Discontinued Operations and Disposition - Summary of Assets and Liabilities of ASW (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Cash and cash equivalents	$ 948		$ 1,233
Current assets of discontinued operations	14,047	$ 20,238
Current liabilities of discontinued operations	8,342	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	948	1,124
Receivables	4,498	6,928
Inventories	10,446	13,764
Other assets	1,353	1,708
Property, plant and equipment, net	11,802	11,714
Estimated charge for impairment	(15,000)	(15,000)
Current assets of discontinued operations	14,047	20,238
Accounts payable	7,925	8,890
Accrued payrolls and employee benefits	141	178
Other current liabilities	276	390
Current liabilities of discontinued operations	$ 8,342	$ 9,458