Income Taxes - Components of Net Deferred Tax Liability (Detail) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Tax effect of temporary differences related to: | ||
| Inventories | $ 500 | $ 800 |
| Accrued OPEB costs | 1,100 | 1,400 |
| Accrued pension costs | 4,600 | 4,400 |
| Accrued employee benefits | 2,000 | 1,900 |
| Accrued environmental liabilities | 39,900 | 38,800 |
| Other accrued liabilities and deductible differences | 400 | 800 |
| Tax loss and tax credit carryforwards | 500 | 2,200 |
| Adjusted gross deferred tax assets (liabilities) | 49,000 | 50,300 |
| Netting of items by tax jurisdiction | (49,000) | (50,300) |
| Marketable securities | (6,400) | (31,900) |
| Property and equipment | (4,500) | (4,600) |
| Goodwill | (2,600) | (2,600) |
| Other taxable differences | (4,300) | (4,200) |
| Investment in Kronos Worldwide, Inc. | (56,200) | (90,100) |
| Adjusted gross deferred tax assets (liabilities) | (74,000) | (133,400) |
| Netting of items by tax jurisdiction | 49,000 | 50,300 |
| Net noncurrent deferred tax asset (liability) | $ (25,035) | $ (83,158) |