Description of the Business and Significant Accounting Policies (Segments) (Details) - segment	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information
Number of reporting segments			3
Steel Operations
Segment Reporting Information
Percentage of external net sales	78.00%	76.00%	76.00%	76.00%
Metals Recycling Operations
Segment Reporting Information
Percentage of external net sales	7.00%	12.00%	10.00%	12.00%
Steel Fabrication Operations
Segment Reporting Information
Percentage of external net sales	10.00%	9.00%	9.00%	8.00%