Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|
Mar. 31, 2015 |
Jun. 30, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
Jun. 30, 2015 |
|
| Income Tax Disclosure [Line Items] | ||||||
| U.S. federal statutory income tax rate | 35.00% | 35.00% | 35.00% | |||
| Dividends received from Kronos Worldwide, Inc. | $ 21,132 | $ 21,132 | $ 21,132 | |||
| Adjustment to the reserve for uncertain tax positions, net | $ 3,000 | |||||
| Benefit over effective income tax rate | 12,200 | 15,200 | 15,200 | |||
| Canadian Income Tax Audit | ||||||
| Income Tax Disclosure [Line Items] | ||||||
| Adjustment to the reserve for uncertain tax positions, net | $ 3,000 | |||||
| U.S. Income Tax Audit | ||||||
| Income Tax Disclosure [Line Items] | ||||||
| Adjustment to the reserve for uncertain tax positions, net | $ 3,100 | |||||
| Kronos | ||||||
| Income Tax Disclosure [Line Items] | ||||||
| Dividends received from Kronos Worldwide, Inc. | 21,100 | $ 21,100 | $ 21,100 | |||
| Deferred income tax asset valuation allowance | $ 8,700 | $ 150,300 | ||||