Industry Segments and Geographic Area Information - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) group	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Concentration Risk [Line Items]
Export sales from United States | $	$ 217.2	$ 213.8	$ 224.9
Net Sales Total | Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%	10.00%	11.00%
Long-lived assets Total | Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%	10.00%	10.00%
Canada | Net Sales Total | Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	31.00%
Canada | Long-lived assets Total | Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	16.00%
United Kingdom | Net Sales Total | Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	21.00%
United Kingdom | Long-lived assets Total | Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	31.00%
BRAZIL | Net Sales Total | Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%
MEXICO | Long-lived assets Total | Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	19.00%
Electrical
Concentration Risk [Line Items]
Number Of business groups | group	3