Special Charges, Net (Details) $ in Millions		12 Months Ended
		Dec. 31, 2017 USD ($) employee	Dec. 31, 2016 USD ($) employee	Dec. 31, 2015 USD ($) employee
Special charges, net
Period for selling an asset		1 year
Period for settling liabilities		1 year
Restructuring charges
Employee Termination Costs		$ 2.5	$ 1.7	$ 4.5
Facility Consolidation Costs		0.0	0.0	0.2
Other Cash Costs, Net		0.2	0.0	0.1
Non-Cash Asset Write-downs		0.0	3.6	0.3
Total Special Charges		2.7	5.3	5.1
Asset impairment charges		0.0	30.1	0.0
Restructuring liabilities
Balance at beginning of year		0.9	1.6	1.7
Special charges	[1]	2.7	1.7	4.8
Utilization — cash		(3.0)	(2.1)	(5.1)
Currency translation adjustment and other		0.0	(0.3)	0.2
Balance at the end of year		0.6	0.9	1.6
Asset impairment charges		0.0	$ 3.6	0.3
Corporate
Restructuring charges
Employee Termination Costs		0.1		1.1
Total Special Charges		$ 0.1		$ 1.1
Number of employees expected to be terminated | employee		4
HVAC segment
Restructuring charges
Number of employees terminated | employee		12		44
HVAC segment | Reportable and other operating segments
Restructuring charges
Employee Termination Costs		$ 0.4		$ 0.9
Facility Consolidation Costs				0.1
Other Cash Costs, Net				(0.2)
Non-Cash Asset Write-downs				0.3
Total Special Charges		$ 0.4		$ 1.1
Detection and Measurement segment
Restructuring charges
Number of employees terminated | employee		8	19	21
Detection and Measurement segment | Reportable and other operating segments
Restructuring charges
Employee Termination Costs		$ 0.3	$ 0.5	$ 0.9
Non-Cash Asset Write-downs			0.3
Total Special Charges		$ 0.3	$ 0.8	$ 0.9
Engineered Solutions segment
Restructuring charges
Number of employees terminated | employee				134
Number of employees expected to be terminated | employee		111	97
Engineered Solutions segment | Reportable and other operating segments
Restructuring charges
Employee Termination Costs		$ 1.7	$ 1.2	$ 1.6
Facility Consolidation Costs				0.1
Other Cash Costs, Net		0.2		0.3
Non-Cash Asset Write-downs			3.3
Total Special Charges		$ 1.9	4.5	$ 2.0
Engineered Solutions segment | SPX Heat Transfer Business
Restructuring charges
Asset impairment charges			$ 3.3

[1] The years ended December 31, 2017, 2016 and 2015 excluded $0.0, $3.6 and $0.3, respectively, of non-cash charges that impacted special charges but not the restructuring liabilities.