REVENUES FROM CONTRACTS - Disaggregated Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Disaggregation of Revenue [Line Items]
Revenues	$ 363.4	$ 364.8	$ 1,105.9	$ 1,080.8
Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues	239.3	244.1	684.5	706.1
Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues	124.1	120.7	421.4	374.7
Cooling
Disaggregation of Revenue [Line Items]
Revenues	79.7	68.4	214.2	194.3
Boilers, comfort heating, and ventilation
Disaggregation of Revenue [Line Items]
Revenues	74.9	71.7	191.2	205.1
Underground locators, inspection and rehabilitation equipment, and robotic systems
Disaggregation of Revenue [Line Items]
Revenues	52.0	45.0	148.0	144.7
Signal monitoring, obstruction lighting, and bus fare collection systems
Disaggregation of Revenue [Line Items]
Revenues	33.2	52.6	121.2	139.7
Power transformers
Disaggregation of Revenue [Line Items]
Revenues	95.1	93.4	319.6	296.8
Process cooling equipment and services, and heat exchangers
Disaggregation of Revenue [Line Items]
Revenues	28.2	28.6	109.0	109.0
South African projects
Disaggregation of Revenue [Line Items]
Revenues	0.3	5.1	2.7	(8.8)
HVAC
Disaggregation of Revenue [Line Items]
Revenues	154.6	140.1	405.4	399.4
HVAC | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues	154.6	140.1	405.4	399.4
HVAC | Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
HVAC | Cooling
Disaggregation of Revenue [Line Items]
Revenues	79.7	68.4	214.2	194.3
HVAC | Boilers, comfort heating, and ventilation
Disaggregation of Revenue [Line Items]
Revenues	74.9	71.7	191.2	205.1
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 | Signal monitoring, obstruction lighting, and bus fare collection systems
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
HVAC | Power transformers
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
HVAC | Process cooling equipment and services, and heat exchangers
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	85.2	97.6	269.2	284.4
Detection and Measurement | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues	76.2	91.0	245.4	266.7
Detection and Measurement | Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues	9.0	6.6	23.8	17.7
Detection and Measurement | Cooling
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	52.0	45.0	148.0	144.7
Detection and Measurement | Signal monitoring, obstruction lighting, and bus fare collection systems
Disaggregation of Revenue [Line Items]
Revenues	33.2	52.6	121.2	139.7
Detection and Measurement | Power transformers
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Detection and Measurement | Process cooling equipment and services, and heat exchangers
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Detection and Measurement | South African projects
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Engineered Solutions
Disaggregation of Revenue [Line Items]
Revenues	123.1	121.1	424.8	398.1
Engineered Solutions | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues	8.4	12.6	31.6	38.0
Engineered Solutions | Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues	114.7	108.5	393.2	360.1
Engineered Solutions | Cooling
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Engineered Solutions | Boilers, comfort heating, and ventilation
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Engineered Solutions | Underground locators, inspection and rehabilitation equipment, and robotic systems
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Engineered Solutions | Signal monitoring, obstruction lighting, and bus fare collection systems
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
Engineered Solutions | Power transformers
Disaggregation of Revenue [Line Items]
Revenues	95.1	93.4	319.6	296.8
Engineered Solutions | Process cooling equipment and services, and heat exchangers
Disaggregation of Revenue [Line Items]
Revenues	28.0	27.7	105.2	101.3
Engineered Solutions | South African projects
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
All Other
Disaggregation of Revenue [Line Items]
Revenues	0.5	6.0	6.5	(1.1)
All Other | Transferred at Point in Time
Disaggregation of Revenue [Line Items]
Revenues	0.1	0.4	2.1	2.0
All Other | Transferred over Time
Disaggregation of Revenue [Line Items]
Revenues	0.4	5.6	4.4	(3.1)
All Other | Cooling
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
All Other | Boilers, comfort heating, and ventilation
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
All Other | Underground locators, inspection and rehabilitation equipment, and robotic systems
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
All Other | Signal monitoring, obstruction lighting, and bus fare collection systems
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
All Other | Power transformers
Disaggregation of Revenue [Line Items]
Revenues	0.0	0.0	0.0	0.0
All Other | Process cooling equipment and services, and heat exchangers
Disaggregation of Revenue [Line Items]
Revenues	0.2	0.9	3.8	7.7
All Other | South African projects
Disaggregation of Revenue [Line Items]
Revenues	$ 0.3	$ 5.1	$ 2.7	$ (8.8)