Discontinued Operations and Disposition - Summary of Assets and Liabilities of ASW (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Cash and cash equivalents	$ 395		$ 1,552
Current assets of discontinued operations	17,754	$ 20,238
Current liabilities of discontinued operations	9,786	9,458
ASW Steel Inc [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Cash and cash equivalents	395	1,124
Receivables	7,303	6,928
Inventories	11,780	13,764
Other assets	1,463	1,708
Property, plant and equipment, net	11,813	11,714
Estimated charge for impairment	(15,000)	(15,000)
Current assets of discontinued operations	17,754	20,238
Accounts payable	9,123	8,890
Accrued payrolls and employee benefits	140	178
Other current liabilities	523	390
Current liabilities of discontinued operations	$ 9,786	$ 9,458