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Commitments and Contingencies (Additional Information) (Detail) $ in Thousands |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Apr. 21, 2014 USD ($) | Oct. 31, 2016 USD ($) | Mar. 31, 2017 USD ($) settlement | Dec. 31, 2015 USD ($) | Dec. 31, 2013 USD ($) | Dec. 31, 2016 USD ($)
Environmental Loss Contingencies [Line Items] |  |  |  |  |  |
Environmental Loss contingency accrual |  |  | $ 48,217 |  |  | $ 48,817
Pending Litigation [Member] |  |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |  |
Maximum Expected Damages |  | $ 167 |  |  |  |
LDEQ [Member] | Settled Litigation [Member] |  |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |  |
Number of claims settled | settlement |  |  | 2 |  |  |
Amount of settlement for compliance violations |  |  | $ 192 |  |  |
LDEQ [Member] | Pending Litigation [Member] |  |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |  |
Maximum Expected Damages |  |  | 100 |  |  |
Natrium [Member] | Axiall Corporation [Member] | Settled Litigation [Member] |  |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |  |
Payments for environmental loss contingencies |  |  |  |  | $ 449 |
Lake Charles, Louisiana [Member] | Axiall Corporation [Member] | Environmental Protection Agency [Member] | Settled Litigation [Member] |  |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |  |
Amount of settlement for compliance violations |  |  |  | $ 878 |  |
Culvert City, Kentucky and Lakes Charles, Louisiana [Member] | Environmental Protection Agency [Member] | Pending Litigation [Member] |  |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |  |
Maximum Expected Damages | $ 100 |  |  |  |  |
Maximum [Member] |  |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |  |
Environmental Exit Costs, Reasonably Possible Additional Loss |  |  | 80 |  |  |
Minimum [Member] |  |  |  |  |  |
Environmental Loss Contingencies [Line Items] |  |  |  |  |  |
Environmental Exit Costs, Reasonably Possible Additional Loss |  |  | $ 40 |  |  |

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