Overview, Basis of presentation, Significant Accounting Policies and Recently Issued Accounting Guidance (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net sales	$ 381.4	$ 388.2	$ 393.6	$ 368.8	$ 362.5	$ 343.7	$ 307.6	$ 295.8	$ 1,532.0	$ 1,309.6	$ 1,187.7
Cost of sales									1,053.0	865.3	791.9
Accounts receivable, less allowance for doubtful accounts of $4.1 in 2018 and of $4.7 in 2017	286.6				261.7				286.6	261.7
Inventories	233.1				204.1				233.1	204.1
Adoption of accounting standard									(0.3)	0.2
Foreign currency transaction gains (losses)									1.8	(1.2)	(1.5)
Total research and development expenditures									30.2	32.7	$ 28.9
Accounts receivable, net (contract revenue recognized in excess of billings)	63.9				51.8				63.9	51.8
Retentions	0.7				0.3				0.7	0.3
Long-term retentions	$ 0.7				$ 0.9				$ 0.7	$ 0.9
Percentage of inventories were valued by the LIFO method	36.00%				34.00%				36.00%	34.00%
Net pension gain loss amortization threshold percent									10.00%
Right-of-use asset and lease liability	$ 25.0								$ 25.0
Statutory federal income tax rate									21.00%	35.00%	35.00%
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Minimum percentage of tax benefit, recognition threshold for the tax position	50.00%								50.00%
Building Improvements | Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, in years									5 years
Building Improvements | Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, in years									25 years
Machinery and Equipment | Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, in years									3 years
Machinery and Equipment | Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, in years									10 years
Accounts receivable, net (contract revenue recognized in excess of billings)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable, net (contract revenue recognized in excess of billings)	$ 61.1				$ 51.8				$ 61.1	$ 51.8
Finite-Lived Intangible Assets | Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible assets estimated useful lives, minimum, in years									2 years
Finite-Lived Intangible Assets | Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Intangible assets estimated useful lives, minimum, in years									21 years
Accounting Standards Update 2014-09
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement, effect of change	0.4								$ 0.4
Net sales									2.1
Cost of sales									1.4
Accounts receivable, less allowance for doubtful accounts of $4.1 in 2018 and of $4.7 in 2017	2.1								2.1
Inventories	$ (1.4)								(1.4)
Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New accounting pronouncement, effect of change				$ 0.7
Accounting Standards Update 2017-07
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Adoption of accounting standard									$ 12.0	$ 0.5	$ 2.2