Description of the Business and Summary of Significant Accounting Policies (Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Goodwill
Goodwill	$ 453,835	$ 457,226
Goodwill impairment loss	0	0	$ 0
Compensation expense for stock-based employee compensation plan	80,200	50,700	$ 43,300
Steel Operations
Goodwill
Goodwill	272,133	272,133
Metals Recycling Operations
Goodwill
Goodwill	179,777	183,168
Metals Recycling Operations \| OmniSource
Goodwill
Goodwill decrease due to tax benefit related to the normal amortization of the component	3,400
Goodwill impaired accumulated impairment loss	346,800	346,800
Steel Fabrication Operations
Goodwill
Goodwill	$ 1,925	$ 1,925

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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