Composition of Certain Balance Sheet Accounts - Other Non-Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other Liabilities, Noncurrent [Abstract]
Deferred revenue	$ 30,293	$ 73,192
Deferred rent	37,152	37,354
Asset retirement obligations	9,869	9,668
Deferred tax liabilities	2,120	5,983
Other	8,112	8,458
Total other non-current liabilities	$ 87,546	$ 134,655

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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For a classified balance sheet, the cumulative difference between the rental income or payments required by a lease agreement and the rental income or expense recognized on a straight-line basis, or other systematic and rational basis more representative of the time pattern in which use or benefit is granted or derived from the leased property, expected to be recognized in income or expense, by the lessor or lessee, respectively, more than one year after the balance sheet date.

+ References

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The noncurrent portion of deferred revenue amount as of balance sheet date. Deferred revenue is a liability related to a revenue producing activity for which revenue has not yet been recognized, and is not expected to be recognized in the next twelve months. 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.

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Amount, after deferred tax asset, of deferred tax liability attributable to taxable differences, with jurisdictional netting, and liabilities classified as noncurrent and other.

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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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