Summary of Significant Accounting Policies and Recent Accounting Pronouncements - Summary of Components of Inventory (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Raw materials	$ 53,875	$ 9,531
Work in progress	27,442	3,175
Finished goods	2,288	107
Total inventory	$ 83,605	$ 12,813

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of merchandise or goods held by the company that are readily available for sale.

+ References

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of unprocessed items to be consumed in the manufacturing or production process.

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The aggregate carrying amount, net of valuation reserves and adjustments, as of the balance sheet date of items which are partially completed at the time of measurement and unprocessed items that will go through the production process and become part of the final product. This element may be used when the reporting entity combines work in process and raw materials into an aggregate amount.

+ References

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