Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 02, 2018	Jan. 01, 2018
Notes receivable and other long-term assets, net	$ 31,622	$ 17,470	$ 21,397	$ 20,434
Deferred Revenue	7,338	7,361	3,432	3,762
Retained Earnings (Accumulated Deficit)	(668,232)	(688,653)	(683,570)	$ (684,863)
Difference between Revenue Guidance in Effect before and after Topic 606
Notes receivable and other long-term assets, net					$ (963)
Deferred Revenue					330
Retained Earnings (Accumulated Deficit)					$ (1,293)
Commodity Swap And Customer Contract [Member]
Total gain (loss)	$ (6,600)	$ 10,300	$ 0

The amount of notes receivable and other long-term assets, net.

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Amount of deferred revenue as of balance sheet date. Deferred revenue represents collections of cash or other assets related to a revenue producing activity for which revenue has not yet been recognized. Generally, an entity records deferred revenue when it receives consideration from a customer before achieving certain criteria that must be met for revenue to be recognized in conformity with GAAP.

+ References

No definition available.

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Amount of gain (loss) recognized in the income statement for financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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- Definition

The cumulative amount of the reporting entity's undistributed earnings or deficit.

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