Description of the Business and Significant Accounting Policies (Segments) (Details) - segment	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information
Number of reporting segments	3
Steel Operations
Segment Reporting Information
Percentage of external net sales	75.00%	75.00%
Metals Recycling Operations
Segment Reporting Information
Percentage of external net sales	11.00%	13.00%
Steel Fabrication Operations
Segment Reporting Information
Percentage of external net sales	9.00%	8.00%