Restructuring (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Restructuring Reserve [Roll Forward]
Beginning balance			$ 0.4	$ 0.0
Charge to expense	$ 0.1	$ 0.0	0.4	1.2
Cash payments			(0.5)	(1.0)
Ending balance	0.3	$ 0.2	0.3	0.2
Operating Segments | Safety & Security Systems | Facility Closing [Member]
Restructuring Reserve [Roll Forward]
Charge to expense	$ 0.1		$ 0.4
Operating Segments | Safety & Security Systems | Voluntary Reduction-In-Force Plan
Restructuring Cost and Reserve [Line Items]
Severance costs				1.2
Restructuring Reserve [Roll Forward]
Charge to expense				$ 1.2