Information on Reportable Segments (Details) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2017 USD ($) country	Sep. 30, 2017 USD ($)	Jul. 01, 2017 USD ($)	Apr. 01, 2017 USD ($)	Dec. 31, 2016 USD ($)	Oct. 01, 2016 USD ($)	Jul. 02, 2016 USD ($)	Apr. 02, 2016 USD ($)	Sep. 26, 2015 USD ($)	Dec. 31, 2017 USD ($) country segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Business segment
Number of countries in which entity operates | country	15									15
Number of reportable segments | segment										3
Revenues:
Revenues	$ 387.0	$ 348.5	$ 349.7	$ 340.6	$ 395.3	$ 345.0	$ 371.4	$ 360.6		$ 1,425.8	$ 1,472.3	$ 1,559.0
Income (loss):
Pension and other employee benefits										14.9	24.8	35.2
Special charges, net										2.7	5.3	5.1
Gain (loss) on sale										0.0	18.4	0.0
Operating income (loss)										54.8	55.0	(122.2)
Capital expenditures:
Total capital expenditures										11.0	11.7	16.0
Depreciation and amortization:
Total depreciation and amortization										25.2	26.5	37.0
Identifiable assets:
Total identifiable assets	2,040.4				1,912.5					2,040.4	1,912.5	2,179.3
Tangible Long-Lived Assets:
Total tangible long-lived assets	944.4				926.6					944.4	926.6	912.1
Gain on contract settlement										10.2	0.0	0.0
United States
Revenues:
Revenues										1,243.3	1,235.2	1,255.4
China
Revenues:
Revenues										28.0	33.5	83.6
South Africa
Revenues:
Revenues										56.9	105.4	54.2
United Kingdom
Revenues:
Revenues										60.8	59.1	69.6
Other
Revenues:
Revenues										36.8	39.1	96.2
Continuing operations
Tangible Long-Lived Assets:
Total tangible long-lived assets	944.4				926.6					944.4	926.6	876.3
Continuing operations | United States
Tangible Long-Lived Assets:
Total tangible long-lived assets	919.6				897.0					919.6	897.0	835.9
Continuing operations | Other
Tangible Long-Lived Assets:
Total tangible long-lived assets	24.8				29.6					24.8	29.6	40.4
Discontinued operations
Identifiable assets:
Total identifiable assets	0.0				0.0					0.0	0.0	120.0
Tangible Long-Lived Assets:
Total tangible long-lived assets	0.0				0.0					0.0	0.0	35.8
Reportable and other operating segments
Income (loss):
Operating income (loss)										124.9	142.8	38.8
General corporate
Income (loss):
Corporate expense										46.2	41.7	103.4
Special charges, net										0.1		1.1
Capital expenditures:
Total capital expenditures										1.9	2.6	4.4
Depreciation and amortization:
Total depreciation and amortization										3.1	2.5	8.9
Identifiable assets:
Total identifiable assets	457.7				390.6					457.7	390.6	371.2
Segment reconciling items
Income (loss):
Pension and other employee benefits										5.4	15.4	18.6
Long-term incentive compensation expense										15.8	13.7	33.9
Impairment of intangible and other long-term assets										0.0	30.1	0.0
Special charges, net										2.7	5.3	5.1
Gain (loss) on sale										0.0	18.4	0.0
HVAC segment
Revenues:
Revenues										511.0	509.5	529.1
HVAC segment | Reportable and other operating segments
Income (loss):
Special charges, net										0.4		1.1
Operating income (loss)										74.1	80.2	80.2
Capital expenditures:
Total capital expenditures										2.2	1.9	2.3
Depreciation and amortization:
Total depreciation and amortization										5.5	5.3	4.6
Identifiable assets:
Total identifiable assets	747.1				710.1					747.1	710.1	623.0
Detection and Measurement segment
Revenues:
Revenues										260.3	226.4	232.3
Detection and Measurement segment | Reportable and other operating segments
Income (loss):
Special charges, net										0.3	0.8	0.9
Operating income (loss)										63.4	45.3	46.0
Capital expenditures:
Total capital expenditures										0.8	0.7	1.2
Depreciation and amortization:
Total depreciation and amortization										4.1	3.5	2.8
Identifiable assets:
Total identifiable assets	277.8				244.2					277.8	244.2	256.5
Engineered Solutions segment
Revenues:
Revenues										654.5	736.4	797.6
Tangible Long-Lived Assets:
Proceeds from Contract Termination		9.0
Gain on contract settlement		$ 10.2
Engineered Solutions segment | Reportable and other operating segments
Income (loss):
Special charges, net										1.9	4.5	2.0
Operating income (loss)										(12.6)	17.3	(87.4)
Capital expenditures:
Total capital expenditures										6.1	6.5	8.1
Depreciation and amortization:
Total depreciation and amortization										12.5	15.2	20.7
Identifiable assets:
Total identifiable assets	$ 557.8				$ 567.6					$ 557.8	$ 567.6	808.6
Minimum
Business segment
Number of countries in which entity sells its products and services | country	100									100
Large Power Projects | Revisions in estimates for large power projects | South Africa
Revenues:
Revenues									$ (57.2)			$ (57.2)
Income (loss):
Operating income (loss)									$ (95.0)
Large Power Projects | Revisions in estimates for large power projects | Engineered Solutions segment | Reportable and other operating segments | South Africa
Revenues:
Revenues	$ (23.4)		(13.5)							$ (36.9)
Income (loss):
Operating income (loss)	$ (29.9)		$ (22.9)							$ (52.8)