Details Of Certain Accounts - Other Non-Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deferred revenue (Note 10)	$ 5,860	$ 8,286
Asset retirement obligations (Note 14)	28,934	28,258
Other	1,492	2,100
Total other non-current liabilities	$ 36,286	$ 38,644

Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of expenses incurred but not yet paid classified as other, due after one year or the normal operating cycle, if longer.

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Amount of liabilities classified as other, due after one year or the normal operating cycle, if longer.

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