SUPPLEMENTAL CONDENSED CONSOLIDATED BALANCE SHEETS AND STATEMENTS OF OPERATIONS INFORMATION - Schedule of Accrued Expense and Other Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Supplemental Consolidated Balance Sheet & Statement of Operations Information [Abstract]
Refund reserve	$ 22,239	$ 33,173
Compensation and benefits	24,625	54,958
Accrued marketing	21,388	15,299
Restructuring-related liabilities	10,001	13,746
Customer credits	78,217	61,006
Income taxes payable	1,182	7,862
Deferred revenue	3,868	11,223
Operating and finance lease obligations	32,836	37,755
Deferred cloud computing contract incentive	3,000	3,000
Other	44,381	56,977
Total accrued expenses and other current liabilities	241,737	294,999
Accrued payroll taxes, CARES Act	$ 2,900	$ 2,900

Accrued Payroll Taxes, Current, CARES Act

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- Definition

Credits to customers that can be applied to future purchases on our online marketplaces. Credits are primarily issued for refunds or for customer relationship purposes.

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- Definition

Deferred Costs, Cloud Computing Contract Incentives, Current

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- Definition

Lease Liability, Current

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- Definition

Supplemental Consolidated Balance Sheet & Statement of Operations Information [Abstract]

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Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for the marketing, trade and selling of the entity's goods and services. Marketing costs would include expenditures for planning and executing the conception, pricing, promotion, and distribution of ideas, goods, and services; costs of public relations and corporate promotions; and obligations incurred and payable for sales discounts, rebates, price protection programs, etc. offered to customers and under government programs. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Current regulatory liabilities generally represent obligations to make refunds to customers for various reasons including overpayment.

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- Definition

Amount of deferred income and obligation to transfer product and service to customer for which consideration has been received or is receivable.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Amount of expenses incurred but not yet paid classified as other, due within 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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- Definition

Carrying amount as of the balance sheet date of known and estimated obligations associated with exit from or disposal of business activities or restructurings pursuant to a duly authorized plan, which are expected to be paid in the next twelve months or in the normal operating cycle if longer. Costs of such activities include those for one-time termination benefits, termination of an operating lease or other contract, consolidating or closing facilities, relocating employees, and costs associated with an ongoing benefit arrangement, but excludes costs associated with the retirement of a long-lived asset.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(20))
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-Name Accounting Standards Codification
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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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