Commitments, Contingencies and Legal Proceedings - Schedule of Reserves (Detail) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Environmental Remediation Obligations [Abstract] | ||
| Beginning balance | $ 17,105 | $ 16,223 |
| Payments | (4,317) | (9,118) |
| Accruals | 40,000 | 10,000 |
| Ending balance | $ 52,788 | $ 17,105 |
| X | ||||||||||
- Definition Total costs accrued as of the balance sheet date for environmental loss contingencies. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of expense for newly incurred environmental loss contingencies. Includes, but is not limited to, remediation expense and interest accretion. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- Definition Amount of cash outflow to settle environmental loss contingencies. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
- References No definition available.
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