Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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Amount of expense (reversal of expense) for expected credit loss on accounts receivable.

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Revenue - Net Sales and (Loss) Income from Continuing Operations before Income Taxes (Detail) (parenthetical) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Impairment charge	$ 0		$ 0	$ 10,082	$ 0
Akers National Roll Company [Member]
Disaggregation Of Revenue [Line Items]
Impairment charge		$ 10,082
Forged and Cast Engineered Products [Member]
Disaggregation Of Revenue [Line Items]
Bad debt expenses				$ 1,366