FAIR VALUE MEASUREMENTS (Tables)

3 Months Ended

Mar. 31, 2020

Fair Value Disclosures [Abstract]

Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents the Company’s assets and liabilities that were measured at fair value on a recurring basis and its categorization within the fair value hierarchy.

	March 31, 2020				December 31, 2019
	(In thousands)
	Level 2		Level 3		Level 2		Level 3
Assets:
Convertible notes hedge	$	47,885	$	—	$	—	$	—
Liabilities:
Debt, non-current
Convertible notes embedded derivative	45,100		—		—		—
Warrants liability	38,637		—		—		—
Warranty obligations
Current	—		6,578		—		6,794
Non-current	—		13,847		—		13,012
Total warranty obligations measured at fair value	—		20,425		—		19,806
Total liabilities measured at fair value	$	83,737	$	20,425	$	—	$	19,806

The following table presents the fair value and the change in fair value for Convertible notes hedge and Warrants liability (in thousands):

	Convertible notes hedge			Warrants liability
	(In thousands)
Fair value as of March 09, 2020	$	89,056		$	71,552
Change in the fair value	(41,171		)	(32,915		)
Fair value as of March 31, 2020	$	47,885		$	38,637

Schedule of Changes in Nonfinancial Liabilities Related to Warrant Obligations Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs

The following table provides information regarding changes in nonfinancial liabilities related to the Company’s warranty obligations measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the periods indicated.

	Three Months Ended March 31,
	2020			2019
	(In thousands)
Balance at beginning of period	$	19,806		$	11,757
Accruals for warranties issued during period	1,524			858
Changes in estimates	615			341
Settlements	(1,993		)	(1,272		)
Increase due to accretion expense	774			551
Other	(301		)	(170		)
Balance at end of period	$	20,425		$	12,065

Summary of Significant Unobservable Inputs used in the Fair Value Measurement of Liabilities Designated as Level 3

As of March 31, 2020 and December 31, 2019, the significant unobservable inputs used in the fair value measurement of the Company’s liabilities designated as Level 3 are as follows:

			Percent Used (Weighted Average)
Item Measured at Fair Value	Valuation Technique	Description of Significant Unobservable Input	March 31, 2020	December 31, 2019
Warranty obligations for microinverters sold since January 1, 2014	Discounted cash flows	Profit element and risk premium	15%	14%
		Credit-adjusted risk-free rate	16%	16%