solutions
Revenue from External Customer [Line Items]
Revenues	960.6	809.3
Facility Solutions
Revenue from External Customer [Line Items]
Revenues	6,554.5	6,382.8
Facility Solutions | B&I
Revenue from External Customer [Line Items]
Revenues	3,279.7	3,200.2
Facility Solutions | M&D
Revenue from External Customer [Line Items]
Revenues	1,403.6	1,398.2
Facility Solutions | Aviation
Revenue from External Customer [Line Items]
Revenues	1,065.8	985.3
Facility Solutions | Education
Revenue from External Customer [Line Items]
Revenues	805.4	799.1
Facility Solutions | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Janitorial
Revenue from External Customer [Line Items]
Revenues	5,233.1	5,116.1
Janitorial | B&I
Revenue from External Customer [Line Items]
Revenues	2,849.4	2,781.4
Janitorial | M&D
Revenue from External Customer [Line Items]
Revenues	1,350.5	1,347.0
Janitorial | Aviation
Revenue from External Customer [Line Items]
Revenues	228.1	189.0
Janitorial | Education
Revenue from External Customer [Line Items]
Revenues	805.0	798.7
Janitorial | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Aviation Services
Revenue from External Customer [Line Items]
Revenues	502.6	461.8
Aviation Services | B&I
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Aviation Services | M&D
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Aviation Services | Aviation
Revenue from External Customer [Line Items]
Revenues	502.6	461.8
Aviation Services | Education
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Aviation Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Parking and Transportation
Revenue from External Customer [Line Items]
Revenues	818.8	804.9
Parking and Transportation | B&I
Revenue from External Customer [Line Items]
Revenues	430.3	418.9
Parking and Transportation | M&D
Revenue from External Customer [Line Items]
Revenues	53.1	51.2
Parking and Transportation | Aviation
Revenue from External Customer [Line Items]
Revenues	335.0	334.5
Parking and Transportation | Education
Revenue from External Customer [Line Items]
Revenues	0.4	0.4
Parking and Transportation | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Engineering and Infrastructure Solutions
Revenue from External Customer [Line Items]
Revenues	2,191.4	1,976.5
Engineering and Infrastructure Solutions | B&I
Revenue from External Customer [Line Items]
Revenues	846.3	858.9
Engineering and Infrastructure Solutions | M&D
Revenue from External Customer [Line Items]
Revenues	215.0	156.1
Engineering and Infrastructure Solutions | Aviation
Revenue from External Customer [Line Items]
Revenues	52.9	47.3
Engineering and Infrastructure Solutions | Education
Revenue from External Customer [Line Items]
Revenues	116.5	105.0
Engineering and Infrastructure Solutions | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	960.6	809.3
Operations and Maintenance
Revenue from External Customer [Line Items]
Revenues	1,224.0	1,167.2
Operations and Maintenance | B&I
Revenue from External Customer [Line Items]
Revenues	841.0	858.9
Operations and Maintenance | M&D
Revenue from External Customer [Line Items]
Revenues	213.5	156.1
Operations and Maintenance | Aviation
Revenue from External Customer [Line Items]
Revenues	52.9	47.3
Operations and Maintenance | Education
Revenue from External Customer [Line Items]
Revenues	116.5	105.0
Operations and Maintenance | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Building & Energy Solutions
Revenue from External Customer [Line Items]
Revenues	967.4	809.3
Building & Energy Solutions | B&I
Revenue from External Customer [Line Items]
Revenues	5.3	0.0
Building & Energy Solutions | M&D
Revenue from External Customer [Line Items]
Revenues	1.5	0.0
Building & Energy Solutions | Aviation
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Building & Energy Solutions | Education
Revenue from External Customer [Line Items]
Revenues	0.0	0.0
Building & Energy Solutions | Technical Solutions
Revenue from External Customer [Line Items]
Revenues	$ 960.6	$ 809.3