Segment Information, Narrative (Details) - productionfacilities	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Segment Reporting Information
Percentage of Employees Covered by Collective Bargaining Agreements	63.00%		63.00%
Percentage of Employees Covered by Collective Bargaining Agreements Expiring Within One Year	6.00%		6.00%
United States
Segment Reporting Information
Number of production facilities			11
Canada
Segment Reporting Information
Number of production facilities			1
Customer Concentration Risk | Largest Customer | Sales Revenue, Net | Fabricated Products
Segment Reporting Information
Concentration Risk, Percentage	27.00%	25.00%	26.00%	26.00%
Customer Concentration Risk | Largest Customer | Accounts Receivable
Segment Reporting Information
Concentration Risk, Percentage			19.00%
Customer Concentration Risk | Second Largest Customer | Sales Revenue, Net | Fabricated Products
Segment Reporting Information
Concentration Risk, Percentage	10.00%	10.00%	10.00%	10.00%
Customer Concentration Risk | Second Largest Customer | Accounts Receivable
Segment Reporting Information
Concentration Risk, Percentage			13.00%		17.00%