Segments (Percentage of Net Sales by Product Line) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Product Information [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%
Supply Technologies
Product Information [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%
Supply Technologies | Supply Technologies
Product Information [Line Items]
Percentage of net sales	85.00%	85.00%	87.00%
Supply Technologies | Engineered specialty products
Product Information [Line Items]
Percentage of net sales	15.00%	15.00%	13.00%
Assembly Components
Product Information [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%
Assembly Components | Fuel-related, rubber and plastic products
Product Information [Line Items]
Percentage of net sales	70.00%	67.00%	59.00%
Assembly Components | Aluminum products
Product Information [Line Items]
Percentage of net sales	30.00%	33.00%	41.00%
Engineered Products
Product Information [Line Items]
Percentage of net sales	100.00%	100.00%	100.00%
Engineered Products | Industrial equipment business
Product Information [Line Items]
Percentage of net sales	84.00%	79.00%	81.00%
Engineered Products | Forged and machined products
Product Information [Line Items]
Percentage of net sales	16.00%	21.00%	19.00%