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DEBT AND FINANCING ARRANGEMENTS - Narrative (Details) $ / shares in Units, $ in Thousands			1 Months Ended	2 Months Ended	12 Months Ended
	Apr. 01, 2024 USD ($) numberOfDays $ / shares	Sep. 22, 2020 USD ($) $ / shares	Apr. 30, 2024 USD ($)	Mar. 04, 2026 USD ($)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)	Sep. 30, 2025 USD ($)	Feb. 29, 2024	Nov. 30, 2022	Apr. 30, 2022 USD ($)	Mar. 31, 2022 USD ($)
Debt Instrument [Line Items]
Debt Instrument, Increase, Accrued Interest					$ 1,800	$ 1,900
Interest Expense, Nonoperating					10,600	(8,900)	$ (6,200)
Investment Income, Interest					2,700	3,400	3,800
Debt instrument, face amount					$ 230,000
Debt Instrument, Interest Rate, Stated Percentage					1.00%
Accumulated deficit					$ (1,404,064)	(1,300,576)
Other Long-Term Debt					40,070	0
Option Indexed to Issuer's Equity, Strike Price | $ / shares		$ 85.14
Option Indexed to Issuer's Equity, Cap Price | $ / shares		$ 128.51
Proceeds from termination of capped calls related to convertible notes					0	115	0
Gain on debt extinguishment					0	13,017	$ 0
Debt Instrument, Unused Borrowing Capacity, Amount					8,500
2020 Convertible Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount					230,000
Debt issuance costs, gross					5,572	5,572
Debt issuance costs, net					$ 0	$ 207
Debt instrument, interest rate					1.64%	1.64%
Debt Instrument, Interest Rate, Stated Percentage					1.00%
Interest Expense, Debt					$ 533	$ 1,506
Convertible Senior Notes, Additional Principal Option
Debt Instrument [Line Items]
Debt instrument, face amount		$ 30,000
Lines of Credit
Debt Instrument [Line Items]
Debt issuance costs, gross					1,333	1,211
Debt issuance costs, net					$ 149	221
Commitment fee percentage					0.15%
Lines of Credit | Line Of Credit 2018
Debt Instrument [Line Items]
Long-term finance lease liabilities					$ 40,100
Proceeds from Long-Term Lines of Credit					56,000
Repayments of Long-Term Lines of Credit					15,900
Lines of Credit | Line Of Credit 2018 | Subsequent Event
Debt Instrument [Line Items]
Repayments of Long-Term Lines of Credit				$ 10,000
Term loans
Debt Instrument [Line Items]
Long-term finance lease liabilities					$ 40,070	0
Convertible Debt | Convertible Senior Notes 2024
Debt Instrument [Line Items]
Debt instrument, face amount	$ 172,500
Debt Instrument, Interest Rate, Stated Percentage	4.25%
Debt Instrument, Convertible, Conversion Ratio	0.0554939
Conversion Price (in usd per share) | $ / shares	$ 18.02
Proceeds from issuance of convertible senior notes, net of issuance costs paid of $6,900	$ 166,800		$ 169,300
Debt Instrument, Face Amount, Additional Principal Available	$ 22,500
Convertible Debt | Convertible Senior Notes 2024 | Debt Conversion Terms One
Debt Instrument [Line Items]
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger	130.00%
Debt Instrument, Convertible, Threshold Consecutive Trading Days | numberOfDays	30
Debt Instrument, Convertible, Threshold Trading Days | numberOfDays	20
Convertible Debt | Convertible Senior Notes 2024 | Debt Conversion Terms Two
Debt Instrument [Line Items]
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger	98.00%
Debt Instrument, Convertible, Threshold Consecutive Trading Days | numberOfDays	10,000
Debt Instrument, Convertible, Consecutive Business Days After Threshold Trading Days	5 days
Convertible Debt | 2020 Convertible Senior Notes
Debt Instrument [Line Items]
Debt Instrument, Convertible, Conversion Ratio	0.0117457
Debt Instrument, Repurchased Face Amount			183,900					$ 46,100
Gain on debt extinguishment			13,000			13,000
Revolving Credit Facility | Lines of Credit | Line Of Credit 2018
Debt Instrument [Line Items]
Maximum borrowing capacity											$ 60,000	$ 50,000
Line of Credit Facility, Option To Increase Borrowing Capacity, Maximum											75,000
Debt Instrument, Covenant, Adjusted Cash, Minimum											$ 25,000
Debt Instrument, Maximum Borrowing Capacity, Eligible Accounts Receivable, Percentage									75.00%	50.00%	85.00%
Basis spread on variable rate					0.25%
Repayments of Long-Term Lines of Credit			$ 30,000
Interest Expense, Debt					$ 1,500	$ 700
Debt Instrument, Increase Upon Default, Interest Rate, Percentage									3.00%
Revolving Credit Facility | Lines of Credit | Amended Line Of Credit 2018
Debt Instrument [Line Items]
Basis spread on variable rate					0.125%
Revolving Credit Facility | Lines of Credit | Amended Line Of Credit 2018 | United States
Debt Instrument [Line Items]
Debt Instrument, Maximum Borrowing Capacity, Eligible Accounts Receivable, Percentage					85.00%
Revolving Credit Facility | Lines of Credit | Amended Line Of Credit 2018 | United Kingdom
Debt Instrument [Line Items]
Debt Instrument, Maximum Borrowing Capacity, Eligible Accounts Receivable, Percentage					30.00%

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