REVENUES FROM CONTRACTS - Disaggregated Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 02, 2021	Sep. 26, 2020	Oct. 02, 2021	Sep. 26, 2020
Disaggregation of Revenue [Line Items]
Revenues	$ 285.8	$ 268.3	$ 870.4	$ 783.1
Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues	248.6	236.8	767.3	675.2
Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues	37.2	31.5	103.1	107.9
Package and process cooling equipment and services
Disaggregation of Revenue [Line Items]
Revenues	104.1	107.9	317.5	320.0
Boilers, comfort heating, and ventilation
Disaggregation of Revenue [Line Items]
Revenues	75.2	74.9	223.0	191.2
Underground locators, inspection and rehabilitation equipment, and robotic systems
Disaggregation of Revenue [Line Items]
Revenues	60.1	52.0	193.4	148.0
Communication technologies, obstruction lighting, and bus fare collection systems
Disaggregation of Revenue [Line Items]
Revenues	46.3	33.2	135.8	121.2
South African projects
Disaggregation of Revenue [Line Items]
Revenues	0.1	0.3	0.7	2.7
HVAC
Disaggregation of Revenue [Line Items]
Revenues	179.3	182.6	540.3	510.6
HVAC \| Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues	154.1	160.6	474.8	429.6
HVAC \| Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues	25.2	22.0	65.5	81.0
HVAC \| Package and process cooling equipment and services
Disaggregation of Revenue [Line Items]
Revenues	104.1	107.7	317.3	319.4
HVAC \| Boilers, comfort heating, and ventilation
Disaggregation of Revenue [Line Items]
Revenues	75.2	74.9	223.0	191.2
HVAC \| Underground locators, inspection and rehabilitation equipment, and robotic systems
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
HVAC \| Communication technologies, obstruction lighting, and bus fare collection systems
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
HVAC \| South African projects
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Detection and Measurement
Disaggregation of Revenue [Line Items]
Revenues	106.4	85.2	329.2	269.2
Detection and Measurement \| Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues	94.5	76.2	292.5	245.4
Detection and Measurement \| Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues	11.9	9.0	36.7	23.8
Detection and Measurement \| Package and process cooling equipment and services
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Detection and Measurement \| Boilers, comfort heating, and ventilation
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Detection and Measurement \| Underground locators, inspection and rehabilitation equipment, and robotic systems
Disaggregation of Revenue [Line Items]
Revenues	60.1	52.0	193.4	148.0
Detection and Measurement \| Communication technologies, obstruction lighting, and bus fare collection systems
Disaggregation of Revenue [Line Items]
Revenues	46.3	33.2	135.8	121.2
Detection and Measurement \| South African projects
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Other
Disaggregation of Revenue [Line Items]
Revenues	0.1	0.5	0.9	3.3
Other \| Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.2
Other \| Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues	0.1	0.5	0.9	3.1
Other \| Package and process cooling equipment and services
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.2	0.2	0.6
Other \| Boilers, comfort heating, and ventilation
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Other \| Underground locators, inspection and rehabilitation equipment, and robotic systems
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Other \| Communication technologies, obstruction lighting, and bus fare collection systems
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Other \| South African projects
Disaggregation of Revenue [Line Items]
Revenues	$ 0.1	$ 0.3	$ 0.7	$ 2.7