Discontinued Operations and Disposition - Additional Information (Detail) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Mar. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Impairment loss	$ 10,082
ASW Steel Inc [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net sales		$ 10,008	$ 14,044	$ 25,053	$ 36,378
ASW Steel Inc [Member] | Union Electric Steel Corporation [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Net sales		$ 883	$ 4,988	$ 4,021	$ 18,660