Income Taxes - Components of Net Deferred Tax Liability (Detail) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Tax effect of temporary differences related to: | ||
| Inventories | $ 500 | $ 500 |
| Accrued OPEB costs | 1,000 | 1,100 |
| Accrued pension costs | 4,200 | 4,600 |
| Accrued employee benefits | 1,900 | 2,000 |
| Accrued environmental liabilities | 41,100 | 39,900 |
| Other accrued liabilities and deductible differences | 200 | 400 |
| Tax loss and tax credit carryforwards | 500 | |
| Adjusted gross deferred tax assets (liabilities) | 48,900 | 49,000 |
| Netting of items by tax jurisdiction | (48,900) | (49,000) |
| Marketable securities | (17,000) | (6,400) |
| Property and equipment | (4,400) | (4,500) |
| Goodwill | (2,600) | (2,600) |
| Other taxable differences | (3,300) | (4,300) |
| Investment in Kronos Worldwide, Inc. | (49,000) | (56,200) |
| Adjusted gross deferred tax assets (liabilities) | (76,300) | (74,000) |
| Netting of items by tax jurisdiction | 48,900 | 49,000 |
| Net noncurrent deferred tax asset (liability) | $ (27,445) | $ (25,035) |