Enphase Energy (ENPH) 10-Q 30 Apr 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 23, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	Enphase Energy, Inc.
Entity Central Index Key	0001463101
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Amendment Flag	false
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Current Fiscal Year End	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Common Stock, Shares Outstanding		110,226,728

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 78,087	$ 106,237
Accounts receivable, net	81,715	78,938
Inventory	12,971	16,267
Prepaid expenses and other assets	22,669	20,860
Total current assets	195,442	222,302
Property and equipment, net	20,178	20,998
Operating lease, right of use asset	7,963
Intangible assets, net	34,124	35,306
Goodwill	24,783	24,783
Other assets	36,762	36,548
Total assets	319,252	339,937
Current liabilities:
Accounts payable	52,489	48,794
Accrued liabilities	32,431	29,010
Deferred revenues, current	32,916	33,119
Warranty obligations	7,925	8,083
Debt, current	2,985	28,155
Total current liabilities	128,746	147,161
Long-term liabilities:
Deferred revenues, noncurrent	78,393	76,911
Warranty obligations, noncurrent	23,117	23,211
Other liabilities	9,466	3,250
Debt, noncurrent	65,406	81,628
Total liabilities	305,128	332,161
Commitments and contingent liabilities (Note 9)
Stockholders’ equity:
Preferred stock, $0.00001 par value, 10,000 shares authorized; none issued and outstanding	0	0
Common stock, $0.00001 par value, 150,000 shares and 150,000 shares authorized; and 110,211 shares and 107,035 shares issued and outstanding at March 31, 2019 and December 31, 2018, respectively	1	1
Additional paid-in capital	357,023	353,335
Accumulated deficit	(343,563)	(346,302)
Accumulated other comprehensive income	663	742
Total stockholders’ equity	14,124	7,776
Total liabilities and stockholders’ equity	$ 319,252	$ 339,937

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in usd per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	110,211,000	107,035,000
Common stock, shares outstanding (in shares)	110,211,000	107,035,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Net revenues	$ 100,150	$ 69,972
Cost of revenues	66,811	51,657
Gross profit	33,339	18,315
Operating expenses:
Research and development	8,524	7,620
Sales and marketing	7,433	6,227
General and administrative	9,880	6,943
Restructuring charges	368	0
Total operating expenses	26,205	20,790
Income (loss) from operations	7,134	(2,475)
Other expense, net
Interest expense	(3,540)	(2,292)
Other expense	(481)	(126)
Total other expense, net	(4,021)	(2,418)
Income (loss) before income taxes	3,113	(4,893)
Provision for income taxes	(348)	(235)
Net income (loss)	$ 2,765	$ (5,128)
Net income (loss) per share:
Basic (in USD per share)	$ 0.03	$ (0.06)
Diluted (in USD per share)	$ 0.02	$ (0.06)
Shares used in per share calculation:
Basic (in shares)	108,195	91,422
Diluted (in shares)	115,863	91,422

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 2,765	$ (5,128)
Other comprehensive (loss) income:
Foreign currency translation adjustments	(79)	288
Comprehensive income (loss)	$ 2,686	$ (4,840)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDER'S EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock and Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance, beginning of period at Dec. 31, 2017		$ 287,257	$ (295,727)	$ (656)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under equity incentive and stock purchase plans, net		269
Issuance of common stock, net		19,923
Stock-based compensation expense and other		1,571
Net income (loss)	$ (5,128)		(5,128)
Foreign currency translation adjustments	288			288
Balance, end of period at Mar. 31, 2018	(31,151)	309,020	(339,803)	(368)
Balance, beginning of period at Dec. 31, 2018	7,776	353,336	(346,302)	742
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued under equity incentive and stock purchase plans, net		309
Issuance of common stock, net		0
Stock-based compensation expense and other		3,353
Net income (loss)	2,765		2,765
Foreign currency translation adjustments	(79)			(79)
Balance, end of period at Mar. 31, 2019	$ 14,124	$ 357,024	$ (343,563)	$ 663

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ 2,765	$ (5,128)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	3,572	2,276
Provision for doubtful accounts	0	600
Amortization of debt issuance costs	1,490	537
Financing fees on extinguishment of debt	2,152	0
Stock-based compensation	3,290	1,571
Changes in operating assets and liabilities:
Accounts receivable	(3,266)	9,125
Inventory	3,296	7,457
Prepaid expenses and other assets	(2,413)	(1,039)
Accounts payable, accrued and other liabilities	4,851	(11,667)
Warranty obligations	(252)	809
Deferred revenues	1,578	(1,180)
Net cash provided by operating activities	17,063	3,361
Cash flows from investing activities:
Purchases of property and equipment	(658)	(1,043)
Net cash used in investing activities	(658)	(1,043)
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs	0	19,923
Proceeds from debt, net of issuance costs	0	2,309
Principal payments and financing fees on debt	(44,731)	(771)
Proceeds from issuance of common stock under employee stock plans, net	309	269
Net cash provided by (used in) financing activities	(44,422)	21,730
Effect of exchange rate changes on cash	(133)	63
Cash and cash equivalents—Beginning of period	(28,150)	24,111
Cash and cash equivalents—Beginning of period	106,237	29,144
Cash and cash equivalents—End of period	78,087	53,255
Supplemental disclosures of non-cash investing and financing activities:
Purchases of fixed assets included in accounts payable	458	$ 117
Operating lease, right of use asset	$ 8,392

DESCRIPTION OF BUSINESS AND BAS

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Description of Business Enphase Energy, Inc. (the “Company”) is a global energy technology company . The Company delivers smart, easy-to-use solutions that connect solar generation, storage and management on one intelligent platform. The Company revolutionized solar with its microinverter technology and produces a fully-integrated solar plus storage solution. Basis of Presentation and Consolidation The accompanying condensed consolidated financial statements are presented in accordance with accounting principles generally accepted in the United States (“U.S”), or GAAP. The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The year-end condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the U.S. The Company filed audited consolidated financial statements, which included all information and notes necessary for such a complete presentation in conjunction with its 2018 Annual Report on Form 10-K. Unaudited Interim Financial Information These accompanying unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”) for interim financial reporting. In the opinion of management, these unaudited condensed consolidated financial statements reflect all adjustments, consisting of normal recurring items, considered necessary to present fairly the Company’s financial condition, results of operations, comprehensive income (loss) and cash flows for the interim periods indicated. The results of operations for the three months ended March 31, 2019 are not necessarily indicative of the operating results for the full year. Use of Estimates In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, “Leases (Topic 842).” ASU 2016-02 requires an entity to recognize a right-of-use asset and lease liability for all leases with terms of more than 12 months. The guidance requires lessees to recognize all leases, with certain exceptions, on their balance sheets, whether operating or financing, while continuing to recognize the expenses on their income statements in a manner similar to current practice. The guidance states that a lessee must recognize a lease liability for the obligation to make lease payments and a right-to-use asset for the right to use the underlying asset for the lease term. On January 1, 2019, the Company adopted ASU 2016-02 using the modified retrospective transition option of applying the new standard at the adoption date for all leases with terms greater than 12 months. The Company elected certain practical expedients upon adoption and as such did not reassess the following: 1) whether any expired or existing contracts are or contain leases; 2) lease classification for any expired or existing leases; 3) initial direct costs for any expired or existing leases; 4) whether existing or expired land easements are or contain leases; and 5) regarding the lease term, from a hindsight perspective, whether or not the Company is reasonably certain to exercise the lease options. However, the Company will evaluate new or modified land easements under the new guidance after the commencement date. The Company also elected the practical expedient to not separate lease and non-lease components. The adoption of ASU 2016-02 on January 1, 2019 resulted in an increase in operating leases, right of use asset of $8.4 million , an increase in other liabilities of $6.8 million , an increase in accrued liabilities and other of $1.5 million and a decrease in other assets of $0.1 million on the Company’s consolidated balance sheets with no impact on the Company’s consolidated statements of operations.

REVENUE RECOGNITION

REVENUE RECOGNITION	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION	REVENUE RECOGNITION Disaggregated Revenue The Company has one business activity, which is the design, manufacture and sale of solutions for the solar photovoltaic (“PV”) industry. The following table provides information about disaggregated revenue by primary geographical market and timing of revenue recognition for the Company’s single product line: Three Months Ended 2019 2018 (In thousands) Primary geographical markets: United States $ 77,686 $ 43,130 International 22,464 26,842 Total $ 100,150 $ 69,972 Timing of revenue recognition: Products delivered at a point in time $ 90,400 $ 59,371 Products and services delivered over time 9,750 10,601 Total $ 100,150 $ 69,972 Contract Balances Receivables, and contract assets and contract liabilities from contracts with customers are as follows: March 31, December 31, (In thousands) Receivables $ 81,715 $ 78,938 Short-term contract assets (Prepaid expenses and other assets) 13,595 13,516 Long-term contract assets (Other assets) 34,683 34,148 Short-term contract liabilities (Deferred revenues) 32,916 33,119 Long-term contract liabilities (Deferred revenues) 78,393 76,911 The Company receives payments from customers based upon contractual billing schedules. Accounts receivable are recorded when the right to consideration becomes unconditional. Contract assets include deferred product costs and commissions associated with the deferred revenue and will be amortized along with the associated revenue. The Company had no asset impairment charges related to contract assets in the three months ended March 31, 2019 . Contract liabilities are recorded as deferred revenue on the accompanying condensed consolidated balance sheets and include payments received in advance of performance obligations under the contract and are realized when the associated revenue is recognized under the contract. Significant changes in the balances of contract assets (prepaid expenses and other assets) and contract liabilities (deferred revenues) during the period are as follows (in thousands): Contract Assets Balance on December 31, 2018 $ 47,664 Amount recognized (3,594 ) Increase 4,208 Balance as of March 31, 2019 $ 48,278 Contract Liabilities Balance on December 31, 2018 $ 110,030 Revenue recognized (9,750 ) Increase due to billings 11,029 Balance as of March 31, 2019 $ 111,309 Remaining Performance Obligations The following table includes estimated revenue expected to be recognized in future periods related to performance obligations that are unsatisfied or partially unsatisfied at the end of the reporting period. March 31, (In thousands) Fiscal year: 2019 (remaining nine months) $ 26,092 2020 27,797 2021 21,626 2022 16,594 2023 10,801 Thereafter 8,399 Total $ 111,309

OTHER FINANCIAL INFORMATION

OTHER FINANCIAL INFORMATION	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Other Financial Information	OTHER FINANCIAL INFORMATION Accounts Receivable, Net Accounts receivable, net consist of the following: March 31, December 31, (In thousands) Accounts receivable $ 83,855 $ 81,076 Allowance for doubtful accounts (2,140 ) (2,138 ) Accounts receivable, net $ 81,715 $ 78,938 Inventory Inventory consist of the following: March 31, December 31, (In thousands) Raw materials $ 950 $ 970 Finished goods 12,021 15,297 Total inventory $ 12,971 $ 16,267 Accrued Liabilities Accrued liabilities consist of the following: March 31, December 31, (In thousands) Salaries, commissions, incentive compensation and benefits $ 6,442 $ 4,107 Customer rebates and sales incentives 8,769 8,527 Freight 7,599 7,286 Other 9,621 9,090 Total accrued liabilities $ 32,431 $ 29,010

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS The following table presents the details of the Company’s goodwill and purchased intangible assets: March 31, 2019 December 31, 2018 Gross Accumulated Amortization Net Gross Additions Accumulated Amortization Net (In thousands) Goodwill $ 24,783 $ — $ 24,783 $ 3,664 $ 21,119 $ — $ 24,783 Intangible assets: Other indefinite-lived intangibles $ 286 $ — $ 286 $ 286 $ — $ — $ 286 Intangible assets with finite lives: Patents and licensed technology 1,665 (1,665 ) — 1,665 — (1,665 ) — Developed technology 13,100 (1,455 ) 11,645 — 13,100 (909 ) 12,191 Customer relationships 23,100 (907 ) 22,193 — 23,100 (271 ) 22,829 Total purchased intangible assets $ 38,151 $ (4,027 ) $ 34,124 $ 1,951 $ 36,200 $ (2,845 ) $ 35,306 In August 2018, the Company acquired certain finite-lived intangible assets in its acquisition of SunPower Corporation ’s (“ SunPower ”) microinverter business pursuant to an Asset Purchase Agreement (“APA”), primarily developed technology and customer relationships. See Note 20. “Acquisition,” of the notes to consolidated financial statements included in Item 8 of the Company’s 2018 Form 10‑K filed with the SEC on March 15, 2019 for additional information related to this acquisition. Amortization expense related to finite-lived intangible assets are as follows: Three Months Ended 2019 2018 (In thousands) Developed technology, and patents and licensed technology $ 546 $ 76 Customer relationships 636 — Total amortization expense $ 1,182 $ 76 Amortization of developed technology, patents and licensed technology is primarily recorded to sales and marketing expense. The developed technology acquired from the Company’s acquisition of SunPower’s microinverter business is embedded in the microinverters that SunPower sells to its customers. The Company does not actively use the developed technology acquired from SunPower and holds the developed technology to prevent others from using it. Accordingly, the Company accounts for the developed technology as a defensive intangible asset and amortizes the associated value over a period of six years from the date of acquisition. The master service agreement (“MSA”) negotiated with SunPower in August 2018 provides the Company with the exclusive right to supply SunPower with module level power electronics for a period of five years , with options for renewals. The exclusivity arrangement extends throughout the term of the MSA, which comprises all of the expected cash flows from the customer relationship intangible asset, and was a condition to, and was an essential part of the acquisition of the SunPower’s microinverter business by the Company. As the fair value ascribed to the customer relationship intangible asset represents payments to a customer, the Company amortizes the value of the customer relationship intangible asset as a reduction to revenue using a pattern of economic benefit method over a useful life of nine years

WARRANTY OBLIGATIONS

WARRANTY OBLIGATIONS	3 Months Ended
	Mar. 31, 2019
Product Warranties Disclosures [Abstract]
WARRANTY OBLIGATIONS	WARRANTY OBLIGATIONS The Company’s warranty activities were as follows: Three Months Ended 2019 2018 (In thousands) Warranty obligations, beginning of period $ 31,294 $ 29,816 Accruals for warranties issued during period 858 758 Changes in estimates 804 1,450 Settlements (2,296 ) (1,676 ) Increase due to accretion expense 551 419 Other (169 ) (142 ) Warranty obligations, end of period 31,042 30,625 Less current portion (7,925 ) (7,699 ) Noncurrent $ 23,117 $ 22,926

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The accounting guidance defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance. The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. An asset’s or liability’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value: • Level 1—Valuations based on quoted prices in active markets for identical assets or liabilities that the Company is able to access. Since valuations are based on quoted prices that are readily and regularly available in an active market, valuation of such assets or liabilities do not entail a significant degree of judgment. • Level 2—Valuations based on one or more quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. • Level 3—Valuations based on inputs that are unobservable and significant to the overall fair value measurement. The following table presents the Company’s liabilities that were measured at fair value on a recurring basis and its categorization within the fair value hierarchy: Fair Value March 31, December 31, (In thousands) Warranty obligations Current $ 4,237 $ 4,288 Non-current 7,828 7,469 Total warranty obligations Level 3 $ 12,065 $ 11,757 Fair Value Option for Warranty Obligations Related to Microinverters Sold Since January 1, 2014 The Company estimates the fair value of warranty obligations by calculating the warranty obligations in the same manner as for sales prior to January 1, 2014 and applying an expected present value technique to that result. The expected present value technique, an income approach, converts future amounts into a single current discounted amount. In addition to the key estimates of failure rates, claim rates and replacement costs, the Company used certain Level 3 inputs which are unobservable and significant to the overall fair value measurement. Such additional assumptions included a discount rate based on the Company’s credit-adjusted risk-free rate and compensation comprised of a profit element and risk premium required of a market participant to assume the obligation. 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 2019 2018 (In thousands) Balance at beginning of period $ 11,757 $ 9,791 Accruals for warranties issued during period 858 758 Changes in estimates 341 1,785 Settlements (1,272 ) (891 ) Increase due to accretion expense 551 419 Other (170 ) (142 ) Balance at end of period $ 12,065 $ 11,720 Quantitative and Qualitative Information about Level 3 Fair Value Measurements As of March 31, 2019 and December 31, 2018 , 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, December 31, Warranty obligations for microinverters sold since January 1, 2014 Discounted cash flows Profit element and risk premium 14% 16% Credit-adjusted risk-free rate 18% 19% Sensitivity of Level 3 Inputs - Warranty Obligations Each of the significant unobservable inputs is independent of the other. The profit element and risk premium are estimated based on requirements of a third-party participant willing to assume the Company’s warranty obligations. The credit‑adjusted risk‑free rate (“discount rate”) is determined by reference to the Company’s own credit standing at the fair value measurement date. Increasing the profit element and risk premium input by 100 basis points would result in a $0.1 million increase to the liability. Decreasing the profit element and risk premium by 100 basis points would result in a $0.1 million reduction of the liability. Increasing the discount rate by 100 basis points would result in a $0.5 million reduction of the liability. Decreasing the discount rate by 100 basis points would result in a $0.5 million increase to

RESTRUCTURING

RESTRUCTURING	3 Months Ended
	Mar. 31, 2019
Restructuring and Related Activities [Abstract]
RESTRUCTURING	RESTRUCTURING Restructuring expense consist of the following: Three Months Ended 2019 2018 (In thousands) Redundancy and employee severance and benefit arrangements $ 468 $ — Lease loss reserves (100 ) — Total restructuring charges $ 368 $ — In the third quarter of 2018, the Company began implementing restructuring actions (the “2018 Plan”) to lower its operating expenses. The restructuring actions include reorganization of the Company’s global workforce, elimination of certain non-core projects and consolidation of facilities. The Company expects to complete this restructuring in 2019. The following table provides information regarding changes in the Company’s 2018 Plan accrued restructuring balance for the periods indicated: Redundancy and Employee Severance and Benefits Lease Loss Reserves and Contractual Obligations Total (In thousands) Balance as of December 31, 2018 $ 904 $ 288 $ 1,192 Charges 468 — 468 Cash payments (752 ) — (752 ) Non-cash settlement and other (55 ) (288 ) (343 ) Balance as of March 31, 2019 $ 565 $ — $ 565 In the third quarter of 2016, the Company began implementing restructuring actions (the “2016 Plan”) to lower its operating expenses. The restructuring actions have included reductions in the Company’s global workforce, the elimination of certain non-core projects, consolidation of office space at the Company’s corporate headquarters and the engagement of management consultants to assist the Company in making organizational and structural changes to improve operational efficiencies and reduce expenses. The Company substantially completed its restructuring activities under the 2016 Plan in 2017. The following table provides information regarding changes in the Company’s 2016 Plan accrued restructuring balance for the periods indicated: Lease Loss Reserves and Contractual Obligations (In thousands) Balance as of December 31, 2018 $ 1,591 Other (1) (1,591 ) Balance as of March 31, 2019 $ — (1)

DEBT

DEBT	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
DEBT	DEBT Long-term debt was comprised of the following: March 31, December 31, (In thousands) Convertible notes due 2023 $ 65,000 $ 65,000 Less unamortized issuance costs (2,232 ) (2,361 ) Carrying amount of convertible notes due 2023 62,768 62,639 Term loan — 41,524 Less unamortized discount and issuance costs — (1,059 ) Carrying amount of term loan — 40,465 Sale of long-term financing receivable recorded as debt 5,623 6,679 Less value of future purchase option — — Carrying amount of sale of long-term financing receivable recorded as debt 5,623 6,679 Total carrying amount of debt 68,391 109,783 Less current portion term loan — (25,417 ) Less current portion of long-term financing receivable recorded as debt (2,985 ) (2,738 ) Long-term debt $ 65,406 $ 81,628 In July 2016 , the Company entered into a Loan and Security Agreement (the “Original Term Loan Agreement”) with lenders that are affiliates of Tennenbaum Capital Partners, LLC. In February 2017 , the Company entered into an Amended and Restated Loan and Security Agreement (the “Loan Agreement”) that amended and restated the Original Term Loan Agreement. The Loan Agreement provided for a $25.0 million secured term loan to the Company (the “New Term Loan”), which is in addition to the $25.0 million secured term loan borrowed by the Company under the Original Term Loan Agreement (together with the “New Term Loan” the “Term Loans”). On January 28, 2019, the Company repaid in full the remaining principal amount of the Term Loans of approximately $39.5 million plus accrued interest and fees

COMMITMENTS AND CONTINGENCt LIA

COMMITMENTS AND CONTINGENCt LIABILITIES	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENT LIABILITIES	COMMITMENTS AND CONTINGENT LIABILITIES Operating Leases The Company leases office facilities under noncancelable operating leases that expire on various dates through 2028, some of which may include options to extend the leases for up to 12 years . The terms of the lease agreements generally provide for rental payments on a graduated basis, and certain leases require the Company to pay its portion of executory costs such as taxes, insurance, and operating expenses. The Company recognizes rent expense on a straight-line basis over the lease term. The components of lease expense are presented as follows: Three Months Ended (In thousands) Operating lease cost $ 499 The components of lease liabilities are presented as follows: March 31, (In thousands) Lease liabilities, current (Accrued liabilities) $ 2,181 Lease liabilities, non-current (Other liabilities) 7,837 Total lease liabilities $ 10,018 Supplemental lease information Weighted average remaining lease term 4.4 years Weighted average discount rate 9.2% Other information related to operating leases, are as follows: Three Months Ended (In thousands) Cash paid for amounts included in the measurement of lease liabilities $ 737 Maturities of lease liabilities as of March 31, 2019 are as follows: Lease Amounts (In thousands) Year: 2019 (remaining nine months) $ 2,248 2020 3,071 2021 3,155 2022 1,717 2023 893 Thereafter 1,227 Total 12,311 Less imputed lease interest (2,293 ) Total lease liabilities $ 10,018

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION Stock-based compensation expense for all stock-based awards expected to vest is measured at fair value on the date of grant and recognized ratably over the requisite service period. The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations for the periods presented : Three Months Ended 2019 2018 (In thousands) Cost of revenues $ 231 $ 198 Research and development 716 618 Sales and marketing 999 361 General and administrative 1,288 394 Restructuring 55 — Total $ 3,289 $ 1,571 The following table summarizes the various types of stock-based compensation expense for the periods presented: Three Months Ended 2019 2018 (In thousands) Stock options, RSUs, and PSUs $ 3,222 $ 1,317 Employee stock purchase plan 67 254 Total $ 3,289 $ 1,571 As of March 31, 2019 , there was approximately $30.3 million of total unrecognized stock-based compensation expense related to unvested equity awards expected to be recognized over a weighted-average period of 2.1 years . No income tax benefit has been recognized relating to stock-based compensation expense and no tax benefits have been realized from exercised stock options for the three months ended March 31, 2019 Stock Options The fair value of each option granted was estimated on the date of grant using the Black-Scholes option-pricing model with the following assumptions: • Expected term— The expected term of the option awards represents the period of time between the grant date of the option awards and the date the option awards are either exercised, converted or canceled, including an estimate for those option awards still outstanding. The Company used the simplified method, as permitted by the SEC for companies with a limited history of stock option exercise activity, to determine the expected term for its option grants. • Expected volatility— The expected volatility was calculated based on the Company’s historical stock prices, supplemented as necessary with historical volatility of the common stock of several peer companies with characteristics similar to those of the Company. • Risk-free interest rate— The risk-free interest rate was based on the U.S. Treasury yield curve in effect at the time of grant and with a maturity that approximated the Company’s expected term. • Dividend yield— The dividend yield was based on the Company’s dividend history and the anticipated dividend payout over its expected term. The following table presents the weighted-average grant date fair value of options granted for the periods presented and the assumptions used to estimate those values using a Black-Scholes option pricing model: Three Months Ended 2019 2018 Weighted average grant date fair value ** $ 1.83 Expected term (in years) ** 4.2 Expected volatility ** 86.4 % Annual risk-free rate of return ** 2.4 % Dividend yield ** — % ** No stock options were granted during the period. Restricted Stock Units The fair value of the Company’s restricted stock units (“RSU”) awards granted is based upon the closing price of the Company’s stock price on the date of grant. Performance Stock Units Stock Options The following is a summary of stock option activity: Number of Weighted- Weighted- Aggregate (1) (In thousands) (Years) (In thousands) Outstanding at December 31, 2018 6,772 $ 1.76 Granted — — Exercised (1,573 ) 1.06 $ 10,715 Canceled (55 ) 5.55 Outstanding at March 31, 2019 5,144 1.94 4.8 $ 37,671 Vested and expected to vest at March 31, 2019 5,144 1.94 4.8 $ 37,671 Exercisable at March 31, 2019 3,318 2.20 4.6 $ 23,471 (1) The intrinsic value of options exercised is based upon the value of the Company’s stock at exercise. The intrinsic value of options outstanding, vested and expected to vest, and exercisable as of March 31, 2019 is based on the closing price of the Company’s stock fair value on March 31, 2019 or the earlier of the last trading day prior to March 31, 2019 , if March 31, 2019 is a non-trading day. The Company’s stock fair value used in this computation was $9.23 March 31, 2019 : Options Outstanding Options Exercisable Range of Exercise Prices Number of Weighted- Weighted- Number of Weighted- (In thousands) (Years) (In thousands) $0.27 —– $1.14 1,061 5.6 $ 0.83 703 $ 0.79 $1.29 —– $1.29 1,000 5.5 1.29 375 1.29 $1.31 —– $1.31 1,752 5.0 1.31 1,230 1.31 $1.37 —– $6.98 1,034 3.9 2.90 713 3.03 $7.01 —– $12.57 297 2.2 8.40 297 8.40 Total 5,144 4.8 1.94 3,318 2.20 The following is a summary of RSU activity: Number of Weighted- Weighted- Aggregate (1) (In thousands) (Years) (In thousands) Outstanding at December 31, 2018 4,352 $ 3.52 Granted 1,114 8.12 Vested (716 ) 3.70 $ 6,255 Canceled (216 ) 2.02 Outstanding at March 31, 2019 4,534 4.70 1.5 $ 41,845 Expected to vest at March 31, 2019 4,532 4.70 1.5 $ 41,835 (1) The intrinsic value of RSUs vested is based upon the value of the Company’s stock when vested. The intrinsic value of RSUs outstanding and expected to vest as of March 31, 2019 is based on the closing price of the Company’s stock on March 31, 2019 or the earlier of the last trading day prior to March 31, 2019 , if March 31, 2019 is a non-trading day. The Company’s stock fair value used in this computation was $9.23 The following is a summary of PSU activity: Number of Weighted- Weighted- Aggregate (1) (In thousands) (Years) (In thousands) Outstanding at December 31, 2018 1,330 $ 4.66 Granted 1,046 9.40 Vested (1,026 ) 4.63 $ 9,925 Canceled (337 ) 4.78 Outstanding at March 31, 2019 1,013 8.64 1.0 $ 9,349 Expected to vest at March 31, 2019 1,013 8.64 1.0 $ 9,349 (1) The intrinsic value of PSUs vested is based upon the value of the Company’s stock when vested. The intrinsic value of PSUs outstanding and expected to vest as of March 31, 2019 is based on the closing price of the Company’s stock on March 31, 2019 or the earlier of the last trading day prior to March 31, 2019 , if March 31, 2019 is a non-trading day. The Company’s stock fair value used in this computation was $9.23

INCOME TAXES

INCOME TAXES	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company used the discrete tax approach in calculating the tax expense for the three months ended March 31, 2019 and 2018

NET INCOME (LOSS) PER SHARE

NET INCOME (LOSS) PER SHARE	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
NET INCOME (LOSS) PER SHARE	NET INCOME (LOSS) PER SHARE Basic net income (loss) per share is computed by dividing net income (loss) by the weighted average number of shares of common stock outstanding during the period. Diluted net income (loss) per share is computed in a similar manner, but it also includes the effect of potential common shares outstanding during the period, when dilutive. Potential common shares include stock options, RSUs, PSUs, shares to be purchased under the Company’s employee stock purchase program (“ESPP”), and the convertible notes. The dilutive effect of potentially dilutive common shares is reflected in diluted earnings per share by application of the treasury stock method. To the extent these potential common shares are antidilutive, they are excluded from the calculation of diluted net income (loss) per share. The following table presents the computation of basic and diluted net income (loss) per share for the periods presented: Three Months Ended 2019 2018 (In thousands, except per share data) Numerator: Net income (loss) $ 2,765 $ (5,128 ) Denominator: Weighted average common shares outstanding 108,195 91,422 Effect of dilutive securities Employee stock-based awards 7,668 — Weighted average common shares outstanding for diluted calculation 115,863 91,422 Net income (loss) per share, basic $ 0.03 $ (0.06 ) Net income (loss) per share, diluted $ 0.02 $ (0.06 ) As the Company incurred a net loss for the three months ended March 31, 2018 , potential dilutive securities from employee stock options, RSUs, PSUs, and shares to be purchased under the Company’s ESPP have been excluded from the diluted net loss per share computation because the effect of including such shares would have been antidilutive. The following outstanding shares of common stock equivalents were excluded from the calculation of the diluted net income (loss) per share attributable to common stockholders because their effect would have been antidilutive: Three Months Ended 2019 2018 (In thousands) Employee stock options 112 8,418 RSUs and PSUs 91 3,659 Convertible notes 11,701 — Total 11,904 12,077

RELATED PARTY

RELATED PARTY	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related Party	RELATED PARTY The Company sells products to SunPower , which as of March 31, 2019 held 7.5 million shares of the Company’s common stock, under the August 2018 MSA. Revenue recognized under the MSA for the three months ended March 31, 2019 was $4.5 million , net of amortization of the customer relationship intangible asset (see Note 4 . “ Goodwill and Intangible Assets ”). At March 31, 2019 and December 31, 2018 , the Company had accounts receivable of $5.2 million and $10.3 million , respectively, from SunPower

DESCRIPTION OF BUSINESS AND B_2

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Policies)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Consolidation	Basis of Presentation and Consolidation The accompanying condensed consolidated financial statements are presented in accordance with accounting principles generally accepted in the United States (“U.S”), or GAAP. The condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The year-end condensed consolidated balance sheet data was derived from audited financial statements but does not include all disclosures required by accounting principles generally accepted in the U.S. The Company filed audited consolidated financial statements, which included all information and notes necessary for such a complete presentation in conjunction with its 2018
Use of Estimates	Use of EstimatesThe preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. Significant estimates and assumptions reflected in the financial statements include revenue recognition, inventory valuation and accrued warranty obligations. These estimates are based on information available as of the date of the financial statements; therefore, actual results could differ materially from management’s estimates using different assumptions or under different conditions.
New Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, “Leases (Topic 842).” ASU 2016-02 requires an entity to recognize a right-of-use asset and lease liability for all leases with terms of more than 12 months. The guidance requires lessees to recognize all leases, with certain exceptions, on their balance sheets, whether operating or financing, while continuing to recognize the expenses on their income statements in a manner similar to current practice. The guidance states that a lessee must recognize a lease liability for the obligation to make lease payments and a right-to-use asset for the right to use the underlying asset for the lease term. On January 1, 2019, the Company adopted ASU 2016-02 using the modified retrospective transition option of applying the new standard at the adoption date for all leases with terms greater than 12 months. The Company elected certain practical expedients upon adoption and as such did not reassess the following: 1) whether any expired or existing contracts are or contain leases; 2) lease classification for any expired or existing leases; 3) initial direct costs for any expired or existing leases; 4) whether existing or expired land easements are or contain leases; and 5) regarding the lease term, from a hindsight perspective, whether or not the Company is reasonably certain to exercise the lease options. However, the Company will evaluate new or modified land easements under the new guidance after the commencement date. The Company also elected the practical expedient to not separate lease and non-lease components. The adoption of ASU 2016-02 on January 1, 2019 resulted in an increase in operating leases, right of use asset of $8.4 million , an increase in other liabilities of $6.8 million , an increase in accrued liabilities and other of $1.5 million and a decrease in other assets of $0.1 million on the Company’s consolidated balance sheets with no impact on the Company’s consolidated statements of operations.
Fair Value Measurement	The accounting guidance defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance. The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. An asset’s or liability’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value: • Level 1—Valuations based on quoted prices in active markets for identical assets or liabilities that the Company is able to access. Since valuations are based on quoted prices that are readily and regularly available in an active market, valuation of such assets or liabilities do not entail a significant degree of judgment. • Level 2—Valuations based on one or more quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly. •
Earnings Per Share	Basic net income (loss) per share is computed by dividing net income (loss) by the weighted average number of shares of common stock outstanding during the period. Diluted net income (loss) per share is computed in a similar manner, but it also includes the effect of potential common shares outstanding during the period, when dilutive. Potential common shares include stock options, RSUs, PSUs, shares to be purchased under the Company’s employee stock purchase program (“ESPP”), and the convertible notes. The dilutive effect of potentially dilutive common shares is reflected in diluted earnings per share by application of the treasury stock method. To the extent these potential common shares are antidilutive, they are excluded from the calculation of diluted net income (loss)

REVENUE RECOGNITION (Tables)

REVENUE RECOGNITION (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Summary of Revenue Disaggregation	The following table provides information about disaggregated revenue by primary geographical market and timing of revenue recognition for the Company’s single product line: Three Months Ended 2019 2018 (In thousands) Primary geographical markets: United States $ 77,686 $ 43,130 International 22,464 26,842 Total $ 100,150 $ 69,972 Timing of revenue recognition: Products delivered at a point in time $ 90,400 $ 59,371 Products and services delivered over time 9,750 10,601 Total $ 100,150 $ 69,972
Summary of Contract Assets and Contract Liabilities, and Changes in Balances from Contracts with Customers	Significant changes in the balances of contract assets (prepaid expenses and other assets) and contract liabilities (deferred revenues) during the period are as follows (in thousands): Contract Assets Balance on December 31, 2018 $ 47,664 Amount recognized (3,594 ) Increase 4,208 Balance as of March 31, 2019 $ 48,278 Contract Liabilities Balance on December 31, 2018 $ 110,030 Revenue recognized (9,750 ) Increase due to billings 11,029 Balance as of March 31, 2019 $ 111,309 March 31, December 31, (In thousands) Receivables $ 81,715 $ 78,938 Short-term contract assets (Prepaid expenses and other assets) 13,595 13,516 Long-term contract assets (Other assets) 34,683 34,148 Short-term contract liabilities (Deferred revenues) 32,916 33,119 Long-term contract liabilities (Deferred revenues) 78,393 76,911
Summary of Estimated Revenue Expected to be Recognized in Future Periods	The following table includes estimated revenue expected to be recognized in future periods related to performance obligations that are unsatisfied or partially unsatisfied at the end of the reporting period. March 31, (In thousands) Fiscal year: 2019 (remaining nine months) $ 26,092 2020 27,797 2021 21,626 2022 16,594 2023 10,801 Thereafter 8,399 Total $ 111,309

OTHER FINANCIAL INFORMATION (Ta

OTHER FINANCIAL INFORMATION (Tables)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Accounts Receivable	Accounts receivable, net consist of the following: March 31, December 31, (In thousands) Accounts receivable $ 83,855 $ 81,076 Allowance for doubtful accounts (2,140 ) (2,138 ) Accounts receivable, net $ 81,715 $ 78,938
Schedule of Inventory	Inventory consist of the following: March 31, December 31, (In thousands) Raw materials $ 950 $ 970 Finished goods 12,021 15,297 Total inventory $ 12,971 $ 16,267
Schedule of Accrued Liabilities	Accrued liabilities consist of the following: March 31, December 31, (In thousands) Salaries, commissions, incentive compensation and benefits $ 6,442 $ 4,107 Customer rebates and sales incentives 8,769 8,527 Freight 7,599 7,286 Other 9,621 9,090 Total accrued liabilities $ 32,431 $ 29,010

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill and Intangible Assets	The following table presents the details of the Company’s goodwill and purchased intangible assets: March 31, 2019 December 31, 2018 Gross Accumulated Amortization Net Gross Additions Accumulated Amortization Net (In thousands) Goodwill $ 24,783 $ — $ 24,783 $ 3,664 $ 21,119 $ — $ 24,783 Intangible assets: Other indefinite-lived intangibles $ 286 $ — $ 286 $ 286 $ — $ — $ 286 Intangible assets with finite lives: Patents and licensed technology 1,665 (1,665 ) — 1,665 — (1,665 ) — Developed technology 13,100 (1,455 ) 11,645 — 13,100 (909 ) 12,191 Customer relationships 23,100 (907 ) 22,193 — 23,100 (271 ) 22,829 Total purchased intangible assets $ 38,151 $ (4,027 ) $ 34,124 $ 1,951 $ 36,200 $ (2,845 ) $ 35,306
Schedule of Amortization Expense	Amortization expense related to finite-lived intangible assets are as follows: Three Months Ended 2019 2018 (In thousands) Developed technology, and patents and licensed technology $ 546 $ 76 Customer relationships 636 — Total amortization expense $ 1,182 $ 76

WARRANTY OBLIGATIONS (Tables)

WARRANTY OBLIGATIONS (Tables)	3 Months Ended
	Mar. 31, 2019
Product Warranties Disclosures [Abstract]
Summary of Warranty Activities	The Company’s warranty activities were as follows: Three Months Ended 2019 2018 (In thousands) Warranty obligations, beginning of period $ 31,294 $ 29,816 Accruals for warranties issued during period 858 758 Changes in estimates 804 1,450 Settlements (2,296 ) (1,676 ) Increase due to accretion expense 551 419 Other (169 ) (142 ) Warranty obligations, end of period 31,042 30,625 Less current portion (7,925 ) (7,699 ) Noncurrent $ 23,117 $ 22,926

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following table presents the Company’s liabilities that were measured at fair value on a recurring basis and its categorization within the fair value hierarchy: Fair Value March 31, December 31, (In thousands) Warranty obligations Current $ 4,237 $ 4,288 Non-current 7,828 7,469 Total warranty obligations Level 3 $ 12,065 $ 11,757
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 2019 2018 (In thousands) Balance at beginning of period $ 11,757 $ 9,791 Accruals for warranties issued during period 858 758 Changes in estimates 341 1,785 Settlements (1,272 ) (891 ) Increase due to accretion expense 551 419 Other (170 ) (142 ) Balance at end of period $ 12,065 $ 11,720
Summary of Significant Unobservable Inputs used in the Fair Value Measurement of Liabilities Designated as Level 3	As of March 31, 2019 and December 31, 2018 , 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, December 31, Warranty obligations for microinverters sold since January 1, 2014 Discounted cash flows Profit element and risk premium 14% 16% Credit-adjusted risk-free rate 18% 19%

RESTRUCTURING (Tables)

RESTRUCTURING (Tables)	3 Months Ended
	Mar. 31, 2019
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	Restructuring expense consist of the following: Three Months Ended 2019 2018 (In thousands) Redundancy and employee severance and benefit arrangements $ 468 $ — Lease loss reserves (100 ) — Total restructuring charges $ 368 $ —
Schedule of Restructuring Reserve by Type of Cost	The following table provides information regarding changes in the Company’s 2018 Plan accrued restructuring balance for the periods indicated: Redundancy and Employee Severance and Benefits Lease Loss Reserves and Contractual Obligations Total (In thousands) Balance as of December 31, 2018 $ 904 $ 288 $ 1,192 Charges 468 — 468 Cash payments (752 ) — (752 ) Non-cash settlement and other (55 ) (288 ) (343 ) Balance as of March 31, 2019 $ 565 $ — $ 565 Lease Loss Reserves and Contractual Obligations (In thousands) Balance as of December 31, 2018 $ 1,591 Other (1) (1,591 ) Balance as of March 31, 2019 $ — (1)

DEBT (Tables)

DEBT (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Debt	Long-term debt was comprised of the following: March 31, December 31, (In thousands) Convertible notes due 2023 $ 65,000 $ 65,000 Less unamortized issuance costs (2,232 ) (2,361 ) Carrying amount of convertible notes due 2023 62,768 62,639 Term loan — 41,524 Less unamortized discount and issuance costs — (1,059 ) Carrying amount of term loan — 40,465 Sale of long-term financing receivable recorded as debt 5,623 6,679 Less value of future purchase option — — Carrying amount of sale of long-term financing receivable recorded as debt 5,623 6,679 Total carrying amount of debt 68,391 109,783 Less current portion term loan — (25,417 ) Less current portion of long-term financing receivable recorded as debt (2,985 ) (2,738 ) Long-term debt $ 65,406 $ 81,628

COMMITMENTS AND CONTINGENCt L_2

COMMITMENTS AND CONTINGENCt LIABILITIES (Tables)	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Components of Lease	The components of lease expense are presented as follows: Three Months Ended (In thousands) Operating lease cost $ 499 The components of lease liabilities are presented as follows: March 31, (In thousands) Lease liabilities, current (Accrued liabilities) $ 2,181 Lease liabilities, non-current (Other liabilities) 7,837 Total lease liabilities $ 10,018 Supplemental lease information Weighted average remaining lease term 4.4 years Weighted average discount rate 9.2% Other information related to operating leases, are as follows: Three Months Ended (In thousands) Cash paid for amounts included in the measurement of lease liabilities $ 737
Schedule of Future Minimum Rental Payments for Operating Leases	Maturities of lease liabilities as of March 31, 2019 are as follows: Lease Amounts (In thousands) Year: 2019 (remaining nine months) $ 2,248 2020 3,071 2021 3,155 2022 1,717 2023 893 Thereafter 1,227 Total 12,311 Less imputed lease interest (2,293 ) Total lease liabilities $ 10,018

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of the Components of Total Stock-Based Compensation Expense	The following table summarizes the components of total stock-based compensation expense included in the condensed consolidated statements of operations for the periods presented : Three Months Ended 2019 2018 (In thousands) Cost of revenues $ 231 $ 198 Research and development 716 618 Sales and marketing 999 361 General and administrative 1,288 394 Restructuring 55 — Total $ 3,289 $ 1,571
Summary of Stock-Based Compensation Associated with Each Type of Award	The following table summarizes the various types of stock-based compensation expense for the periods presented: Three Months Ended 2019 2018 (In thousands) Stock options, RSUs, and PSUs $ 3,222 $ 1,317 Employee stock purchase plan 67 254 Total $ 3,289 $ 1,571
Summary of the Weighted-Average Grant Date Fair Value of Options Granted	The following table presents the weighted-average grant date fair value of options granted for the periods presented and the assumptions used to estimate those values using a Black-Scholes option pricing model: Three Months Ended 2019 2018 Weighted average grant date fair value ** $ 1.83 Expected term (in years) ** 4.2 Expected volatility ** 86.4 % Annual risk-free rate of return ** 2.4 % Dividend yield ** — % **
Summary of Stock Option Activity	The following is a summary of stock option activity: Number of Weighted- Weighted- Aggregate (1) (In thousands) (Years) (In thousands) Outstanding at December 31, 2018 6,772 $ 1.76 Granted — — Exercised (1,573 ) 1.06 $ 10,715 Canceled (55 ) 5.55 Outstanding at March 31, 2019 5,144 1.94 4.8 $ 37,671 Vested and expected to vest at March 31, 2019 5,144 1.94 4.8 $ 37,671 Exercisable at March 31, 2019 3,318 2.20 4.6 $ 23,471 (1) The intrinsic value of options exercised is based upon the value of the Company’s stock at exercise. The intrinsic value of options outstanding, vested and expected to vest, and exercisable as of March 31, 2019 is based on the closing price of the Company’s stock fair value on March 31, 2019 or the earlier of the last trading day prior to March 31, 2019 , if March 31, 2019 is a non-trading day. The Company’s stock fair value used in this computation was $9.23
Summary of Stock Option Outstanding	The following table summarizes information about stock options outstanding at March 31, 2019 : Options Outstanding Options Exercisable Range of Exercise Prices Number of Weighted- Weighted- Number of Weighted- (In thousands) (Years) (In thousands) $0.27 —– $1.14 1,061 5.6 $ 0.83 703 $ 0.79 $1.29 —– $1.29 1,000 5.5 1.29 375 1.29 $1.31 —– $1.31 1,752 5.0 1.31 1,230 1.31 $1.37 —– $6.98 1,034 3.9 2.90 713 3.03 $7.01 —– $12.57 297 2.2 8.40 297 8.40 Total 5,144 4.8 1.94 3,318 2.20
Summary of Restricted Stock Unit Activity	The following is a summary of RSU activity: Number of Weighted- Weighted- Aggregate (1) (In thousands) (Years) (In thousands) Outstanding at December 31, 2018 4,352 $ 3.52 Granted 1,114 8.12 Vested (716 ) 3.70 $ 6,255 Canceled (216 ) 2.02 Outstanding at March 31, 2019 4,534 4.70 1.5 $ 41,845 Expected to vest at March 31, 2019 4,532 4.70 1.5 $ 41,835 (1) The intrinsic value of RSUs vested is based upon the value of the Company’s stock when vested. The intrinsic value of RSUs outstanding and expected to vest as of March 31, 2019 is based on the closing price of the Company’s stock on March 31, 2019 or the earlier of the last trading day prior to March 31, 2019 , if March 31, 2019 is a non-trading day. The Company’s stock fair value used in this computation was $9.23
Share-based Compensation, Performance Shares Award Outstanding Activity	The following is a summary of PSU activity: Number of Weighted- Weighted- Aggregate (1) (In thousands) (Years) (In thousands) Outstanding at December 31, 2018 1,330 $ 4.66 Granted 1,046 9.40 Vested (1,026 ) 4.63 $ 9,925 Canceled (337 ) 4.78 Outstanding at March 31, 2019 1,013 8.64 1.0 $ 9,349 Expected to vest at March 31, 2019 1,013 8.64 1.0 $ 9,349 (1) The intrinsic value of PSUs vested is based upon the value of the Company’s stock when vested. The intrinsic value of PSUs outstanding and expected to vest as of March 31, 2019 is based on the closing price of the Company’s stock on March 31, 2019 or the earlier of the last trading day prior to March 31, 2019 , if March 31, 2019 is a non-trading day. The Company’s stock fair value used in this computation was $9.23

NET INCOME (LOSS) PER SHARE (Ta

NET INCOME (LOSS) PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss Per Share	The following table presents the computation of basic and diluted net income (loss) per share for the periods presented: Three Months Ended 2019 2018 (In thousands, except per share data) Numerator: Net income (loss) $ 2,765 $ (5,128 ) Denominator: Weighted average common shares outstanding 108,195 91,422 Effect of dilutive securities Employee stock-based awards 7,668 — Weighted average common shares outstanding for diluted calculation 115,863 91,422 Net income (loss) per share, basic $ 0.03 $ (0.06 ) Net income (loss) per share, diluted $ 0.02 $ (0.06 )
Schedule of Potentially Dilutive Securities Excluded from the Computation of Diluted Net Loss Per Share	The following outstanding shares of common stock equivalents were excluded from the calculation of the diluted net income (loss) per share attributable to common stockholders because their effect would have been antidilutive: Three Months Ended 2019 2018 (In thousands) Employee stock options 112 8,418 RSUs and PSUs 91 3,659 Convertible notes 11,701 — Total 11,904 12,077

DESCRIPTION OF BUSINESS AND B_3

DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION - Impact of Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right of use asset	$ 7,963
Other liabilities	9,466		$ 3,250
Accrued liabilities	32,431		29,010
Other assets	$ 36,762		$ 36,548
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, right of use asset		$ 8,400
Other liabilities		6,800
Accrued liabilities		1,500
Other assets		$ (100)

REVENUE RECOGNITION - Narrative

REVENUE RECOGNITION - Narrative (Details)	3 Months Ended
	Mar. 31, 2019USD ($)
Revenue from Contract with Customer [Abstract]
Contract asset impairment charges	$ 0

REVENUE RECOGNITION - Summary o

REVENUE RECOGNITION - Summary of Disaggregated Revenue by Primary Geographical Market and Timing of Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	$ 100,150	$ 69,972
Products delivered at a point in time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	90,400	59,371
Products and services delivered over time
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	9,750	10,601
United States
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	77,686	43,130
International
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net revenues	$ 22,464	$ 26,842

REVENUE RECOGNITION - Summary_2

REVENUE RECOGNITION - Summary of Contract Assets and Contract Liabilities from Contracts with Customers (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Receivables	$ 81,715	$ 78,938
Short-term contract assets (Prepaid expenses and other assets)	13,595	13,516
Long-term contract assets (Other assets)	34,683	34,148
Short-term contract liabilities (Deferred revenues)	32,916	33,119
Long-term contract liabilities (Deferred revenues)	$ 78,393	$ 76,911

REVENUE RECOGNITION - Summary_3

REVENUE RECOGNITION - Summary of Significant Changes in the Balances of Contract Liabilities and Assets (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Contract Assets
Balance, beginning of period	$ 47,664
Amount recognized	(3,594)
Increase	4,208
Balance, end of period	48,278
Contract Liabilities
Balance, beginning of period	110,030
Revenue recognized	(9,750)
Increase due to billings	11,029
Balance, end of period	$ 111,309

REVENUE RECOGNITION - Summary_4

REVENUE RECOGNITION - Summary of Estimated Revenue Expected to be Recognized in Future Periods (Details) $ in Thousands	Mar. 31, 2019USD ($)
Revenue from Contract with Customer [Abstract]
Total estimated revenue expected to be recognized in future periods	$ 111,309
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Revenue from Contract with Customer [Abstract]
Total estimated revenue expected to be recognized in future periods	$ 26,092
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated revenue expected to be recognized in future periods, expected timing	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue from Contract with Customer [Abstract]
Total estimated revenue expected to be recognized in future periods	$ 27,797
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated revenue expected to be recognized in future periods, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue from Contract with Customer [Abstract]
Total estimated revenue expected to be recognized in future periods	$ 21,626
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated revenue expected to be recognized in future periods, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue from Contract with Customer [Abstract]
Total estimated revenue expected to be recognized in future periods	$ 16,594
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated revenue expected to be recognized in future periods, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue from Contract with Customer [Abstract]
Total estimated revenue expected to be recognized in future periods	$ 10,801
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated revenue expected to be recognized in future periods, expected timing	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue from Contract with Customer [Abstract]
Total estimated revenue expected to be recognized in future periods	$ 8,399
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Total estimated revenue expected to be recognized in future periods, expected timing

OTHER FINANCIAL INFORMATION - A

OTHER FINANCIAL INFORMATION - Accounts Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounts receivable	$ 83,855	$ 81,076
Allowance for doubtful accounts	(2,140)	(2,138)
Accounts receivable, net	$ 81,715	$ 78,938

OTHER FINANCIAL INFORMATION - I

OTHER FINANCIAL INFORMATION - Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 950	$ 970
Finished goods	12,021	15,297
Total inventory	$ 12,971	$ 16,267

OTHER FINANCIAL INFORMATION -_2

OTHER FINANCIAL INFORMATION - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Salaries, commissions, incentive compensation and benefits	$ 6,442	$ 4,107
Customer rebates and sales incentives	8,769	8,527
Freight	7,599	7,286
Other	9,621	9,090
Total accrued liabilities	$ 32,431	$ 29,010

GOODWILL AND INTANGIBLE ASSET_2

GOODWILL AND INTANGIBLE ASSETS - Schedule of Goodwill and Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Mar. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Goodwill, Gross	$ 3,664	$ 24,783
Goodwill, Additions	21,119
Goodwill, Net	24,783	24,783
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Other indefinite-lived intangibles, Gross	286	286
Other indefinite-lived intangibles, Additions	0
Intangible assets with finite lives:
Gross	1,951	38,151
Additions	36,200
Accumulated Amortization	(2,845)	(4,027)
Net	35,306	34,124
Patents and licensed technology
Intangible assets with finite lives:
Gross	1,665	1,665
Additions	0
Accumulated Amortization	(1,665)	(1,665)
Net	0	0
Developed technology
Intangible assets with finite lives:
Gross	0	13,100
Additions	13,100
Accumulated Amortization	(909)	(1,455)
Net	12,191	11,645
Customer relationship
Intangible assets with finite lives:
Gross	0	23,100
Additions	23,100
Accumulated Amortization	(271)	(907)
Net	$ 22,829	$ 22,193

GOODWILL AND INTANGIBLE ASSET_3

GOODWILL AND INTANGIBLE ASSETS - Amortization Expense (Details) - USD ($) $ in Thousands	Aug. 09, 2018	Mar. 31, 2019	Mar. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets		$ 1,182	$ 76
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets		546	76
Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets		$ 636	$ 0
SunPower’s
Finite-Lived Intangible Assets [Line Items]
Agreement for exclusive supplier rights, period	5 years
SunPower’s | Developed Technology
Finite-Lived Intangible Assets [Line Items]
Amortization period for acquired intangible assets	6 years
SunPower’s | Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Amortization period for acquired intangible assets	9 years

WARRANTY OBLIGATIONS - Summary

WARRANTY OBLIGATIONS - Summary of Warranty Activities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Changes in the Company's product warranty liability
Warranty obligations, beginning of period	$ 31,294	$ 29,816
Accruals for warranties issued during period	858	758
Changes in estimates	804	1,450
Settlements	(2,296)	(1,676)
Increase due to accretion expense	551	419
Other	(169)	(142)
Warranty obligations, end of period	31,042	30,625
Less current portion	(7,925)	(7,699)	$ (8,083)
Noncurrent	$ 23,117	$ 22,926	$ 23,211

FAIR VALUE MEASUREMENTS - Sched

FAIR VALUE MEASUREMENTS - Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Recurring - Total warranty obligations - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value liabilities, current	$ 4,237	$ 4,288
Fair value liabilities, non-current	7,828	7,469
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value liabilities	$ 12,065	$ 11,757	$ 11,720	$ 9,791

FAIR VALUE MEASUREMENTS - Sch_2

FAIR VALUE MEASUREMENTS - Schedule of Changes in Nonfinancial Liabilities Related to Warrant Obligations Measured at Fair Value on a Recurring Basis Using Significant Unobservable Inputs (Details) - Level 3 - Recurring - Total warranty obligations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	$ 11,757	$ 9,791
Accruals for warranties issued during period	858	758
Changes in estimates	341	1,785
Settlements	(1,272)	(891)
Increase due to accretion expense	551	419
Other	(170)	(142)
Balance at end of period	$ 12,065	$ 11,720

FAIR VALUE MEASUREMENTS - Narra

FAIR VALUE MEASUREMENTS - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Fair Value Disclosures [Abstract]
Increase in liability as a result of decreasing the profit element and risk premium input by 100 basis points	$ 0.1
Decrease in liability as a result of increasing the profit element and risk premium input by 100 basis points	0.1
Increase to fair value measurement as a result of 100 basis point decrease	0.5
Decrease to fair value measurement as a result of 100 basis point increase	$ 0.5

FAIR VALUE MEASUREMENTS - Summa

FAIR VALUE MEASUREMENTS - Summary of Significant Unobservable Inputs used in the Fair Value Measurement of Liabilities Designated as Level 3 (Details) - Recurring - Level 3 - Warranty obligations for microinverters sold since January 1, 2014	Mar. 31, 2019	Dec. 31, 2018
Measurement Input, Profit Element and Risk Premium
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warranty obligations for microinverters sold since January 1, 2014	0.14	0.16
Measurement Input, Entity Credit Risk
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Warranty obligations for microinverters sold since January 1, 2014	0.18	0.19

RESTRUCTURING - Summary of Rest

RESTRUCTURING - Summary of Restructuring Charges (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 368	$ 0
Redundancy and employee severance and benefit arrangements
Restructuring Cost and Reserve [Line Items]
Restructuring charges	468	0
Lease loss reserves
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Accrual Adjustment	$ (100)	$ 0

RESTRUCTURING - Rollforward (De

RESTRUCTURING - Rollforward (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Restructuring Plan 2018
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning	$ 1,192
Charges	468
Cash payments	(752)
Non-cash settlement and other	(343)
Restructuring reserve, ending	565
Restructuring Plan 2018 | Employee Severance and Benefits
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning	904
Charges	468
Cash payments	(752)
Non-cash settlement and other	(55)
Restructuring reserve, ending	565
Restructuring Plan 2018 | Lease Loss Reserves and Contractual Obligations
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning	288
Charges	0
Cash payments	0
Non-cash settlement and other	(288)
Restructuring reserve, ending	0
Restructuring Plan 2016 | Lease Loss Reserves and Contractual Obligations
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning	1,591
Non-cash settlement and other	(1,591)
Restructuring reserve, ending	$ 0

DEBT - Long term debt (Details)

DEBT - Long term debt (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total carrying amount of debt	$ 68,391	$ 109,783
Debt, current	(2,985)	(28,155)
Debt, noncurrent	65,406	81,628
Convertible Notes Payable | Convertible Senior Notes Due 2023
Debt Instrument [Line Items]
Carrying amount of long term debt	65,000	65,000
Less unamortized discount and issuance costs	(2,232)	(2,361)
Total carrying amount of debt	62,768	62,639
Secured Debt | Term Loan Agreement, July 2016
Debt Instrument [Line Items]
Carrying amount of long term debt	0	41,524
Less unamortized discount and issuance costs	0	(1,059)
Total carrying amount of debt	0	40,465
Debt, current	0	(25,417)
Financing Receivable | Financing Receivable Recorded as Debt
Debt Instrument [Line Items]
Carrying amount of long term debt	5,623	6,679
Less value of future purchase option	0	0
Total carrying amount of debt	5,623	6,679
Debt, current	$ (2,985)	$ (2,738)

DEBT - Term Loan (Details)

DEBT - Term Loan (Details) - USD ($)	Jan. 28, 2019	Feb. 28, 2017	Jul. 31, 2016
Debt Instrument [Line Items]
Repayments of Debt	$ 39,500,000
Tennenbaum Capital Partners, LLC | Secured Debt | Amended Tennenbaum Capital Partners LLC Agreement
Debt Instrument [Line Items]
Debt instrument face amount		$ 25,000,000	$ 25,000,000

COMMITMENTS AND CONTINGENCt L_3

COMMITMENTS AND CONTINGENCt LIABILITIES - Narrative (Details)	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Term of lease contract, renewal term	12 years

COMMITMENTS AND CONTINGENCt L_4

COMMITMENTS AND CONTINGENCt LIABILITIES - Lease Components (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 499
Lease liabilities, current (Accrued liabilities)	2,181
Lease liabilities, non-current (Other liabilities)	7,837
Total lease liabilities	$ 10,018
Weighted average remaining lease term	4 years 4 months 24 days
Weighted average discount rate	9.20%
Cash paid for amounts included in the measurement of lease liabilities	$ 737

COMMITMENTS AND CONTINGENCt L_5

COMMITMENTS AND CONTINGENCt LIABILITIES - Schedule of Minimum Lease Payments Under Noncancelable Operating Leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2019 (remaining nine months)	$ 2,248
2020	3,071
2021	3,155
2022	1,717
2023	893
Thereafter	1,227
Total operating lease minimum payments	12,311
Sublease income to be recognized in the future under noncancelable subleases	(2,293)
Total lease liabilities	$ 10,018

STOCK-BASED COMPENSATION Summar

STOCK-BASED COMPENSATION Summary of the Components of Total Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 3,289	$ 1,571
Total unrecognized compensation cost	$ 30,300
Weighted-average recognition period for unrecognized compensation cost	2 years 1 month 6 days
Cost of revenues
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 231	198
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	716	618
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	999	361
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	1,288	394
Restructuring
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 55	$ 0

STOCK-BASED COMPENSATION Summ_2

STOCK-BASED COMPENSATION Summary of Stock-Based Compensation Associated with Each Type of Award (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,289	$ 1,571
Stock options and RSUs and PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	3,222	1,317
Employee stock purchase plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 67	$ 254

STOCK-BASED COMPENSATION Summ_3

STOCK-BASED COMPENSATION Summary of the Weighted-Average Grant Date Fair Value of Options Granted (Details) - Stock options	3 Months Ended
	Mar. 31, 2018$ / shares
The fair value of each option granted during the periods
Weighted average grant date fair value (in usd per share)	$ 1.83
Expected term	4 years 2 months 12 days
Expected volatility	86.40%
Annual risk-free rate of return	2.40%
Dividend yield	0.00%

STOCK-BASED COMPENSATION Summ_4

STOCK-BASED COMPENSATION Summary of Stock Option Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Number of Shares Outstanding
Outstanding, beginning balance (in shares) | shares	6,772
Granted (in shares) | shares	0
Exercised (in shares) | shares	(1,573)
Canceled (in shares) | shares	(55)
Outstanding, ending balance (in shares) | shares	5,144
Shares outstanding, vested and expected to vest (in shares) | shares	5,144
Shares outstanding, exercisable (in shares) | shares	3,318
Weighted- Average Exercise Price per Share
Outstanding, beginning balance (in usd per share)	$ 1.76
Granted (in usd per share)	0
Exercised (in usd per share)	1.06
Canceled (in usd per share)	5.55
Outstanding, ending balance (in usd per share)	1.94
Weighted-average exercise price, vested and expected (in usd per share)	1.94
Weighted-average exercise price, exercisable (in usd per share)	$ 2.20
Weighted-Average Remaining Contractual Term
Outstanding	4 years 10 months
Vested and expected to vest	4 years 10 months
Exercisable	4 years 7 months
Aggregate Intrinsic Value
Exercised | $	$ 10,715
Outstanding | $	37,671
Vested and expected to vest | $	37,671
Exercisable | $	$ 23,471
Share price (in USD per share)	$ 9.23

STOCK-BASED COMPENSATION Summ_5

STOCK-BASED COMPENSATION Summary of Stock Options Outstanding (Details) shares in Thousands	3 Months Ended
	Mar. 31, 2019$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding - Number of Shares (shares) | shares	5,144
Options Outstanding - Weighted- Average Remaining Life	4 years 10 months
Options Outstanding - Weighted- Average Exercise Price (usd per share) | $ / shares	$ 1.94
Options Exercisable - Number of Shares Exercisable (shares) | shares	3,318
Options Exercisable - Weighted-average Exercise Price (usd per share) | $ / shares	$ 2.20
$0.27 —– $1.14
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding - Number of Shares (shares) | shares	1,061
Options Outstanding - Weighted- Average Remaining Life	5 years 7 months
Options Outstanding - Weighted- Average Exercise Price (usd per share) | $ / shares	$ 0.83
Options Exercisable - Number of Shares Exercisable (shares) | shares	703
Options Exercisable - Weighted-average Exercise Price (usd per share) | $ / shares	$ 0.79
$1.29 —– $1.29
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding - Number of Shares (shares) | shares	1,000
Options Outstanding - Weighted- Average Remaining Life	5 years 6 months
Options Outstanding - Weighted- Average Exercise Price (usd per share) | $ / shares	$ 1.29
Options Exercisable - Number of Shares Exercisable (shares) | shares	375
Options Exercisable - Weighted-average Exercise Price (usd per share) | $ / shares	$ 1.29
$1.31 —– $1.31
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding - Number of Shares (shares) | shares	1,752
Options Outstanding - Weighted- Average Remaining Life	5 years
Options Outstanding - Weighted- Average Exercise Price (usd per share) | $ / shares	$ 1.31
Options Exercisable - Number of Shares Exercisable (shares) | shares	1,230
Options Exercisable - Weighted-average Exercise Price (usd per share) | $ / shares	$ 1.31
$1.37 —– $6.98
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding - Number of Shares (shares) | shares	1,034
Options Outstanding - Weighted- Average Remaining Life	3 years 10 months
Options Outstanding - Weighted- Average Exercise Price (usd per share) | $ / shares	$ 2.90
Options Exercisable - Number of Shares Exercisable (shares) | shares	713
Options Exercisable - Weighted-average Exercise Price (usd per share) | $ / shares	$ 3.03
$7.01 —– $12.57
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding - Number of Shares (shares) | shares	297
Options Outstanding - Weighted- Average Remaining Life	2 years 2 months
Options Outstanding - Weighted- Average Exercise Price (usd per share) | $ / shares	$ 8.40
Options Exercisable - Number of Shares Exercisable (shares) | shares	297
Options Exercisable - Weighted-average Exercise Price (usd per share) | $ / shares	$ 8.40

STOCK-BASED COMPENSATION Summ_6

STOCK-BASED COMPENSATION Summary of Restricted Stock Unit Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Weighted-Average Remaining Contractual Term
Outstanding	1 year 6 months
Aggregate Intrinsic Value
Share price (in USD per share)	$ 9.23
Restricted stock units
Number of Shares Outstanding
Outstanding, beginning balance (in shares) | shares	4,352
Granted (in shares) | shares	1,114
Vested (in shares) | shares	(716)
Canceled (in shares) | shares	(216)
Outstanding, ending balance (in shares) | shares	4,534
Number of shares outstanding, expected to vest (in shares) | shares	4,532
Weighted Average Fair Value per Share at Grant Date
Outstanding, beginning balance (in usd per share)	$ 3.52
Granted (in usd per share)	8.12
Vested (in usd per share)	3.70
Canceled (in usd per share)	2.02
Outstanding, ending balance (in usd per share)	4.70
Weighted-Average Fair Value per Share at Grant Date, Expected to vest (in usd per share)	$ 4.70
Weighted-Average Remaining Contractual Term
Expected to vest	1 year 6 months
Aggregate Intrinsic Value
Vested | $	$ 6,255
Outstanding | $	41,845
Expected to vest | $	$ 41,835

STOCK-BASED COMPENSATION Summ_7

STOCK-BASED COMPENSATION Summary of Performance Stock Unit Activity (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Weighted-Average Remaining Contractual Term
Outstanding	1 year 6 months
Aggregate Intrinsic Value
Share price (in USD per share)	$ 9.23
Performance Shares
Number of Shares Outstanding
Outstanding, beginning balance (in shares) | shares	1,330
Granted (in shares) | shares	1,046
Vested (in shares) | shares	(1,026)
Canceled (in shares) | shares	(337)
Outstanding, ending balance (in shares) | shares	1,013
Number of shares outstanding, expected to vest (in shares) | shares	1,013
Weighted Average Fair Value per Share at Grant Date
Outstanding, beginning balance (in usd per share)	$ 4.66
Granted (in usd per share)	9.40
Vested (in usd per share)	4.63
Canceled (in usd per share)	4.78
Outstanding, ending balance (in usd per share)	8.64
Weighted-Average Fair Value per Share at Grant Date, Expected to vest (in usd per share)	$ 8.64
Weighted-Average Remaining Contractual Term
Outstanding	1 year
Expected to vest	1 year
Aggregate Intrinsic Value
Vested | $	$ 9,925
Outstanding | $	9,349
Expected to vest | $	$ 9,349

NET INCOME (LOSS) PER SHARE - S

NET INCOME (LOSS) PER SHARE - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net income (loss)	$ 2,765	$ (5,128)
Denominator:
Weighted average common shares outstanding (in shares)	108,195	91,422
Employee stock-based awards	7,668	0
Weighted average common shares outstanding for diluted calculation	115,863	91,422
Net loss per share, basic (in USD per share)	$ 0.03	$ (0.06)
Net income (loss) per share, diluted (in usd per share)	$ 0.02	$ (0.06)

NET INCOME (LOSS) PER SHARE -_2

NET INCOME (LOSS) PER SHARE - Schedule of Potentially Dilutive Securities Excluded from the Computation of Diluted Net Loss Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	11,904	12,077
Convertible Notes Payable
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	11,701	0
Employee stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	112	8,418
RSUs and PSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	91	3,659

RELATED PARTY Narrative (Detail

RELATED PARTY Narrative (Details) - SunPower’s - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Common stock held by related party (in shares)	7.5
Revenue from related parties	$ 4.5
Accounts receivable, related parties	$ 5.2	$ 10.3

Uncategorized Items - a2019q110

Label	Element	Value	[1]
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (26,000)
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(38,948,000)
Common Stock Including Additional Paid in Capital [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	0
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 26,000
[1]	Includes the adoption of Accounting Standards Update (“ASU”) 2018-07, “Compensation - Stock Compensation: Improvements to Non-employee Share-Based Payment Accounting” on January 1, 2019 and the adoption of Accounting Standards Codification (“ASC”) No. 606, “Revenue Recognition” on January 1, 2018.