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CONVERTIBLE DEBT - Narrative (Details) $ / shares in Units, $ in Thousands			3 Months Ended
	Jun. 02, 2020 USD ($) day $ / shares	Sep. 13, 2019 USD ($) $ / shares	Apr. 01, 2022 USD ($) day $ / shares	Dec. 31, 2021 USD ($) $ / shares	Sep. 25, 2020 USD ($)
Debt Instrument [Line Items]
Common stock, par value (in dollars per share) \| $ / shares			$ 0.001	$ 0.001
2022 Notes
Debt Instrument [Line Items]
Debt instrument principal amount			$ 37,707	$ 37,707
Fair value of 2022 Notes used to settle 2020 Notes	$ 44,400
Unamortized debt discount				672
2022 Notes \| Stock price greater or equal 130 percent of note conversion rate
Debt Instrument [Line Items]
Debt instrument threshold trading days \| day			20
Debt instrument threshold consecutive trading days \| day			30
2022 Notes \| Senior notes
Debt Instrument [Line Items]
Debt instrument principal amount	$ 37,700		$ 37,500
Debt instrument stated percentage (as a percent)	4.375%
Common stock, par value (in dollars per share) \| $ / shares	$ 0.001
Debt instrument conversion ratio	173.9978
Debt instrument conversion price (in dollars per share) \| $ / shares	$ 5.75
Carrying amount of equity component	$ 8,300
Convertible debt	36,000
Unamortized debt discount	$ 1,700
2022 Notes \| Senior notes \| Stock price greater or equal 130 percent of note conversion rate
Debt Instrument [Line Items]
Debt instrument threshold trading days \| day	20
Debt instrument threshold consecutive trading days \| day	30
Debt instrument threshold percentage of stock price trigger (as a percent)	130.00%		130.00%
2022 Notes \| Senior notes \| Note price less than 98 percent of stock price times conversion rate
Debt Instrument [Line Items]
Debt instrument threshold trading days \| day	5
Debt instrument threshold consecutive trading days \| day	5
Debt instrument threshold percentage of stock price trigger (as a percent)	98.00%
2024 Notes
Debt Instrument [Line Items]
Debt instrument principal amount			$ 115,500	115,500
Unamortized debt discount				$ 14,576
2024 Notes \| Senior notes
Debt Instrument [Line Items]
Debt instrument principal amount		$ 115,500
Debt instrument stated percentage (as a percent)		2.00%
Common stock, par value (in dollars per share) \| $ / shares		$ 0.001
Debt instrument conversion ratio		115.5001
Debt instrument conversion price (in dollars per share) \| $ / shares		$ 8.66
Carrying amount of equity component					$ 24,900