Commitments and Contingencies - Changes in Accrued Environmental Remediation and Related Costs (Detail) - USD ($) $ in Thousands |
12 Months Ended | |||||
|---|---|---|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Commitments And Contingencies Disclosure [Abstract] | ||||||
| Balance at the beginning of the year | $ 113,133 | $ 110,015 | $ 113,636 | |||
| Additions charged to expense, net | 5,152 | 4,370 | 6,485 | |||
| Payments, net | (1,627) | (1,252) | (10,106) | |||
| Balance at the end of the year | 116,658 | 113,133 | 110,015 | |||
| Amounts recognized in the Condensed Consolidated Balance Sheet at the end of the period: | ||||||
| Current liability | $ 13,350 | $ 8,668 | $ 6,984 | |||
| Noncurrent liability | 103,308 | 104,465 | 103,031 | |||
| Balance at the end of the year | $ 113,133 | $ 110,015 | $ 113,636 | $ 116,658 | $ 113,133 | $ 110,015 |