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Statement - CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) link:presentationLink link:calculationLink link:definitionLink 9952158 - Disclosure - ORGANIZATION link:presentationLink link:calculationLink link:definitionLink 9952159 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES link:presentationLink link:calculationLink link:definitionLink 9952160 - Disclosure - REVENUE link:presentationLink link:calculationLink link:definitionLink 9952161 - Disclosure - CASH AND RESTRICTED CASH link:presentationLink link:calculationLink link:definitionLink 9952162 - Disclosure - PROPERTY AND EQUIPMENT link:presentationLink link:calculationLink link:definitionLink 9952163 - Disclosure - HOSTING ARRANGEMENTS link:presentationLink link:calculationLink link:definitionLink 9952164 - Disclosure - GOODWILL AND INTANGIBLE ASSETS link:presentationLink link:calculationLink link:definitionLink 9952165 - Disclosure - EQUITY INVESTMENTS link:presentationLink link:calculationLink link:definitionLink 9952166 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES link:presentationLink link:calculationLink link:definitionLink 9952167 - Disclosure - LEASES link:presentationLink link:calculationLink link:definitionLink 9952168 - Disclosure - SHAREHOLDERS' EQUITY link:presentationLink link:calculationLink link:definitionLink 9952169 - Disclosure - STOCK-BASED COMPENSATION link:presentationLink link:calculationLink link:definitionLink 9952170 - Disclosure - INCOME TAXES link:presentationLink link:calculationLink link:definitionLink 9952171 - Disclosure - DEBT link:presentationLink link:calculationLink link:definitionLink 9952172 - Disclosure - COMMITMENTS link:presentationLink link:calculationLink link:definitionLink 9952173 - Disclosure - CONTINGENCIES link:presentationLink link:calculationLink link:definitionLink 9952174 - Disclosure - FAIR VALUE MEASUREMENTS link:presentationLink link:calculationLink link:definitionLink 9952175 - Disclosure - RELATED PARTY TRANSACTIONS link:presentationLink link:calculationLink link:definitionLink 9952176 - Disclosure - BENEFIT PLANS link:presentationLink link:calculationLink link:definitionLink 9952177 - Disclosure - SEGMENT INFORMATION link:presentationLink link:calculationLink link:definitionLink 9952178 - Disclosure - RESTRUCTURING ACTIVITIES link:presentationLink link:calculationLink link:definitionLink 9955511 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Policies) link:presentationLink link:calculationLink link:definitionLink 9955512 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES (Tables) link:presentationLink link:calculationLink link:definitionLink 9955513 - Disclosure - REVENUE (Tables) link:presentationLink link:calculationLink link:definitionLink 9955514 - Disclosure - CASH AND RESTRICTED CASH (Tables) link:presentationLink link:calculationLink link:definitionLink 9955515 - Disclosure - PROPERTY AND EQUIPMENT (Tables) link:presentationLink link:calculationLink link:definitionLink 9955516 - Disclosure - HOSTING ARRANGEMENTS (Tables) link:presentationLink link:calculationLink link:definitionLink 9955517 - 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Disclosure - RESTRUCTURING ACTIVITIES (Tables) link:presentationLink link:calculationLink link:definitionLink 9955527 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES - Schedule of Reconciliation of the Allowance for Doubtful Accounts (Details) link:presentationLink link:calculationLink link:definitionLink 9955528 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955529 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES - Schedule of Depreciation Period for Each Asset Category (Details ) link:presentationLink link:calculationLink link:definitionLink 9955530 - Disclosure - SIGNIFICANT ACCOUNTING POLICIES - Cumulative Effect for Adoption of ASU 2020-06 (Details) link:presentationLink link:calculationLink link:definitionLink 9955531 - Disclosure - REVENUE (Details) link:presentationLink link:calculationLink link:definitionLink 9955532 - Disclosure - CASH AND RESTRICTED CASH (Details) link:presentationLink link:calculationLink link:definitionLink 9955533 - Disclosure - PROPERTY AND EQUIPMENT - Schedule of Property and Equipment, Net (Details) link:presentationLink link:calculationLink link:definitionLink 9955534 - Disclosure - PROPERTY AND EQUIPMENT - Additional Information (Details) link:presentationLink link:calculationLink link:definitionLink 9955535 - Disclosure - HOSTING ARRANGEMENTS (Details) link:presentationLink link:calculationLink link:definitionLink 9955536 - Disclosure - GOODWILL AND INTANGIBLE ASSETS - Goodwill and Intangible Assets (Details) link:presentationLink link:calculationLink link:definitionLink 9955537 - Disclosure - GOODWILL AND INTANGIBLE ASSETS - Definite Lived Intangibles (Details) link:presentationLink link:calculationLink link:definitionLink 9955538 - Disclosure - GOODWILL AND INTANGIBLE ASSETS - Definite Lived Intangibles Amortization (Details) link:presentationLink link:calculationLink link:definitionLink 9955539 - Disclosure - EQUITY INVESTMENTS (Details) link:presentationLink link:calculationLink link:definitionLink 9955540 - Disclosure - ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES (Details) link:presentationLink link:calculationLink link:definitionLink 9955541 - Disclosure - LEASES (Details) link:presentationLink link:calculationLink link:definitionLink 9955541 - Disclosure - LEASES (Details) link:presentationLink link:calculationLink link:definitionLink 9955542 - Disclosure - SHAREHOLDERS' EQUITY (Details) link:presentationLink link:calculationLink link:definitionLink 9955543 - Disclosure - STOCK-BASED COMPENSATION - Plan Information and P&L Impact (Details) link:presentationLink link:calculationLink link:definitionLink 9955544 - Disclosure - STOCK-BASED COMPENSATION - Schedule of Non-Cash Compensation Expense Related to Equity Awards (Details) link:presentationLink link:calculationLink link:definitionLink 9955545 - Disclosure - STOCK-BASED COMPENSATION - Schedules - Stock Options (Details) link:presentationLink link:calculationLink link:definitionLink 9955546 - Disclosure - STOCK-BASED COMPENSATION - Narrative - Stock Options (Details) link:presentationLink link:calculationLink link:definitionLink 9955547 - Disclosure - STOCK-BASED COMPENSATION - RSU and RSA Activity (Details) link:presentationLink link:calculationLink link:definitionLink 9955548 - Disclosure - STOCK-BASED COMPENSATION - Schedule of RSUs with Market Conditions Valuation Assumptions (Details) link:presentationLink link:calculationLink link:definitionLink 9955549 - Disclosure - STOCK-BASED COMPENSATION - Employee Stock Purchase Plan (Details) link:presentationLink link:calculationLink link:definitionLink 9955550 - Disclosure - INCOME TAXES - Income Tax Expense (Benefit) Components (Details) link:presentationLink link:calculationLink link:definitionLink 9955551 - Disclosure - INCOME TAXES - Income Tax Reconciliation when Applying the Statutory Federal Tax Rate (Details) link:presentationLink link:calculationLink link:definitionLink 9955552 - Disclosure - INCOME TAXES - Deferred Income Taxes - Components (Details) link:presentationLink link:calculationLink link:definitionLink 9955553 - Disclosure - INCOME TAXES - Deferred Income Taxes - BS Presentation (Details) link:presentationLink link:calculationLink link:definitionLink 9955554 - Disclosure - INCOME TAXES - Valuation Allowance (Details) link:presentationLink link:calculationLink link:definitionLink 9955555 - Disclosure - INCOME TAXES - Unrecognized Tax Benefits (Details) link:presentationLink link:calculationLink link:definitionLink 9955556 - Disclosure - DEBT - Convertible Senior Notes (Details) link:presentationLink link:calculationLink link:definitionLink 9955557 - Disclosure - DEBT - Schedule of Component of the Notes (Details) link:presentationLink link:calculationLink link:definitionLink 9955558 - Disclosure - DEBT - Convertible Note Hedge and Warrant Transactions (Details) link:presentationLink link:calculationLink link:definitionLink 9955559 - Disclosure - DEBT - 2021 Credit Facility and 2024 Term Loan (Details) link:presentationLink link:calculationLink link:definitionLink 9955560 - Disclosure - DEBT - Schedule of Current and Long-Term Portion of Debt (Details) link:presentationLink link:calculationLink link:definitionLink 9955561 - 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