Commitments and Contingencies - Changes in Accrued Environmental Remediation and Related Costs (Detail) - USD ($) $ in Thousands |
12 Months Ended | |||||
|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Commitments And Contingencies Disclosure [Abstract] | ||||||
| Balance at the beginning of the year | $ 110,015 | $ 113,636 | $ 48,006 | |||
| Additions charged to expense, net | 4,370 | 6,485 | 68,929 | |||
| Payments, net | (1,252) | (10,106) | (3,299) | |||
| Balance at the end of the year | 113,133 | 110,015 | 113,636 | |||
| Amounts recognized in the Condensed Consolidated Balance Sheet at the end of the period: | ||||||
| Current liability | $ 8,668 | $ 6,984 | $ 4,859 | |||
| Noncurrent liability | 104,465 | 103,031 | 108,777 | |||
| Balance at the end of the year | $ 110,015 | $ 113,636 | $ 48,006 | $ 113,133 | $ 110,015 | $ 113,636 |