Other Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Assets [Line Items]
Other	$ 784	$ 1,034
Other Assets, Total	5,424	5,194
Pic Onyx Inc
Other Assets [Line Items]
Investment in PicOnyx	128
PicOnyx promissory note	500
Bauxite raw materials
Other Assets [Line Items]
Inventories - bauxite raw materials	$ 4,012	$ 4,160

Other assets.

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- Definition

Promissory note

+ References

No definition available.

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- Definition

Sum of the carrying amounts as of the balance sheet date of all investments.

+ References

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Amount of asset related to consideration paid in advance for costs that provide economic benefits in future periods, and amount of other assets that are expected to be realized or consumed after one year or the normal operating cycle, if longer.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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