Vivint Solar (VSLR) 10-K 10 Mar 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Mar. 31, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Trading Symbol	VSLR
Entity Registrant Name	VIVINT SOLAR, INC.
Entity Central Index Key	0001607716
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		124,158,478
Entity Public Float			$ 331.9
Entity File Number	001-36642
Entity Tax Identification Number	45-5605880
Entity Address, Address Line One	1800 West Ashton Blvd.
Entity Address, City or Town	Lehi
Entity Address, State or Province	UT
Entity Address, Postal Zip Code	84043
City Area Code	877
Local Phone Number	404-4129
Entity Incorporation, State or Country Code	DE
Title of 12(b) Security	Common Stock, par value $0.01 per share
Security Exchange Name	NYSE
Entity Interactive Data Current	Yes
Document Annual Report	true
Document Transition Report	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents		$ 166,048	$ 219,591
Accounts receivable, net		24,314	14,207
Inventories		20,576	13,257
Prepaid expenses and other current assets		41,137	31,201
Total current assets		252,075	278,256
Restricted cash and cash equivalents		89,892	71,305
Solar energy systems, net		1,759,861	1,938,874
Property and equipment, net		17,500	10,730
Other non-current assets, net		680,062	28,090
TOTAL ASSETS	[1]	2,799,390	2,327,255
Current liabilities:
Accounts payable		59,007	45,929
Distributions payable to non-controlling interests and redeemable non-controlling interests		10,253	7,846
Accrued compensation		34,149	25,520
Current portion of long-term debt		16,405	12,155
Current portion of deferred revenue		40,715	30,199
Current portion of finance lease obligation		2,274	1,921
Accrued and other current liabilities		78,539	42,860
Total current liabilities		241,342	166,430
Long-term debt, net of current portion		1,483,256	1,203,282
Deferred revenue, net of current portion		17,631	13,524
Finance lease obligation, net of current portion		6,443	505
Deferred tax liability, net		583,695	437,120
Other non-current liabilities		74,423	24,610
Total liabilities	[1]	2,406,790	1,845,471
Commitments and contingencies (Note 19)
Redeemable non-controlling interests		115,384	119,572
Stockholders' equity:
Common stock, $0.01 par value—1,000,000 shares authorized, 123,056 shares issued and outstanding as of December 31, 2019; 1,000,000 shares authorized, 120,114 shares issued and outstanding as of December 31, 2018		1,231	1,201
Additional paid-in capital		591,639	574,248
Accumulated other comprehensive loss		(20,436)	(7,223)
Accumulated deficit		(381,961)	(279,631)
Total stockholders' equity		190,473	288,595
Non-controlling interests		86,743	73,617
Total equity		277,216	362,212
TOTAL LIABILITIES, REDEEMABLE NON-CONTROLLING INTERESTS AND EQUITY		$ 2,799,390	$ 2,327,255
[1]	The Company’s consolidated assets as of December 31, 2019 and 2018 include $2,194.3 million and $1,835.8 million consisting of assets of variable interest entities (“VIEs”) that can only be used to settle obligations of the VIEs. These assets include cash and cash equivalents of $82.8 million and $62.4 million as of December 31, 2019 and 2018; accounts receivable, net, of $8.9 million and $6.6 million as of December 31, 2019 and 2018; prepaid expenses and other current assets of $1.7 million and $1.3 million as of December 31, 2019 and 2018; restricted cash and cash equivalents of $8.9 million and $2.4 million as of December 31, 2019 and 2018; solar energy systems, net, of $1,587.4 million and $1,752.3 million as of December 31, 2019 and 2018; and other non-current assets, net of $504.7 million and $10.9 million as of December 31, 2019 and 2018. The Company’s consolidated liabilities as of December 31, 2019 and 2018 included $233.4 million and $80.8 million of liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include distributions payable to non-controlling interests and redeemable non-controlling interests of $10.3 million and $7.8 million as of December 31, 2019 and 2018; accrued and other current liabilities of $6.4 million and $4.9 million as of December 31, 2019 and 2018; long-term debt of $201.6 million and $55.0 million as of December 31, 2019 and 2018; deferred revenue of $14.8 million and $12.0 million as of December 31, 2019 and 2018; and other non-current liabilities of $0.3 million and $1.0 million as of December 31, 2019 and 2018. For further information see Note 14—Investment Funds.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Common stock, par value		$ 0.01	$ 0.01
Common stock, shares authorized		1,000,000,000	1,000,000,000
Common stock, shares issued		123,056,000	120,114,000
Common stock, shares outstanding		123,056,000	120,114,000
Total assets	[1]	$ 2,799,390	$ 2,327,255
Cash and cash equivalents		166,048	219,591
Accounts receivable, net		24,314	14,207
Prepaid expenses and other current assets		41,137	31,201
Restricted cash and cash equivalents		89,892	71,305
Solar energy systems, net		1,759,861	1,938,874
Other non-current assets, net		680,062	28,090
Total liabilities	[1]	2,406,790	1,845,471
Distributions payable to non-controlling interests and redeemable non-controlling interests		10,253	7,846
Accrued and other current liabilities		78,539	42,860
Long-term debt		1,499,661	1,215,437
Other non-current liabilities		74,423	24,610
Variable Interest Entities
Total assets		2,194,274	1,835,834
Cash and cash equivalents		82,764	62,350
Accounts receivable, net		8,922	6,593
Prepaid expenses and other current assets		1,676	1,289
Restricted cash and cash equivalents		8,890	2,443
Solar energy systems, net		1,587,400	1,752,300
Other non-current assets, net		504,668	10,888
Total liabilities		233,354	80,760
Distributions payable to non-controlling interests and redeemable non-controlling interests		10,253	7,846
Accrued and other current liabilities		6,394	4,860
Long-term debt		201,600	55,000
Deferred revenue		14,800	12,000
Other non-current liabilities		$ 301	$ 1,023
[1]	The Company’s consolidated assets as of December 31, 2019 and 2018 include $2,194.3 million and $1,835.8 million consisting of assets of variable interest entities (“VIEs”) that can only be used to settle obligations of the VIEs. These assets include cash and cash equivalents of $82.8 million and $62.4 million as of December 31, 2019 and 2018; accounts receivable, net, of $8.9 million and $6.6 million as of December 31, 2019 and 2018; prepaid expenses and other current assets of $1.7 million and $1.3 million as of December 31, 2019 and 2018; restricted cash and cash equivalents of $8.9 million and $2.4 million as of December 31, 2019 and 2018; solar energy systems, net, of $1,587.4 million and $1,752.3 million as of December 31, 2019 and 2018; and other non-current assets, net of $504.7 million and $10.9 million as of December 31, 2019 and 2018. The Company’s consolidated liabilities as of December 31, 2019 and 2018 included $233.4 million and $80.8 million of liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include distributions payable to non-controlling interests and redeemable non-controlling interests of $10.3 million and $7.8 million as of December 31, 2019 and 2018; accrued and other current liabilities of $6.4 million and $4.9 million as of December 31, 2019 and 2018; long-term debt of $201.6 million and $55.0 million as of December 31, 2019 and 2018; deferred revenue of $14.8 million and $12.0 million as of December 31, 2019 and 2018; and other non-current liabilities of $0.3 million and $1.0 million as of December 31, 2019 and 2018. For further information see Note 14—Investment Funds.

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Revenue:
Total revenue	$ 341,041	$ 290,321
Cost of revenue:
Total cost of revenue	258,546	248,295
Gross profit	82,495	42,026
Operating expenses:
Sales and marketing	151,194	58,950
Research and development	2,043	1,867
General and administrative	117,822	93,703
Total operating expenses	271,059	154,520
Loss from operations	(188,564)	(112,494)
Interest expense, net	82,323	65,308
Other expense (income), net	1,434	(4,538)
Loss before income taxes	(272,321)	(173,264)
Income tax expense	150,999	106,299
Net loss	(423,320)	(279,563)
Net loss attributable to non-controlling interests and redeemable non-controlling interests	(321,145)	(263,971)
Net loss attributable to common stockholders	$ (102,175)	$ (15,592)
Net loss attributable per share to common stockholders:
Basic and diluted	$ (0.84)	$ (0.13)
Weighted-average shares used in computing net loss attributable per share to common stockholders:
Basic and diluted	121,310	117,565
Customer Agreements and Incentives
Revenue:
Total revenue	$ 217,331	$ 174,066
Cost of revenue:
Total cost of revenue	186,325	164,920
Solar Energy System and Product Sales
Revenue:
Total revenue	123,710	116,255
Cost of revenue:
Total cost of revenue	$ 72,221	$ 83,375

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss attributable to common stockholders	$ (102,175)	$ (15,592)
Other comprehensive loss:
Unrealized losses on cash flow hedging instruments (net of tax effect of $(5,358) and $(606) in 2019 and 2018)	(14,295)	(1,705)
Less: Interest (expense) income on derivatives recognized into earnings (net of tax effect of $(385) and $5,860 in 2019 and 2018)	(1,082)	15,741
Total other comprehensive loss	(13,213)	(17,446)
Comprehensive loss	$ (115,388)	$ (33,038)

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Unrealized losses on cash flow hedging instruments, tax	$ (5,358)	$ (606)
Interest expense on derivatives recognized into earnings, tax	$ (385)	$ 5,860

Consolidated Statements of Rede

Consolidated Statements of Redeemable Non-Controlling Interests and Equity - USD ($) shares in Thousands, $ in Thousands	Total	Redeemable Non-Controlling Interests	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings (Accumulated Deficit)	Total Stockholders Equity	Non-Controlling Interests
Balance at Dec. 31, 2017	$ 861,066	$ 122,444	$ 1,151	$ 559,788	$ 6,905	$ 213,107	$ 780,951	$ 80,115
Balance (in Shares) at Dec. 31, 2017			115,099
Cumulative-effect adjustment from adoption of new ASUs	(473,828)				3,318	(477,146)	(473,828)
Stock-based compensation expense	13,163			13,163			13,163
Issuance of common stock, net	1,347		$ 50	1,297			1,347
Issuance of common stock, net (in shares)			5,015
Contributions from non-controlling interests and redeemable non-controlling interests	221,388	79,354						221,388
Distributions to non-controlling interests and redeemable non-controlling interests	(36,328)	(9,813)						(36,328)
Total other comprehensive loss	(17,446)				(17,446)		(17,446)
Net loss	(207,150)	(72,413)				(15,592)	(15,592)	(191,558)
Balance at Dec. 31, 2018	$ 362,212	119,572	$ 1,201	574,248	(7,223)	(279,631)	288,595	73,617
Balance (in Shares) at Dec. 31, 2018	120,114		120,114
Cumulative-effect adjustment from adoption of new ASUs	$ (155)					(155)	(155)
Stock-based compensation expense	16,418			16,418			16,418
Issuance of common stock, net	1,003		$ 30	973			1,003
Issuance of common stock, net (in shares)			2,942
Contributions from non-controlling interests and redeemable non-controlling interests	363,397	20,974						363,397
Distributions to non-controlling interests and redeemable non-controlling interests	(43,821)	(10,467)						(43,821)
Total other comprehensive loss	(13,213)				(13,213)		(13,213)
Net loss	(408,625)	(14,695)				(102,175)	(102,175)	(306,450)
Balance at Dec. 31, 2019	$ 277,216	$ 115,384	$ 1,231	$ 591,639	$ (20,436)	$ (381,961)	$ 190,473	$ 86,743
Balance (in Shares) at Dec. 31, 2019	123,056		123,056

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (423,320)	$ (279,563)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	81,930	69,634
Deferred income taxes	151,548	106,862
Stock-based compensation	16,418	13,163
Loss on solar energy systems and property and equipment	17,493	7,400
Noncash interest and other expense	8,841	17,006
Reduction in lease pass-through financing obligation	(4,654)	(4,433)
Gains on interest rate swaps	(4,377)	(148)
Changes in operating assets and liabilities:
Accounts receivable, net	(10,107)	5,458
Inventories	(7,319)	9,340
Prepaid expenses and other current assets	(5,998)	2,805
Other non-current assets, net	(182,108)	(7,828)
Accounts payable	(1)	1,898
Accrued compensation	8,349	4,762
Deferred revenue	14,623	(926)
Accrued and other liabilities	15,515	8,915
Net cash used in operating activities	(323,167)	(45,655)
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments for the cost of solar energy systems	(314,932)	(331,716)
Payments for property and equipment	(1,984)	(543)
Proceeds from disposals of solar energy systems and property and equipment	3,453	3,379
Purchase of intangible assets	(2,373)	(223)
Net cash used in investing activities	(315,836)	(329,103)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from investment by non-controlling interests and redeemable non-controlling interests	384,371	300,742
Distributions paid to non-controlling interests and redeemable non-controlling interests	(51,881)	(54,732)
Proceeds from long-term debt	563,480	984,425
Payments on long-term debt	(279,054)	(700,143)
Payments for debt issuance and deferred offering costs	(16,053)	(21,209)
Proceeds from lease pass-through financing obligation	3,661	3,609
Principal payments on finance lease obligations	(1,480)	(3,323)
Proceeds from issuance of common stock	1,003	1,347
Net cash provided by financing activities	604,047	510,716
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS, INCLUDING RESTRICTED AMOUNTS	(34,956)	135,958
CASH AND CASH EQUIVALENTS, INCLUDING RESTRICTED AMOUNTS—Beginning of period	290,896	154,938
CASH AND CASH EQUIVALENTS, INCLUDING RESTRICTED AMOUNTS—End of period	255,940	290,896
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Cash paid for interest, net	74,534	42,928
Cash recovered from income taxes, net	(2,118)	(11,194)
NONCASH INVESTING AND FINANCING ACTIVITIES:
Costs of solar energy systems included in changes in accounts payable, accrued compensation and accrued and other liabilities	60,178	8,503
Right-of-use assets obtained in exchange for new operating lease liabilities	12,217
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 9,482	$ 1,622

Organization

Organization	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	1. Vivint Solar, Inc. and its subsidiaries are collectively referred to as the “Company.” The Company most commonly offers solar energy to residential customers through long-term customer contracts, such as power purchase agreements (“PPAs”) and legal-form leases (“Solar Leases”). The Company has formed various investment funds and entered into long-term debt facilities to monetize the recurring customer payments under its long-term customer contracts and investment tax credits (“ITCs”), accelerated tax depreciation and other incentives associated with residential solar energy systems. The Company uses the cash received from the investment funds, long-term debt facilities and cash generated from operations, including System Sales, to finance a portion of the Company’s variable and fixed costs associated with installing solar energy systems.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) and reflect the accounts and operations of the Company, its subsidiaries in which the Company has a controlling financial interest and the investment funds formed to fund the purchase of solar energy systems under long-term customer contracts, which are consolidated as variable interest entities (“VIEs”). The Company uses a qualitative approach in assessing the consolidation requirement for VIEs. This approach focuses on determining whether the Company has the power to direct the activities of the VIE that most significantly affect the VIE’s economic performance and whether the Company has the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. All of these determinations involve significant management judgments. The Company has determined that it is the primary beneficiary in the operational VIEs in which it has an equity interest. The Company evaluates its relationships with the VIEs on an ongoing basis to ensure that it continues to be the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. For additional information regarding these VIEs, see Note 14—Investment Funds. Beginning with the first quarter of 2019, the consolidated statements of operations items formerly captioned “Operating leases and incentives” and “Cost of revenue—operating leases and incentives” are now captioned “Customer agreements and incentives” and “Cost of revenue—customer agreements and incentives.” Also beginning with the first quarter of 2019, the consolidated balance sheet items formerly captioned “Current portion of capital lease obligation” and “Capital lease obligation, net of current portion” are now captioned “Current portion of finance lease obligation” and “Finance lease obligation, net of current portion.” Amounts in these balance sheet items were capital leases under Accounting Standards Codification 840: Leases (“Topic 840”) in periods ending prior to January 1, 2019, while amounts in these balance sheet items are finance leases under Accounting Standards Codification 842: Leases (“Topic 842”) in periods ending subsequent to January 1, 2019. See “—Leases” below for further explanation of these changes. Use of Estimates The preparation of the consolidated financial statements requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. The Company regularly makes significant estimates and assumptions including, but not limited to, ITCs; revenue recognition; solar energy systems, net; the impairment analysis of long-lived assets; stock-based compensation; the provision for income taxes; the valuation of derivative financial instruments; the recognition and measurement of loss contingencies; and non-controlling interests and redeemable non-controlling interests. The Company bases its estimates on historical experience and on various other assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ materially from those estimates. Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less at the time of purchase to be cash and cash equivalents. Cash equivalents consist principally of time deposits and money market accounts with high quality financial institutions. Restricted Cash The Company’s guaranty agreements with certain of its fund investors require the maintenance of minimum cash balances of $10.0 million. For additional information, see Note 14—Investment Funds. As of December 31, 2019, the Company also had $79.9 million in required reserves outstanding in separate collateral accounts in accordance with the terms of its various debt obligations. For additional information, see Note 11—Debt Obligations. These minimum cash balances are classified as restricted cash. Liquidity In order to grow, the Company requires cash to finance the deployment of solar energy systems. As of the date of this filing, the Company will require additional sources of cash beyond current cash balances, and currently available financing facilities to fund long-term planned growth. If the Company is unable to secure additional financing when needed, or upon desirable terms, the Company may be unable to finance installation of customers’ systems in a manner consistent with past performance, cost of capital could increase, or the Company may be required to significantly reduce the scope of operations, any of which would have a material adverse effect on the business, financial condition, results of operations and prospects. While the Company believes additional financing is available and will continue to be available to support current levels of operations, the Company believes it has the ability and intent to reduce operations to the level of available financial resources for at least the next 12 months from the date of this report, if necessary. Accounts Receivable, Net Accounts receivable are recorded at the invoiced amount, net of allowance for doubtful accounts. Accounts receivable also include unbilled accounts receivable, which is composed of the monthly PPA power generation not yet invoiced and the monthly bill rate of Solar Leases as of the end of the reporting period. The Company estimates its allowance for doubtful accounts based upon the collectability of the receivables in light of historical trends and adverse situations that may affect customers’ ability to pay. Revisions to the allowance are recorded as an adjustment to bad debt expense or as a reduction to revenue when collectability is not reasonably assured. After appropriate collection efforts are exhausted, specific accounts receivable deemed to be uncollectible would be charged against the allowance in the period they are deemed uncollectible. Recoveries of accounts receivable previously written-off are recorded as credits to bad debt expense. The Company had an allowance for doubtful accounts of $9.4 million and $5.2 million as of December 31, 2019 and 2018. Inventories Inventories include solar energy systems under construction that have yet to be interconnected to the power grid and that will be sold to customers. Inventory is stated at the lower of cost, on a first-in, first-out (“FIFO”) basis, or net realizable value. Upon interconnection to the power grid, solar energy system inventory is removed using the specific identification method. Inventories also include components related to photovoltaic installation products and are stated at the lower of cost, on an average cost basis, or net realizable value. The Company evaluates its inventory reserves on a quarterly basis and writes down the value of inventories for estimated excess and obsolete inventories based on assumptions about future demand and market conditions. See Note 4—Inventories. Concentrations of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. The associated concentration risk for cash and cash equivalents is mitigated by banking with creditworthy institutions. At certain times, amounts on deposit exceed Federal Deposit Insurance Corporation insurance limits. Approximately $11.6 million, or 48% of accounts receivable, net as of December 31, 2019 was due from three third-party loan providers that offer financing to System Sales customers. The Company does not require collateral or other security to support accounts receivable. The Company is not dependent on any single customer outside of the third-party loan providers. The Company purchases solar panels, inverters and other system components from a limited number of suppliers. Two suppliers accounted for approximately 91% of the Company’s solar photovoltaic module purchases for the year ended December 31, 2019. Two suppliers accounted for substantially all of the Company’s inverter purchases for the year ended December 31, 2019. If these suppliers fail to satisfy the Company’s requirements on a timely basis or if the Company fails to develop, maintain and expand its relationship with these suppliers, the Company could suffer delays in being able to deliver or install its solar energy systems, experience a possible loss of revenue, or incur higher costs, any of which could adversely affect its operating results. Additionally, certain of the subcomponents of the Company’s equipment are sourced from Asia, including China and other countries in Southeast Asia that have been, or may be, significantly impacted by the coronavirus outbreak. To date, the Company has not seen widespread impacts to its supply but is closely monitoring the situation. Supply chain disruptions could reduce the availability of key components, increase prices or both. If the Company fails to identify or to qualify alternative products on commercially reasonable terms the Company’s operating results and growth prospects would be adversely affected. In addition, the macroeconomic effects of the coronavirus outbreak in China and other markets could result in a widespread health crisis that could adversely affect the economies and financial markets of many countries, resulting in an economic downturn that could affect demand for the Company’s products and likely impact its operating results. Megawatts installed in California accounted for approximately 46% and 38% of total megawatts installed for the years ended December 31, 2019 and 2018. Megawatts installed in the Northeastern United States accounted for approximately 26% and 32% of total megawatts installed for the years ended December 31, 2019 and 2018. Future operations could be affected by changes in the economic conditions in these and other geographic areas, by changes in materials costs, by changes in the demand for renewable energy generated by solar energy systems or by changes or eliminations of solar energy related government incentives. Fair Value of Financial Instruments Assets and liabilities recorded at fair value on a recurring basis in the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: • Level I—Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; • Level II—Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and • Level III—Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. The Company’s financial instruments measured on a recurring basis consist of Level II assets. See Note 3—Fair Value Measurements. Investment Tax Credits (ITCs) The Company receives ITCs under Section 48(a) of the Internal Revenue Code. The amount of the ITC is equal to 30% of the basis of eligible solar property as long as construction of the solar energy system began by December 31, 2019. The Company receives minimal allocations of ITCs for solar energy systems placed in its investment funds as the majority of such credits are allocated to the fund investors. Some of the Company’s investment funds obligate it to make certain fund investors whole for losses that the investors may suffer in certain limited circumstances resulting from the disallowance or recapture of ITCs as a result of the Internal Revenue Service’s (the “IRS”) assessment of the fair value of such systems. The Company has concluded that the likelihood of a recapture event related to these assessments is remote and consequently has not recorded any liability in the consolidated financial statements for any potential recapture exposure. However, several recent investment funds and debt obligations have required the Company to prepay insurance premiums to cover the risk of ITC recapture. The Company amortizes this prepaid insurance expense over the ITC recapture period. The Company receives all ITCs for solar energy systems that are not sold to customers or placed in its investment funds. The Company accounts for its ITCs as a reduction of income tax expense in the year in which the credits arise. Leases The Company adopted Topic 842 and its subsequent updates effective January 1, 2019. These updates are intended to increase transparency and comparability among organizations by recognizing right-of-use assets and lease liabilities on the consolidated balance sheets and disclosing key information about leasing arrangements. The Company utilized the additional transition method permitted by Accounting Standards Update (“ASU”) 2018-11 and adopted Topic 842 using a modified retrospective method with a cumulative-effect adjustment to its accumulated deficit as of January 1, 2019. As such, comparative periods ending prior to January 1, 2019 are presented in accordance with Topic 840 and periods ending after January 1, 2019 are presented in accordance with Topic 842. The impact to the accumulated deficit as a result of adopting ASU 2016-02 was a net reduction of approximately $0.2 million. The Company did not use the transitionary practical expedients allowed under Topic 842, and as such, the Company reassessed all contracts existing at the adoption date of January 1, 2019. The Company elected to treat leases with lease terms of 12 months or less as short-term leases. No right-of-use assets or lease liabilities are recognized for short-term leases. The Company has also elected not to separate lease components from non-lease components for all classes of leased assets except for building leases. The adoption of this ASU resulted in right-of-use assets of $34.6 million related to operating leases being recognized in other non-current assets, net on the consolidated balance sheets as of January 1, 2019. Corresponding lease liabilities of $43.8 million related to operating leases were recognized on the consolidated balance sheets as of January 1, 2019, with the current portion recognized in accrued and other current liabilities and the long-term portion recognized in other non-current liabilities. In addition, at January 1, 2019, approximately $1.0 million of lease-related liabilities were removed from accrued and other current liabilities and approximately $8.2 million of lease-related liabilities were removed from other non-current liabilities and included as reductions to the initial operating lease right-of-use assets. As of January 1, 2019, finance lease right-of-use assets of $0.9 million continued to be recorded in property and equipment, net. Any changes in lease terms or estimates subsequent to adoption of the ASU 2016-02 are reflected in the right-of-use assets and lease liabilities. The Company’s PPAs, Solar Leases, and associated rebates and incentives no longer meet the definition of a lease under Topic 842. Accordingly, they are accounted for in accordance with Accounting Standards Codification 606: Revenue from Contracts with Customers (“Topic 606”) beginning on January 1, 2019. The Company concluded that there was no change to its revenue recognition practices for its PPA revenue stream under Topic 606. For Solar Leases, the Company concluded that the impact of applying Topic 606 is immaterial. The Company also concluded that there was no material change related to the timing of revenue recognition for rebates and incentives under Topic 606. Upon the adoption of Topic 842, the Company no longer capitalizes initial direct costs and amortizes them to the respective cost of revenue line items. Instead, the Company now capitalizes costs of obtaining a contract which meet the “incremental” criteria defined in Accounting Standards Codification 340 to other non-current assets, net. These costs are now amortized over the period of benefit to sales and marketing expense on the consolidated statements of operations. In accordance with the Company’s Topic 842 transition discussed above, no prior period amounts were changed. For purposes of comparison, the following tables show how the balances as of December 31, 2018 and for the year ended December 31, 2018 would have changed if the effects of adopting Topic 842 had been applied to those balances (in thousands): December 31, 2018 December 31, 2019 As Reported Adjustments As Adjusted As Reported Solar energy systems, net $ 1,938,874 $ (388,087 ) $ 1,550,787 $ 1,759,861 Other non-current assets, net 28,090 388,087 416,177 680,062 Year Ended December 31, 2018 2019 As Reported Adjustments As Adjusted As Reported Cost of revenue—customer agreements and incentives $ 164,920 $ (18,164 ) $ 146,756 $ 186,325 Cost of revenue—solar energy system and product sales 83,375 (19,060 ) 64,315 72,221 Total cost of revenue 248,295 (37,224 ) 211,071 258,546 Gross profit 42,026 37,224 79,250 82,495 Sales and marketing 58,950 37,224 96,174 151,194 Total operating expenses 154,520 37,224 191,744 271,059 Solar Energy Systems, Net The Company sells energy to customers through PPAs or leases solar energy systems to customers through Solar Leases. The solar energy systems installed at customers’ homes are stated at cost, less accumulated depreciation and amortization. The Company also sells solar energy systems to customers through System Sales. Systems that are sold to customers are not part of solar energy systems, net. Solar energy systems, net is composed of system equipment costs related to solar energy systems subject to PPAs or Solar Leases. Prior to the implementation of Topic 842 on January 1, 2019, solar energy systems, net also included capitalized initial direct costs. Subsequent to the adoption of Topic 842, previously capitalized initial direct costs and related accumulated amortization were removed from solar energy systems, net and recorded in other non-current assets, net as incremental costs of obtaining contracts. See “—Leases” above for additional information on the effects of adopting Topic 842. System equipment costs include components such as solar panels, inverters, racking systems and other electrical equipment, as well as costs for design and installation activities once a long-term customer contract has been executed. System equipment costs are capitalized and recorded within solar energy systems, net. System equipment costs are depreciated using the straight-line method over 30 years, which is the estimated useful life of the equipment. System equipment costs are depreciated once the respective systems have been installed, interconnected to the power grid and received permission to operate. The determination of the useful lives of assets included within solar energy systems involves significant management judgment. As of December 31, 2019 and 2018, the Company had recorded costs of $1,965.2 million and $2,134.8 million in solar energy systems, of which $1,873.2 million and $1,999.3 million related to systems that had been interconnected to the power grid, with accumulated depreciation and amortization of $205.3 million and $195.9 million. Property and Equipment, Net The Company’s property and equipment is stated at cost less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method over the estimated useful lives of the assets. The right-of-use assets for vehicles leased under finance leases are amortized over the life of the lease term, which is typically three to four years. The estimated useful lives of computer equipment, furniture, fixtures and purchased software are three years. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful lives of the assets. The estimated useful lives of leasehold improvements currently range from one to 12 years. Repairs and maintenance costs are expensed as incurred. Major renewals and improvements that extend the useful lives of existing assets would be capitalized and depreciated over their estimated useful lives. Intangible Assets The Company capitalizes costs incurred in the development of internal-use software during the application development stage. Costs related to preliminary project activities and post-implementation activities are expensed as incurred. Internal-use software is amortized on a straight-line basis over its estimated useful life, which is typically three to five years. The Company tests these assets for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. The Company recorded amortization for internal-use software of $0.1 million and $0.4 million for the years ended December 31, 2019 and 2018. The Company adopted ASU 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract Other finite-lived intangible assets, which consist of developed technology acquired in business combinations and trademarks/trade names are initially recorded at fair value and presented net of accumulated amortization. These intangible assets are amortized on a straight-line basis over their estimated useful lives. The Company amortizes trademarks/trade names over 10 years and developed technology over eight years. See Note 8—Intangible Assets. Impairment of Long-Lived Assets The carrying amounts of the Company’s long-lived assets, including solar energy systems, property and equipment and finite-lived intangible assets are periodically reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable or that the useful life is shorter than originally estimated. Factors that the Company considers in deciding when to perform an impairment review include significant negative industry or economic trends, and significant changes or planned changes in the Company’s use of the assets. Recoverability of these assets is measured by comparison of the carrying amount of each asset to the future undiscounted cash flows the asset is expected to generate over its remaining life. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. If the useful life is shorter than originally estimated, the Company amortizes the remaining carrying value over the new shorter useful life. Other Non-Current Assets See Note 7—Other Non-Current Assets for the components of other non-current assets. Capitalized costs to obtain contracts were previously considered initial direct costs and recorded within solar energy systems, net prior to the adoption of Topic 842. See “—Leases” above. Capitalized costs to obtain contracts consist of sales commissions and other customer acquisition expenses and are amortized to sales and marketing expense over the period of benefit, which is most commonly 20 years. Prepaid inventory represents payments for solar energy system components that were not delivered until the subsequent year. Operating lease right-of-use assets represent contractual rights to use assets such as offices, warehouses and related equipment in lease arrangements classified as operating leases. See Note 12—Leases. Sales incentives represent cash payments made by the Company to customers in order to finalize long-term customer contracts. Debt issuance costs represent costs incurred in connection with obtaining revolving debt financings and are deferred and amortized utilizing the straight-line method, which approximates the effective-interest method, over the term of the related financing. The Company has acquired insurance policies to mitigate the risk of ITC recapture. The insurance premiums are being amortized on a straight-line basis over the policy period. The Company provides advance payments of compensation to direct-sales personnel under certain circumstances. The advance is repaid as a reduction of the direct-sales personnel’s future compensation. The Company has established an allowance related to advances to direct-sales personnel who have terminated their employment agreement with the Company. These are non-interest-bearing advances. For Solar Lease agreements, the Company recognizes revenue on a straight-line basis over the lease term and records an asset that represents future customer payments expected to be received. Distributions Payable to Non-Controlling Interests and Redeemable Non-Controlling Interests As discussed in Note 14—Investment Funds, the Company and fund investors have formed various investment funds that the Company consolidates as the Company has determined that it is the primary beneficiary in the operational VIEs in which it has an equity interest. These VIEs are required to pay cumulative cash distributions to their respective fund investors. The Company accrues amounts payable to fund investors in distributions payable to non-controlling interests and redeemable non-controlling interests. Deferred Revenue Deferred revenue primarily includes cash received in advance of revenue recognition related to System Sales and rebate incentives. A portion of the cash received for System Sales is attributable to administrative services and is deferred over the period that the administrative services are provided. The majority of the cash received for System Sales is deferred until the solar energy systems are interconnected to the local power grids and receive permission to operate. Rebate incentives are received from utility companies and various government agencies and are recognized as revenue over the related customer contract term, which is most commonly 20 years. See “ — Workmanship Accruals and Warranties The Company typically warrants solar energy systems sold to customers for periods of one to ten years against defects in design and workmanship, and for periods of one to ten years that installations will remain watertight. The manufacturers’ warranties on the solar energy system components, which are typically passed through to the customers, have typical product warranty periods of 10 to 20 years and a limited performance warranty period of 25 years. The Company warrants its photovoltaic installation devices for six months to one year against defects in materials or installation workmanship. The Company generally assesses a loss contingency accrual for installation workmanship and provides for the estimated cost at the time that installation is completed. The Company assesses the workmanship accruals regularly and adjusts the amounts as necessary based on actual experience and changes in future estimates. The current portion of this accrual is recorded as a component of accrued and other current liabilities and was $4.2 million and $2.6 million as of December 31, 2019 and 2018. The non-current portion of this accrual is recorded as a component of other non-current liabilities and was $6.1 million and $3.9 million as of December 31, 2019 and 2018. Derivative Financial Instruments The Company maintains interest rate swaps as required by the terms of its debt agreements. See Note 11—Debt Obligations. The interest rate swaps related to the Solar Asset Backed Notes, Series 2018-2 are designated as cash flow hedges. Changes in the fair value of these cash flow hedges are recorded in other comprehensive loss (“OCI”) and will subsequently be reclassified to interest expense over the life of the related debt facility as interest payments are made. As interest payments for the associated debt agreement and derivatives are recognized, the Company includes the effect of these payments in cash flows from operating activities within the consolidated statements of cash flows. The interest rate swaps related to the Warehouse Facility are not designated as hedge instruments and any changes in fair value are accounted for in other expense (income), net. Derivative instruments may be offset under their master netting arrangements. See Note 13—Derivative Financial Instruments. Comprehensive Loss Comprehensive loss includes unrealized losses on the Company’s cash flow hedges and interest on derivatives recognized into earnings for the years ended December 31, 2019 and 2018. Revenue Recognition In accordance with Topic 606, the Company recognizes revenue according to the following steps: (1) identification of the contract with a customer, (2) identification of the performance obligations in the contract, (3) determination of the transaction price, (4) allocation of the transaction price to the performance obligations in the contract and (5) recognition of revenue when, or as, the Company satisfies a performance obligation. The Company’s revenue is composed of customer agreements and incentives, and solar energy system and product sales as captioned in the consolidated statements of operations. Customer agreements and incentives revenue includes PPA and Solar Lease revenue, solar renewable energy certificates (“SRECs”) sales and rebate incentives. Solar energy system and product sales revenue includes System Sales, which may include structural upgrades in sales contracts and SREC sales related to sold systems, and the sale of photovoltaic installation products. Revenue is recorded net of any sales tax collected. Customer Agreements and Incentives Revenue The Company enters into PPAs with residential customers, under which the customer agrees to purchase all of the power generated by the solar energy system for the term of the contract, which is most commonly 20 years. The agreement includes a fixed price per kilowatt hour with a fixed annual price escalation percentage. Customers have not historically been charged for installation or activation of the solar energy system. For all PPAs, the Company assesses the probability of collectability on a customer-by-customer basis through a credit review process that evaluates their financial condition and ability to pay. PPA revenue is recognized based on the actual amount of power generated at rates specified under the contracts. The Company also offers solar energy systems to customers pursuant to Solar Leases in certain markets. The customer agreements are structured as Solar Leases due to local regulations that can be read to prohibit the sale of electricity pursuant to the Company’s standard PPA. Pursuant to Solar Leases, the customers’ monthly payments are a pre-determined amount calculated based on the expected solar energy generation by the system and typically have included an annual fixed percentage price escalation over the period of the contracts, which is most commonly 20 years, though some markets offer Solar Leases with no annual price escalation. Revenue from Solar Leases is recognized on a straight-line basis over the contractual term. The Company records a straight-line Solar Lease asset in other non-current assets, net, which represents revenue recognized in advance of customer payments. The Company provides its Solar Lease customers a performance guarantee, under which the Company agrees to refund certain payments at the end of each year to the customer if the solar energy system does not meet a guaranteed production level in the prior 12-month period. The guaranteed production levels have varying terms. Solar energy performance guarantee liabilities were $0.5 million and $0.2 million as of December 31, 2019 and 2018. Solar energy performance guarantees are recognized as contra-revenue in the period in which

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. The following tables set forth the fair value of the Company’s financial assets and liabilities included on the consolidated balance sheets measured on a recurring basis by level within the fair value hierarchy (in thousands): December 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets Interest rate swaps $ — $ 3,245 $ — $ 3,245 Financial Liabilities Interest rate swaps $ — $ 28,070 $ — $ 28,070 December 31, 2018 Level 1 Level 2 Level 3 Total Financial Assets Interest rate swaps $ — $ 130 $ — $ 130 Financial Liabilities Interest rate swaps $ — $ 11,146 $ — $ 11,146 The interest rate swaps (Level 2) were valued using a discounted cash flow model which incorporates an assessment of the risk of non-performance by the interest rate swap counterparties and the Company. The valuation model uses various observable inputs including contractual terms, interest rate curves, credit spreads and measures of volatility. Financial assets as of December 31, 2019 include interest rate swaps for the Warehouse Facility, which are not designated as hedges. Financial liabilities as of December 31, 2019 include interest rate swaps for the Solar Asset Backed Notes, Series 2018-2, which are designated as hedges. Financial assets as of December 31, 2018 primarily related to interest rate swaps for the Aggregation Facility, which were not designated as hedges. Financial liabilities as of December 31, 2018 included interest rate swaps for the Aggregation Facility, which were not designated as hedges, and interest rate swaps for the Solar Asset Backed Notes, Series 2018-2, which are designated as hedges. See Note 11—Debt Obligations for additional details about these debt instruments. The carrying values and fair values of the Company’s long-term debt were as follows (in thousands): December 31, 2019 December 31, 2018 Carrying Value Fair Value Carrying Value Fair Value Floating-rate long-term debt $ 894,907 $ 894,907 $ 587,358 $ 587,358 Fixed-rate long-term debt 629,908 702,895 653,031 673,917 Subtotal long-term debt 1,524,815 $ 1,597,802 1,240,389 $ 1,261,275 Unamortized debt issuance costs (25,154 ) (24,952 ) Total long-term debt $ 1,499,661 $ 1,215,437 The Company’s outstanding balance of long-term debt is carried at cost net of unamortized debt issuance costs, where applicable. See Note 11—Debt Obligations. The Company estimated the fair values of its floating-rate debt facilities (Level 2) to approximate their carrying values as interest accrues at floating rates based on market rates. The Company’s fixed-rate debt facilities (Level 2) were valued using quoted prices for the fixed rate debt facilities that are publicly traded, or quoted prices for corporate debt with similar terms for debt facilities that are not publicly traded.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Inventories	4. Inventories consisted of the following (in thousands): December 31, December 31, 2019 2018 Solar energy systems held for sale $ 19,892 $ 12,321 Photovoltaic installation products 684 936 Total inventories $ 20,576 $ 13,257 Solar energy systems held for sale are solar energy systems under construction that have yet to be interconnected to the power grid and that will be sold to customers. Solar energy systems held for sale are stated at the lower of cost, on a FIFO basis, or net realizable value. Photovoltaic installation products are stated at the lower of cost, on an average cost basis, or net realizable value.

Solar Energy Systems

Solar Energy Systems	12 Months Ended
	Dec. 31, 2019
Solar Energy Systems Disclosure [Abstract]
Solar Energy Systems	5. Solar energy systems, net consisted of the following (in thousands): December 31, December 31, 2019 2018 System equipment costs $ 1,926,809 $ 1,667,440 Initial direct costs related to solar energy systems — 435,084 1,926,809 2,102,524 Less: Accumulated depreciation and amortization (205,338 ) (195,890 ) 1,721,471 1,906,634 Solar energy system inventory 38,390 32,240 Solar energy systems, net $ 1,759,861 $ 1,938,874 Solar energy system inventory represents the solar components and materials used in the installation of solar energy systems prior to being installed on customers’ roofs. As such, no depreciation is recorded related to this line item. The Company recorded depreciation expense related to solar energy systems of $56.4 million for the year ended December 31, 2019 and depreciation and amortization expense related to solar energy systems of $66.3 million for the year ended December 31, 2018. The Company did not record any initial direct costs or amortization of initial direct costs related to solar energy systems in 2019 due to the adoption of Topic 842. See Note 2—Summary of Significant Accounting Policies.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Property and Equipment	6. Property and equipment, net consisted of the following (in thousands): Estimated December 31, December 31, Useful Lives 2019 2018 Leasehold improvements 1-12 years $ 10,458 $ 10,560 Vehicles acquired under finance leases 3-4 years 10,280 6,907 Furniture and computer and other equipment 3-5 years 5,021 3,816 25,759 21,283 Less: Accumulated depreciation and amortization (8,259 ) (10,553 ) Property and equipment, net $ 17,500 $ 10,730 The Company recorded depreciation and amortization expense related to property and equipment of $2.8 million and $4.8 million for the years ended December 31, 2019 and 2018.

Other Non-Current Assets

Other Non-Current Assets	12 Months Ended
	Dec. 31, 2019
Other Assets Noncurrent Disclosure [Abstract]
Other Non-Current Assets	7. Other non-current assets consisted of the following (in thousands): December 31, December 31, 2019 2018 Costs to obtain contracts $ 615,385 $ — Accumulated amortization of costs to obtain contracts (70,170 ) — Prepaid inventory 50,104 — Operating lease right-of-use assets 39,118 — Sales incentives 10,008 8,588 Debt issuance costs 9,936 2,415 Prepaid insurance 6,541 6,890 Advances receivable from sales professionals 6,395 5,109 Solar Lease straight-line asset 5,722 3,402 Other non-current assets 7,023 1,686 Total other non-current assets $ 680,062 $ 28,090 The Company recorded amortization of costs to obtain contracts of $23.2 million for the year ended December 31, 2019 due to the adoption of Topic 842. See Note 2—Summary of Significant Accounting Policies. Costs to obtain contracts are amortized over the period of benefit, which is typically 20 years.

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets	8. Net intangible assets are included in other non-current assets, net and consisted of the following (in thousands): December 31, December 31, 2019 2018 Cost: Internal-use software $ 2,596 $ 1,020 Developed technology 522 522 Trademarks/trade names 201 201 Total carrying value 3,319 1,743 Accumulated amortization: Internal-use software (105 ) (781 ) Developed technology (393 ) (324 ) Trademarks/trade names (119 ) (99 ) Total accumulated amortization (617 ) (1,204 ) Total intangible assets, net $ 2,702 $ 539 The Company recorded amortization expense of $0.2 million and $0.5 million for the years ended December 31, 2019 and 2018, which is included within general and administrative expense on the consolidated statements of operations. Internal-use software includes approximately $2.4 million related to capitalized implementation costs incurred during the implementation of the Company’s enterprise resource planning system, which is a cloud computing arrangement that is a service contract. The capitalized implementation costs are an intangible asset that is in process and not yet subject to amortization. The Company will begin to amortize this intangible asset over the length of the service contract, which is five years, when it is placed into service, which was January 2020. As of December 31, 2019, expected amortization expense for the unamortized intangible assets was as follows (in thousands): Years Ending December 31, 2020 $ 635 2021 605 2022 495 2023 492 2024 475 Thereafter — Total $ 2,702

Accrued Compensation

Accrued Compensation	12 Months Ended
	Dec. 31, 2019
Accrued Compensation Disclosure [Abstract]
Accrued Compensation	9. Accrued compensation consisted of the following (in thousands): December 31, December 31, 2019 2018 Accrued payroll $ 18,633 $ 16,352 Accrued commissions 15,516 9,168 Total accrued compensation $ 34,149 $ 25,520

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	12 Months Ended
	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued and Other Current Liabilities	10. Accrued and other current liabilities consisted of the following (in thousands): December 31, December 31, 2019 2018 Accrued unused commitment fees and interest $ 16,995 $ 14,102 Litigation settlement 12,780 100 Current portion of operating lease liabilities 8,436 — Accrued workers' compensation 7,166 4,033 Accrued professional fees 5,546 6,150 Current portion of lease pass-through financing obligation 5,147 5,038 Accrued inventory 4,667 4,380 Sales, use and property taxes payable 4,321 3,132 Workmanship accrual 4,217 2,630 External customer experience services 1,984 — Other accrued expenses 7,280 3,295 Total accrued and other current liabilities $ 78,539 $ 42,860

Debt Obligations

Debt Obligations	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt Obligations	11. Debt obligations consisted of the following as of December 31, 2019 (in thousands, except interest rates): Principal Unamortized Debt Unused Borrowings Issuance Costs Net Carrying Value Borrowing Interest Maturity Outstanding Current Long-term Current Long-term Capacity Rate Date Solar asset backed notes, Series 2018-1 (1) $ 448,277 $ (69 ) $ (8,414 ) $ 3,639 $ 436,155 $ — 5.1 % October 2028 Solar asset backed notes, Series 2018-2 (2)(3) 338,294 (5 ) (6,133 ) 1,245 330,911 — 5.5 August 2023 2017 Term loan facility 180,365 (164 ) (4,235 ) 7,882 168,084 — 6.0 January 2035 2018 Forward flow loan facility 124,800 (99 ) (3,083 ) 3,622 117,996 — 4.7 November 2039 2019 Forward flow loan facility 82,813 — (2,857 ) — 79,956 67,187 4.7 (4) Credit agreement 1,266 (2 ) (93 ) 17 1,154 — 6.5 February 2023 Revolving lines of credit (5) Warehouse facility 250,000 — — — 250,000 75,000 4.3 August 2023 Asset Financing Facility (6) 99,000 — — — 99,000 81,362 5.2 June 2023 Total debt $ 1,524,815 $ (339 ) $ (24,815 ) $ 16,405 $ 1,483,256 $ 223,549 Debt obligations consisted of the following as of December 31, 2018 (in thousands, except interest rates): Principal Unamortized Debt Unused Borrowings Issuance Costs Net Carrying Value Borrowing Interest Maturity Outstanding Current Long-term Current Long-term Capacity Rate Date Solar asset backed notes, Series 2018-1 (1) $ 462,826 $ (74 ) $ (9,172 ) $ 3,655 $ 449,925 $ — 5.1 % October 2028 Solar asset backed notes, Series 2018-2 (2)(3) 342,833 (6 ) (7,388 ) 294 335,145 — 5.4 August 2023 2017 Term loan facility 188,922 (170 ) (4,614 ) 6,679 177,459 — 6.0 January 2035 2018 Forward flow loan facility 58,425 (43 ) (3,365 ) 1,512 53,505 71,575 5.2 November 2039 Credit agreement 1,283 (2 ) (118 ) 15 1,148 — 6.5 February 2023 Revolving lines of credit (5) Aggregation facility 50,000 — — — 50,000 325,000 5.7 September 2020 Working capital facility (6) 136,100 — — — 136,100 — 5.6 March 2020 Total debt $ 1,240,389 $ (295 ) $ (24,657 ) $ 12,155 $ 1,203,282 $ 396,575 (1) The interest rate disclosed in the table above is a weighted-average rate. The Series 2018-1 Notes are composed of Class A and Class B Notes. Class A Notes accrue interest at 4.73%. Class B Notes accrue interest at 7.37%. (2) The Series 2018-2 Notes are composed of Class A and Class B Notes. Class B Notes accrue interest at a rate of LIBOR plus 4.75%. Class A Notes accrue interest at a variable spread over LIBOR that results in a weighted average spread for all 2018-2 Notes of 2.95%. (3) The interest rate of this facility is partially hedged to an effective interest rate of 6.0% for $323.6 million of the principal borrowings. See Note 13—Derivative Financial Instruments. (4) The maturity date for this facility is 20 years from the end date of the borrowing availability period when all borrowings are aggregated into one term loan, which will be no later than November 20, 2020. (5) Revolving lines of credit are not presented net of unamortized debt issuance costs. (6) Facility is recourse debt, which refers to debt that is collateralized by the Company’s general assets. All of the Company’s other debt obligations are non-recourse, which refers to debt that is only collateralized by specified assets or subsidiaries of the Company. The Company’s debt facilities include customary events of default, conditions to borrowing and covenants, including covenants that restrict, subject to certain exceptions, the Company’s ability to incur indebtedness, incur liens, make investments, make fundamental changes to their business, dispose of assets, make certain types of restricted payments or enter into certain related party transactions. Additionally, the Company is required to maintain certain financial measurements and interest rate swaps for certain debt facilities. These restrictions do not impact the Company’s ability to enter into investment funds, including those that are similar to those entered into previously. The Company’s debt facilities are secured by net cash flows from long-term customer contracts. The Company was in compliance with all debt covenants as of December 31, 2019. Solar Asset Backed Notes, Series 2018-1 In June 2018, a wholly owned subsidiary of the Company issued an aggregate principal amount of $400.0 million of Solar Asset Backed Notes, Series 2018-1, Class A (the “2018-1 Class A Notes”) and an aggregate principal amount of $66.0 million of Solar Asset Backed Notes, Series 2018-1, Class B (the “2018-1 Class B Notes”) and together with the 2018-1 Class A Notes, (the “2018-1 Notes”). The 2018-1 Class A Notes accrue interest at a fixed rate of 4.73% and have an anticipated repayment date of October 30, 2028. The 2018-1 Class B Notes accrue interest at a fixed rate of 7.37% and have an anticipated repayment date of October 30, 2028. In addition to customary events of default and covenants, the 2018-1 Notes are subject to unscheduled prepayment events that generally are customary in nature for solar securitizations of this type, including (1) asset coverage ratios falling below certain levels, (2) a debt service coverage ratio falling below certain levels, (3) the failure to maintain insurance, and (4) the failure to repay the notes in full prior to the anticipated repayment date for such class of notes. The occurrence of an unscheduled prepayment event or an event of default could result in the more rapid repayment of the 2018-1 Notes, and the occurrence of an event of default could, in certain instances, result in the liquidation of the collateral securing the 2018-1 Notes. The 2018-1 Notes are secured by, and payable solely from the cash flow generated by the membership interests in certain indirectly owned subsidiaries of the Company, each of which subsidiaries is the managing member of a project company that owns a pool of photovoltaic systems and related Solar Leases and PPAs and ancillary rights and agreements that were originated by a wholly owned subsidiary of the Company. As of December 31, 2019, the Company had $16.3 million in required reserves outstanding in collateral accounts with the administrative agent, which are included in restricted cash and cash equivalents. Solar Asset Backed Notes, Series 2018-2 In June 2018, a wholly owned subsidiary of the Company issued an aggregate principal amount of $296.0 million of Solar Asset Backed Notes, Series 2018-2, Class A (the “2018-2 Class A Notes”) and an aggregate principal amount of $49.0 million of Solar Asset Backed Notes, Series 2018-2, Class B (the “2018-2 Class B Notes”) and together with the 2018-2 Class A Notes, (the “2018-2 Notes”). The 2018-2 Class A Notes accrue interest at a variable spread over the London Interbank Offered Rate (“LIBOR”) that is intended to result in a weighted average spread for all 2018-2 Notes of 2.95%. The 2018-2 Class B Notes accrue interest at a spread over LIBOR of 4.75% or, if no 2018-2 Class A Notes are outstanding, 2.95%. The Company entered into an interest rate swap concurrent with the issuance of the 2018-2 Notes that results in an implied all-in interest rate of approximately 5.95%. See Note 13—Derivative Financial Instruments. The 2018-2 Notes have a stated maturity of August 29, 2023. The 2018-2 Notes have the same events of default, covenants and unscheduled prepayment events as the 2018-1 Notes. In addition, the 2018-2 Notes are subject to unscheduled prepayment events relating to certain change of control events and certain liquidity requirements. As of December 31, 2019, the Company had $25.4 million in required reserves outstanding in collateral accounts with the administrative agent, which are included in restricted cash and cash equivalents. 2016 Term Loan Facility In June 2018, the Company used proceeds from the issuance of the 2018-1 Notes and 2018-2 Notes to pay off the outstanding balance of $282.3 million on the credit facility entered into by a wholly owned subsidiary of the Company in August 2016 (the “2016 Term Loan Facility”) and terminated the credit agreement. At termination, the outstanding balance was composed of $281.8 million of principal and $0.5 million of accrued interest. The termination of the 2016 Term Loan Facility was accounted for as a debt extinguishment. As such, the remaining $6.9 million of unamortized debt issuance costs related to the 2016 Term Loan Facility were recognized in interest expense during the year ended December 31, 2018. There was no prepayment fee associated with the termination of the 2016 Term Loan Facility. Subordinated HoldCo Facility In June 2018, the Company used proceeds from the issuance of the 2018-1 Notes and 2018-2 Notes to pay off the outstanding balance of $206.4 million on the credit facility entered into by a wholly owned subsidiary of the Company in March 2016 (the “Subordinated HoldCo Facility”) and terminated the financing agreement. At termination, the outstanding balance was composed of $196.6 million of principal, $3.9 million of accrued interest, and a prepayment fee of $5.9 million, which was calculated as 3.0% of the outstanding principal balance. The termination of the Subordinated HoldCo Facility was accounted for as a debt extinguishment. As such, the remaining $2.9 million of unamortized debt issuance costs related to the Subordinated HoldCo Facility were recognized in interest expense during the year ended December 31, 2018. The prepayment fee of $5.9 million was also recognized in interest expense during the year ended December 31, 2018. 2017 Term Loan Facility In January 2017, a wholly owned subsidiary of the Company entered into a long-term fixed rate credit agreement (the “2017 Term Loan Facility”). Interest on borrowings accrues at an annual fixed rate equal to 6.0% and is payable in arrears. Certain principal payments are due on a quarterly basis, subject to the occurrence of certain events. As of December 31, 2019, the Company had $20.4 million in required reserves 2018 Forward Flow Loan Facility In August 2018, a subsidiary that is indirectly owned by the Company together with investors, entered into a loan agreement (the “2018 Forward Flow Loan Facility”) pursuant to which the Company borrowed an aggregate principal amount of $124.8 million. The Company was permitted to make multiple borrowings under the 2018 Forward Flow Loan Facility during the availability period. In November 2019, all outstanding loans under the 2018 Forward Flow Loan Facility were aggregated into a single term loan with a maturity date of November 20, 2039. Interest on the aggregated term loan accrues at an annual fixed rate of 4.7%. The interest rate of the aggregated term loan is a blended rate based on weighted draws during the availability period. Upon the occurrence of certain events, the Company will be required to make prepayments of the loans, including payment of a make-whole amount in certain circumstances. As of December 31, 2019, the Company had $6.4 million in required reserves outstanding in collateral accounts with the administrative agent, which were included in restricted cash and cash equivalents. 2019 Forward Flow Loan Facility In May 2019, a subsidiary that is indirectly owned by the Company together with investors, entered into a loan agreement (the “2019 Forward Flow Loan Facility”) pursuant to which the Company may borrow up to an aggregate principal amount of $150.0 million. The Company may make multiple borrowings under the 2019 Forward Flow Loan Facility during the availability period, which will continue no later than November 20, 2020. After the availability period, all outstanding loans under the 2019 Forward Flow Loan Facility will be aggregated into a single term loan with a maturity date 20 years after the date of aggregation. On any anniversary of the date of aggregation occurring from and after the sixth such anniversary, upon notice to the lenders, the Company may borrow additional loans under the 2019 Forward Flow Loan Facility if the Company is projected to have sufficient net cash flow to service such additional debt. If any lender declines to fund such additional loans, the Company will have the right to prepay outstanding loans from such lender in an amount equal to 102.5% of such loans, plus accrued and unpaid interest, without any make-whole amount. Interest on each loan will accrue at an annual rate equal to the greater of (a) 4.70% and (b) the U.S. Treasury rate for the weighted-average life of such loan, plus an applicable margin equal to 2.35%. Scheduled principal payments are due on a quarterly basis, at the end of January, April, July and October of each year. Upon the occurrence of certain events, the Company will be required to make prepayments of the loans, including payment of a make-whole amount in certain circumstances. As of December 31, 2019, the Company had $2.5 million in required reserves outstanding in collateral accounts with the administrative agent, which were included in restricted cash and cash equivalents. Credit Agreement In February 2016, a wholly owned subsidiary of the Company entered into a fixed rate credit agreement (the “Credit Agreement”). Principal and interest payments under the Credit Agreement are paid quarterly over the term of the loan. Interest accrues on borrowings at a fixed rate of 6.50%. Warehouse Facility In August 2019, a wholly owned subsidiary of the Company entered into a floating rate revolving warehouse facility (the “Warehouse Facility”) pursuant to which it may borrow up to an aggregate principal amount of $325.0 million, expandable up to $400.0 million, from certain financial institutions for which Bank of America, N.A. is acting as administrative agent and collateral agent. During the period in which the Company may make borrowings under the Warehouse Facility, which is currently anticipated to continue until August 2022, interest on borrowings accrues at an annual rate equal to the applicable adjusted LIBOR rate plus 2.375%. Thereafter, interest will accrue at an annual rate equal to the applicable adjusted LIBOR rate plus 3.375%. In addition, the Company is required to maintain interest rate hedging arrangements such that not less than 90% of the aggregate expected amortization profile of all outstanding revolving advances is subject to a fixed interest rate or other interest rate protection. Initially, subject to the terms of the Warehouse Facility, only interest payments are due on a quarterly basis, through the availability period, and then certain principal and interest payments may be due. These payments will occur on the 15 th Aggregation Facility In August 2019, the Company used proceeds from the Warehouse Facility to pay off the outstanding balance of $121.4 million on the aggregation credit facility entered into by a wholly owned subsidiary of the Company in September 2014 (as amended, the “Aggregation Facility”) and terminated the facility. At termination, the outstanding balance was composed of $115.0 million of principal, $0.6 million of accrued interest and $5.8 million to settle related interest rate swaps. The termination of the Aggregation Facility was accounted for as a modification of a line of credit. Of the remaining $3.6 million of unamortized debt issuance costs, $2.5 million was recognized in interest expense during the year ended December 31, 2019 and $1.1 million was deferred and will be amortized over the term of the Warehouse Facility. Asset Financing Facility In December 2019, a wholly owned subsidiary of the Company entered into a loan and security agreement (the “Asset Financing Facility”) with certain financial institutions for which Bank of America, N.A. is acting as administrative agent and collateral agent, under which the Company may incur up to an aggregate principal amount of $200.0 million in revolver borrowings. The Asset Financing Facility matures in June 2023. In addition to the outstanding borrowings as of December 31, 2019, the Company had established letters of credit under the Asset Financing Facility for up to $19.6 million related to insurance and retail contracts. Borrowings under the Asset Financing Facility may be designated as base rate loans or LIBOR loans, subject to certain terms and conditions. Base rate loans accrue interest at a rate per year equal to 2.25% plus the highest of (i) the federal funds rate plus 0.5%, (ii) Bank of America, N.A.’s published “prime rate,” and (iii) LIBOR rate plus 1.0%, subject to a 0.0% floor. LIBOR loans accrue interest at a rate per annum equal to 3.25% plus the fluctuating rate of interest equal to LIBOR or a comparable successor rate approved by the administrative agent, subject to a 0.0% floor. In addition to customary covenants for this type of facility, the Company is subject to a financial covenant and is required to have unencumbered cash and cash equivalents at the end of each fiscal quarter of at least the greater of (i) $30.0 million and (ii) the amount of unencumbered liquidity to be maintained by the Company in accordance with any loan documents governing its recourse debt facilities. As of December 31, 2019, the Company was in compliance with such covenants. Additionally, as of December 31, 2019, the Company had $2.6 million in required reserves outstanding in collateral accounts with the administrative agent, which were included in restricted cash and cash equivalents. Working Capital Facility In December 2019 , the Company used proceeds from the Asset Financing Facility and existing cash balances to pay off the outstanding balance of $130.8 million on the revolving credit agreement entered into by a wholly owned subsidiary of the Company in March 2015 (the “Working Capital Facility”) and terminated the facility. At termination, the outstanding balance was composed of $130.3 million of principal and $0.5 million of accrued interest and fees. The termination of the Working Capital Facility was accounted for as a modification of a line of credit. The remaining $0.2 million of unamortized debt issuance costs was recognized in interest expense in December 2019. Scheduled Maturities of Debt The scheduled maturities of debt as of December 31, 2019 are as follows (in thousands): 2020 $ 14,425 2021 15,803 2022 21,065 2023 704,801 2024 28,908 Thereafter 739,813 Total $ 1,524,815

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Lessee Disclosure [Abstract]
Leases	12. The Company is the lessee in all of its lease arrangements. The Company did not enter into any leases with related parties during the presented periods. The Company makes significant assumptions and judgments when assessing contracts for lease components, determining lease classifications and calculating right-of-use asset and lease liability values. These assumptions and judgments may include the useful lives and fair values of the leased assets, the implicit rate underlying the Company’s leases, the Company’s incremental borrowing rate or the Company’s intent to exercise or not exercise options available in lease contracts. Lease costs and other information consisted of the following (in thousands, except terms and rates): Year Ended December 31, 2019 Lease cost Finance lease cost: Amortization of right-of-use assets $ 1,758 Interest on lease liabilities 326 Operating lease cost 11,329 Short-term lease cost 2,069 Total lease cost $ 15,482 Other information Finance leases: Operating cash outflows from finance leases $ 326 Financing cash outflows from finance leases $ 1,480 Right-of-use assets obtained in exchange for new finance lease liabilities $ 9,482 Weighted-average remaining lease term - finance leases (in years) 3.6 Weighted-average discount rate - finance leases 7.2 % Operating leases: Operating cash outflows from operating leases $ 11,460 Right-of-use assets obtained in exchange for new operating lease liabilities $ 12,217 Weighted-average remaining lease term - operating leases (in years) 8.9 Weighted-average discount rate - operating leases 8.0 % Finance Leases The Company’s finance leases relate to fleet vehicles. All of the Company’s fleet vehicles are leased pursuant to master lease agreements for a period of three to four years. The master lease agreements allow for the Company to extend fleet vehicle leases on a month-to-month basis. For administrative convenience, the Company will often commit to extension periods of up to one year. As the extensions are not always utilized and are not contractually bound to a specific period of time, these extensions are not included in the initial right-of-use assets and lease liabilities. Instead, these extensions are treated as new leases. The master lease agreements stipulate minimum residual value guarantees that are not typically recognized as part of the Company’s right-of use assets and lease liabilities as these residual value guarantees are not probable of being owed. The rates implicit in the Company’s fleet vehicle finance leases are determinable, and the Company uses those rates to calculate the present value of its lease liabilities related to fleet vehicles. Future minimum lease payments for the Company’s finance leases as of December 31, 2019 were as follows (in thousands): 2020 $ 2,806 2021 2,775 2022 2,649 2023 1,607 2024 — Thereafter — Total minimum lease payments 9,837 Less: interest 1,120 Present value of finance lease obligations 8,717 Less: current portion 2,274 Long-term portion $ 6,443 Operating Leases The Company has entered into lease agreements for offices, warehouses and related equipment located in states in which the Company conducts operations. The Company’s corporate office lease was amended in February 2019 to extend the term by an additional three years, for a total lease term of 15 years. The corporate office lease includes options to extend the lease term for two additional periods of five years each. The Company’s warehouse lease agreements range from a term of one to nine years, including exercised options to extend, with five years being the most common lease term. The warehouse lease agreements typically include options to extend the lease term. The Company’s operating lease agreements typically do not include purchase options. The Company includes lease extension options in the right-of-use asset and lease liability when the Company is reasonably certain it will exercise the options. The Company’s equipment lease agreements range from three to five years. The rates implicit in the Company’s operating leases are not readily determinable. As such, the Company uses its incremental borrowing rate to calculate the present value of its operating lease liabilities. The Company estimates its incremental borrowing rate as the interest rate that the Company would have to pay to borrow on a collateralized basis over a similar term an amount equal to the lease payments in a similar economic environment. To estimate the incremental borrowing rate, an estimated credit rating is developed for the Company using various financial metrics in statistical models. A benchmark yield curve for corporate bonds matching the estimated credit rating is then used to develop an incremental borrowing rate curve for the Company. The Company has entered into a lease for approximately 32,000 square feet of office space in a newly constructed building adjacent to the Company’s corporate headquarters. The Company did not have any significant involvement with the construction or design of the building. The lease commenced subsequent to December 31, 2019 and as such, there was no right-of-use asset or lease liability related to this lease recorded for year ended December 31, 2019. The initial term of the lease is approximately 11.5 years, with two options to extend the lease for five years each. The Company expects to make total rent payments of approximately $11.2 million over the initial term. Additionally, the Company entered into a lease for approximately 40,000 square feet in an existing office building in the same general vicinity as its corporate headquarters. The lease is expected to commence in the first quarter of 2020 and as such, there was no right-of-use asset or lease liability related to this lease recorded for the year ended December 31, 2019. The initial term of the lease is approximately 5.5 years, with two options to extend the lease for two years each. The Company expects to make total rent payments of approximately $4.6 million over the initial term. For all non-cancellable lease arrangements, there are no bargain renewal options, penalties for failure to renew, or any guarantee by the Company of the lessor’s debt or a loan from the Company to the lessor related to the leased property. Future minimum lease payments under non-cancellable operating leases as of December 31, 2019 were as follows (in thousands): 2020 $ 11,883 2021 8,779 2022 6,481 2023 5,038 2024 4,803 Thereafter 31,877 Total minimum lease payments 68,861 Less: present value impact 20,704 Present value of operating lease obligations 48,157 Less: current portion 8,436 Long-term portion $ 39,721

Derivative Financial Instrument

Derivative Financial Instruments	12 Months Ended
	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	13. Derivative financial instruments at fair value consisted of the following (in thousands): December 31, 2019 Fair Value Balance Sheet Location Derivatives designated as hedging instruments: Interest rate swaps $ 28,070 Other non-current liabilities Derivatives not designated as hedging instruments: Interest rate swaps $ 3,245 Other non-current assets December 31, 2018 Fair Value Balance Sheet Location Derivatives designated as hedging instruments: Interest rate swaps $ 9,884 Other non-current liabilities Derivatives not designated as hedging instruments: Interest rate swaps $ 1,262 Other non-current liabilities Interest rate swaps $ 130 Other non-current assets The Company is exposed to interest rate risk related to its outstanding debt facilities that have variable interest rates. The Company was previously required to maintain interest rate swaps on a portion of the loan balance of the 2016 Term Loan Facility. During the year ended December 31, 2018, the Company paid off and terminated the 2016 Term Loan Facility and settled all outstanding interest rate swaps associated with the 2016 Term Loan Facility. As a result of settling the interest rate swaps, which were designated as hedges, the Company realized a $22.5 million gain that was recorded as a reduction to interest expense. The Company was previously required to maintain interest rate swaps on a portion of the outstanding loan balance of the Aggregation Facility. The Aggregation Facility and its related interest rate swaps were terminated in August 2019. The settled interest rate swaps were not designated as hedge instruments and changes in the fair value were recorded in other expense (income), net. In connection with the Warehouse Facility, the Company is required to maintain interest rate swaps such that not less than 90% of the aggregate expected amortization profile of all outstanding revolving advances is subject to a fixed interest rate. The Company is required to meet this threshold within five business days after the end of each quarterly period. As of December 31, 2019, the Company had entered into interest rate swaps with an aggregate notional amount of approximately $153.0 million. The Company entered into additional interest rate swaps within five business days of quarter end with an aggregate notional amount of approximately $72.0 million. The Company did not designate these interest rate swaps as hedge instruments and accounts for any changes in fair value in other expense (income), net. In connection with the 2018-2 Notes, the Company entered into interest rate swaps to offset changes in the variable interest rate for a portion of these notes. As of December 31, 2019, the notional amount of these interest rate swaps was $323.6 million. The notional amount of the interest rate swaps decreases through the maturity of the 2018-2 Notes, similar to the Company’s estimated semi-annual principal payments on the 2018-2 Notes through August 2023. The interest rate swaps are designated as cash flow hedges, and unrealized gains or losses are recorded in OCI. The amount of AOCI expected to be reclassified to interest expense within the next 12 months is approximately $4.6 million. The Company will discontinue the hedge accounting designation of these derivatives if interest payments on LIBOR-indexed floating rate loans compared to the payments under the derivatives are no longer highly effective. The Company records derivatives at fair value. The losses on derivatives designated as cash flow hedges recognized in OCI, before tax effect, consisted of the following (in thousands): Year Ended December 31, 2019 2018 Derivatives designated as cash flow hedges: Interest rate swaps $ 19,653 $ 2,311 The losses (gains) on derivative financial instruments recognized in the consolidated statements of operations, before tax effect, consisted of the following (in thousands): Year Ended December 31, 2019 2018 Interest expense, net Other expense (income), net Interest expense, net Other expense (income), net Total amounts presented in the income statement line items $ 82,323 $ 1,434 $ 65,308 $ (4,538 ) Derivatives designated as cash flow hedges: Interest rate swaps Losses (gains) reclassified from AOCI into income $ 1,467 $ — $ (21,601 ) $ — Derivatives not designated as hedging instruments: Interest rate swaps Losses (gains) recognized in income — 1,433 — (2,420 ) Total losses (gains) $ 1,467 $ 1,433 $ (21,601 ) $ (2,420 )

Investment Funds

Investment Funds	12 Months Ended
	Dec. 31, 2019
Summarized Financial Data Of Subsidiary [Abstract]
Investment Funds	14. The Company has formed investment funds for the purpose of funding the purchase of solar energy systems under long-term customer contracts. As of December 31, 2019, and 2018, the aggregate carrying value of these funds’ assets and liabilities (after elimination of intercompany transactions and balances) in the Company’s consolidated balance sheets were as follows (in thousands): December 31, December 31, 2019 2018 Assets Current assets: Cash and cash equivalents $ 82,764 $ 62,350 Accounts receivable, net 8,922 6,593 Prepaid expenses and other current assets 1,676 1,289 Total current assets 93,362 70,232 Restricted cash and cash equivalents 8,890 2,443 Solar energy systems, net 1,587,354 1,752,271 Other non-current assets, net 504,668 10,888 Total assets $ 2,194,274 $ 1,835,834 Liabilities Current liabilities: Distributions payable to non-controlling interests and redeemable non-controlling interests $ 10,253 $ 7,846 Current portion of long-term debt 3,622 1,512 Current portion of deferred revenue 2,590 2,320 Accrued and other current liabilities 6,394 4,860 Total current liabilities 22,859 16,538 Long-term debt, net of current portion 197,952 53,505 Deferred revenue, net of current portion 12,242 9,694 Other non-current liabilities 301 1,023 Total liabilities $ 233,354 $ 80,760 The Company consolidates the investment funds in which it has an equity interest, and all intercompany balances and transactions between the Company and the investment funds are eliminated in the consolidated financial statements. The Company determined that each of these investment funds meets the definition of a VIE. The Company uses a qualitative approach in assessing the consolidation requirement for VIEs that focuses on determining whether the Company has the power to direct the activities of the VIE that most significantly affect the VIE’s economic performance and whether the Company has the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. The Company has considered the provisions within the contractual arrangements that grant it power to manage and make decisions that affect the operation of these VIEs, including determining the solar energy systems and associated long-term customer contracts to be sold or contributed to the VIE, and installation, operation and maintenance of the solar energy systems. The Company considers that the rights granted to the other investors under the contractual arrangements are more protective in nature rather than participating rights. As such, the Company has determined it is the primary beneficiary of the VIEs for all periods presented. The Company evaluates its relationships with the VIEs on an ongoing basis to ensure that it continues to be the primary beneficiary. Under the fund agreements, cash distributions of income and other receipts by the funds, net of agreed-upon expenses and estimated expenses, tax benefits and detriments of income and loss, and tax benefits of tax credits, are assigned to the fund investors and the Company’s subsidiaries as specified in contractual arrangements. As such, the cash held in investment funds is not readily available to the Company due to the timing of distributions. Certain of these fund arrangements have call and put options to acquire the investor’s equity interest as specified in the contractual agreements. Once the investor’s equity interest is acquired by the Company, the assets, liabilities and operations of the investment fund become wholly owned and no longer require an assessment of non-controlling interests . Fund investors for three of the funds are managed indirectly by The Blackstone Group L.P. (the “Sponsor”) and are considered related parties. As of December 31, 2019 and 2018, the cumulative total of contributions into the VIEs by all investors was $1,949.7 million and $1,565.3 million. Of these contributions, a cumulative total of $110.0 million was contributed by related parties in prior periods. A third-party provider has agreed to perform backup maintenance services for all funds, if necessary. Lease Pass-Through Financing Obligation During 2015, a wholly owned subsidiary of the Company entered into a lease pass-through fund arrangement under which the Company contributed solar energy systems and the investor contributed cash. The net carrying value of the related solar energy systems was $43.8 million and $55.8 million as of December 31, 2019 and 2018. The Company accounts for the residual of the large upfront payments, net of amounts allocated to the ITCs, and subsequent periodic payments received from the fund investor as a borrowing by recording the proceeds received as a lease pass-through financing obligation, which will be repaid through customer payments that will be received by the investor. Under this approach, the Company continues to account for the arrangement with the customers in its consolidated financial statements, whether the cash generated from the customer arrangements is received by the Company’s wholly owned subsidiary or paid directly to the fund investor. A portion of the amounts received by the fund investor from customer payments is applied to reduce the lease pass-through financing obligation, and the balance is allocated to interest expense. The customer payments are recognized into revenue based on cash receipts during the period as required by GAAP. Interest is calculated on the lease pass-through financing obligation using the effective interest rate method. The effective interest rate is the interest rate that equates the present value of the cash amounts to be received by a fund investor over the master lease term with the present value of the cash amounts paid by the investor to the Company, adjusted for any payments made by the Company. Any additional master lease prepayments by the investor would be recorded as an additional lease pass-through financing obligation, while any refunds of master lease prepayments would reduce the lease pass-through financing obligation. The lease pass-through financing obligation is nonrecourse. As of December 31, 2019 and 2018, the Company had recorded financing liabilities of $4.6 million and $5.3 million related to this fund arrangement, which was the lease pass-through financing obligation recorded in other liabilities. Guarantees With respect to the investment funds, the Company and the fund investors have entered into guaranty agreements under which the Company guarantees the performance of certain financial obligations of its subsidiaries to the investment funds. These guarantees do not result in the Company being required to make payments to the fund investors unless such payments are mandated by the investment fund governing documents and the investment fund fails to make such payment. Each of the Company’s investment funds and financing subsidiaries maintains separate books and records from each other and from the Company. The assets of each investment fund are not available to satisfy the debts or obligations of any other investment fund, subsidiary or the Company. The Company is contractually obligated to make certain VIE investors whole for losses that the investors may suffer in certain limited circumstances resulting from the disallowance or recapture of ITCs. The Company has concluded that the likelihood of a significant recapture event is remote and consequently has not recorded any liability in the consolidated financial statements for any potential recapture exposure. The maximum potential future payments that the Company could have to make under this obligation would depend on the IRS successfully asserting upon audit that the fair market values of the solar energy systems sold or transferred to the funds as determined by the Company exceeded the allowable basis for the systems for purposes of claiming ITCs. The fair market values of the solar energy systems and related ITCs are determined and the ITCs are allocated to the fund investors in accordance with the funds’ governing agreements. Due to uncertainties associated with estimating the timing and amounts of distributions, the likelihood of an event that may trigger repayment, forfeiture or recapture of ITCs to such investors, and the fact that the Company cannot determine how the IRS will evaluate system values used in claiming ITCs, the Company cannot determine the potential maximum future payments that are required under these guarantees. As of December 31, 2019, the Company has not made any payments under these guarantees. However, several recent investment funds, the 2018-1 Notes and the 2018-2 Notes have required the Company to prepay insurance premiums to cover the risk of ITC recapture. The Company amortizes this prepaid insurance expense over the ITC recapture period. The Company had prepaid insurance balances of $8.1 million and $8.3 million as of December 31, 2019 and 2018. From time to time, the Company incurs fees for non-performance, which non-performance may include, but is not limited to, delays in the installation process and interconnection to the power grid of solar energy systems and other factors. Based on the terms of the investment fund agreements, the Company will either reimburse a portion of the fund investor’s capital or pay the fund investor a non-performance fee. Distributions paid to reimburse fund investors totaled $2.6 million and $11.9 million for the years ended December 31, 2019 and 2018. As of December 31, 2019, the company accrued an estimated 1.1 As a result of the guaranty arrangements in certain funds, the Company was required to hold a minimum cash balance of $10.0 million as of December 31, 2019 and 2018, which is classified as restricted cash and cash equivalents.

Redeemable Non-Controlling Inte

Redeemable Non-Controlling Interests and Equity and Preferred Stock	12 Months Ended
	Dec. 31, 2019
Equity [Abstract]
Redeemable Non-Controlling Interests and Equity and Preferred Stock	15 . Redeemable Non-Controlling Interests and Equity and Preferred Stock Common Stock The Company has 1.0 billion authorized shares of common stock. As of December 31, 2019 and 2018, the Company had 123.1 million and 120.1 million shares of common stock issued and outstanding. The Company had shares of common stock reserved for issuance as follows (in thousands): December 31, December 31, 2019 2018 Shares available for grant under equity incentive plans 13,060 13,323 Restricted stock units issued and outstanding 6,271 6,172 Stock options issued and outstanding 5,421 3,394 Long-term incentive plan 2,706 2,706 Total 27,458 25,595 Redeemable Non-Controlling Interests and Non-Controlling Interests Seven of the investment funds include a right for the non-controlling interest holder to require the Company’s wholly owned subsidiary to purchase all of its membership interests in the fund (each, a “Put Option”). The purchase price for the fund investor’s interest in the seven investment funds under the Put Options is the greater of fair market value at the time the option is exercised and a specified amount, ranging from $2.1 million to $4.1 million. The Put Options for these seven investment funds are exercisable beginning on the date that specified conditions are met for each respective fund. The first of the Put Options are expected to become exercisable beginning in the second quarter of 2021. Because the Put Options represent redemption features that are not solely within the control of the Company, the non-controlling interests in these investment funds are presented outside of permanent equity. Redeemable non-controlling interests are recorded using the greater of their carrying value at each reporting date (which is impacted by attribution under the HLBV method) or their estimated redemption value in each reporting period. In all investment funds except one, the Company’s wholly owned subsidiary has the right to require the non-controlling interest holder to sell all of its membership units to the Company’s wholly owned subsidiary (each, a “Call Option”). The purchase price for the fund investors’ interests under the Call Options varies by fund, but is generally the greater of a specified amount, which ranges from approximately $1.2 million to $7.0 million, the fair market value of such interest at the time the option is exercised, or an amount that causes the fund investor to achieve a specified return on investment. The Call Options are exercisable beginning on the date that specified conditions are met for each respective fund. The first of the Call Options are expected to become exercisable beginning in the third quarter of 2020. Preferred Stock The company has 10.0 million shares of preferred stock authorized that is issuable in series. As of December 31, 2019 and 2018, there were no series of preferred stock issued or designated.

Equity Compensation Plans

Equity Compensation Plans	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Compensation Plans	16. Equity Incentive Plans 2014 Equity Incentive Plan The Company currently grants equity awards through its 2014 Equity Incentive Plan (the “2014 Plan”). Under the 2014 Plan, the Company may grant stock options, restricted stock, restricted stock units (“RSUs”), stock appreciation rights, performance stock units, performance shares and performance awards to its employees, directors and consultants, and its parent and subsidiary corporations’ employees and consultants. As of December 31, 2019, a total of 13.1 million shares of common stock were available for grant under the 2014 plan, subject to adjustment in the case of certain events. In addition, any shares that otherwise would be returned to the Omnibus Plan (as defined below) as the result of the expiration or termination of stock options may be added to the 2014 Plan. The number of shares available to grant under the 2014 Plan is subject to an annual increase on the first day of each year, equal to the least of 8.8 million shares, 4% of the outstanding shares of common stock as of the last day of the immediately preceding fiscal year and an amount of shares as determined by the Company. In accordance with the annual increase, an additional 4.8 million shares became available to grant in January 2019 under the 2014 Plan. 2013 Omnibus Incentive Plan; Non-plan Option Grant T he Company’s 2013 Omnibus Incentive Plan (the “Omnibus Plan”) was terminated in connection with the adoption of the 2014 Plan in September 2014, and accordingly no additional shares are available for issuance under the Omnibus Plan. The Omnibus Plan will continue to govern outstanding awards granted under the plan. The stock options outstanding under the Omnibus Plan have a ten-year contractual period. Long-term Incentive Plan In July 2013, the Company’s board of directors approved 4.1 million shares of common stock for six Long-term Incentive Plan Pools (“LTIP Pools”) that comprise the 2013 Long-term Incentive Plan (the “LTIP”). Participants in the LTIP are allocated a portion of the LTIP Pools relative to the performance of other participants on a measurement date that is determined once performance conditions are met. As of December 31, 2019, 1.1 million shares of common stock had been awarded to participants under the LTIP and 0.3 million shares had been returned to the 2014 Plan. As of December 31, 2019, 2.7 million shares remained outstanding, which will be granted when certain performance conditions are achieved. Vesting Terms As of December 31, 2019, there were 5.4 million time-based stock options and 6.3 million RSUs granted and outstanding under the Company’s equity compensation plans. The time-based options are subject to ratable time-based vesting over three to four years. Of the total RSUs outstanding, 5.1 million are subject to ratable time-based vesting over one to four years and 1.2 million vest quarterly or annually over two to four years subject to individual participants’ achievement of quarterly or annual performance goals. Stock Options Stock Option Activity Stock option activity for the year ended December 31, 2019 was as follows (in thousands, except term and per share amounts): Weighted- Weighted- Average Shares Average Remaining Aggregate Underlying Exercise Contractual Intrinsic Options Price Term (in years) Value Outstanding—December 31, 2018 3,394 $ 2.77 $ 4,689 Granted 2,674 5.60 Exercised (578 ) 1.73 Cancelled (69 ) 7.53 Outstanding—December 31, 2019 5,421 $ 4.21 7.8 $ 17,073 Options vested and exercisable—December 31, 2019 1,989 $ 2.65 5.7 $ 9,551 The weighted-average grant date fair value of options granted during the years ended December 31, 2019 and 2018 was $3.52 and $3.93 per share. The total intrinsic value of options exercised for the years ended December 31, 2019 and 2018 was $3.2 million and $4.4 million. Intrinsic value is calculated as the difference between the exercise price of the underlying options and the fair value of the common stock for the options that had exercise prices that were lower than the fair value per share of the common stock. The total fair value of options vested for the years ended December 31, 2019 and 2018 was $2.0 million and $1.7 million. Determination of Fair Value of Stock Options The Company estimates the fair value of the time-based stock options granted on each grant date using the Black-Scholes-Merton option pricing model and applies the accelerated attribution method for expense recognition. The fair values using the Black-Scholes-Merton method were estimated on each grant date using the following weighted-average assumptions: Year Ended December 31, 2019 2018 Expected term (in years) 6.3 6.2 Volatility 67.8 % 70.7 % Risk-free interest rate 2.3 % 2.8 % Dividend yield 0.0 % 0.0 % Use of the Black-Scholes-Merton option-pricing model requires the input of highly subjective assumptions, including (1) the expected term of the option, (2) the expected volatility of the price of the Company’s common stock, (3) risk-free interest rates and (4) the expected dividend yield of the Company’s common stock. The assumptions used in the option-pricing model represent management’s best estimates. These estimates involve inherent uncertainties and the application of management’s judgment. If factors change and different assumptions are used, the Company’s stock-based compensation expense could be materially different in the future. These assumptions and estimates are as follows: • Expected Term. The expected term represents the period that the Company’s option awards are expected to be outstanding. The Company utilized the simplified method in estimating the expected term of its options granted. The simplified method deems the term to be the average of the time to vesting and the contractual life of the options. • Expected Volatility. The volatility is derived from the average historical stock volatilities of the Company and a peer group of public companies within the Company’s industry that it considers to be comparable to its business over a period equivalent to the expected term of the stock-based grants. The Company did not rely on implied volatilities of traded options in its own or the industry peers’ common stock because of the low volume of activity. • Risk-Free Interest Rate. The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for zero-coupon U.S. Treasury notes with maturities approximately equal to the option’s expected term. • Dividend Yield. The Company has never declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. Consequently, the Company used an expected dividend yield of zero. RSUs RSU activity for the year ended December 31, 2019 was as follows (awards in thousands): Weighted- Average Number of Grant Date Awards Fair Value Outstanding at December 31, 2018 6,172 $ 3.84 Granted 3,130 6.01 Vested (2,364 ) 3.83 Forfeited (667 ) 4.51 Outstanding at December 31, 2019 6,271 $ 4.85 The total fair value of RSUs vested was $16.2 million and $16.9 million, for the years ended December 31, 2019 and 2018. The Company determined the fair value of RSUs granted on each grant date based on the fair value of the Company’s common stock on the grant date. Stock-Based Compensation Expense Stock-based compensation was included in operating expenses as follows (in thousands): Year Ended December 31, 2019 2018 Cost of revenue $ 1,653 $ 1,333 Sales and marketing 3,305 3,353 General and administrative 11,330 8,344 Research and development 130 133 Total stock-based compensation $ 16,418 $ 13,163 The recognized income tax benefit related to share-based compensation was $2.2 million and $1.4 million for the years ended December 31, 2019 and 2018. Unrecognized stock-based compensation expense for time-based stock options and RSUs as of December 31, 2019 was as follows (in thousands, except years): Unrecognized Weighted- Stock-Based Average Period Compensation of Recognition Expense (in years) RSUs $ 18,726 1.7 Stock options 7,073 2.0 Total unrecognized stock-based compensation expense $ 25,799

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	17. Income tax expense is composed of the following (in thousands): Year Ended December 31, 2019 2018 Current: Federal $ (711 ) $ (665 ) State 162 102 Total current benefit (549 ) (563 ) Deferred: Federal 101,965 79,048 State 49,583 27,814 Total deferred expense 151,548 106,862 Income tax expense $ 150,999 $ 106,299 The Company operates in only one federal jurisdiction, the United States. The following table presents a reconciliation of the income tax benefit computed at the statutory federal rate and the Company’s income tax expense (in thousands): Year Ended December 31, 2019 2018 Income tax benefit—computed as 21% of pretax loss $ (57,187 ) $ (36,385 ) Effect of non-controlling interests and redeemable non-controlling interests 67,440 55,434 State and local income tax expenses (net of federal benefit) 39,299 22,054 Tax gains on sale of solar energy systems to investment funds 103,689 68,683 Effect of tax credits (2,781 ) (2,684 ) Other 539 (803 ) Income tax expense $ 150,999 $ 106,299 Deferred income taxes reflect the impact of temporary differences between assets and liabilities for financial reporting purposes and the amounts recognized for income tax reporting purposes, net operating loss carryforwards and other tax credits. The differences are measured by applying currently enacted tax laws. The significant components of the Company’s deferred tax assets and liabilities were as follows (in thousands): December 31, 2019 2018 Deferred tax assets: Accruals and reserves $ 13,719 $ 6,552 Stock-based compensation 5,698 4,204 Investment tax and other credits 51,721 49,194 Net operating losses 16,218 13,662 Interest rate swaps 6,752 2,982 Other 411 1,149 Gross deferred tax assets 94,519 77,743 Valuation allowance (314 ) (306 ) Net deferred tax assets 94,205 77,437 Deferred tax liabilities: Investment in solar funds (648,267 ) (483,522 ) Fixed asset depreciation and amortization (29,633 ) (31,035 ) Gross deferred tax liabilities (677,900 ) (514,557 ) Net deferred tax liabilities $ (583,695 ) $ (437,120 ) The Company sells solar energy systems to the investment funds for income tax purposes. As the investment funds are consolidated by the Company, the gain on the sale of the solar energy systems is eliminated in the consolidated financial statements. However, this gain is recognized for tax reporting purposes. The Company accounts for the income tax consequences of these intra-entity transfers, both current and deferred, as a component of income tax expense and deferred tax liability, net during the period in which the transfers occur. The Company reported federal net operating loss carryforwards (“NOLs”) of approximately $8.1 million and $13.9 million available to offset future federal taxable income as of December 31, 2019 and 2018. The Company’s federal NOLs do not expire. The Company reported state NOLs of approximately $230.9 million and $175.3 million available to offset future state taxable income as of December 31, 2019 and 2018. The NOLs expire in varying amounts from 2029 through 2039 for state tax purposes if unused. As of December 31, 2019 and 2018, the Company recognized a valuation allowance of $0.3 million for the existing state NOLs and other existing state tax attributes due to state-imposed limitations on their utilization. The Company reported federal business tax credit carryforwards, primarily composed of ITCs, of $48.5 million and $45.7 million for the years ended December 31, 2019 and 2018. These federal business tax credits expire in varying amounts from 2036 through 2039 if unused. The Company accounts for its federal business tax credits as a reduction of income tax expense in the year in which the credits arise. The Company reported AMT credits of $0.4 million and $0.5 million for the years ended December 31, 2019 and 2018. As of December 31, 2019 and 2018, the Company had $1.3 million and $0.6 million of federal income tax refunds receivable which were recorded in prepaid expenses and other current assets. As of December 31, 2019 and 2018, the Company had $6.9 million and $9.3 million of state income tax refunds receivable which were recorded in prepaid expenses and other current assets. The Company expects to produce sufficient future taxable income, including from the future reversal of deferred tax liabilities, of the necessary character and in the necessary periods and jurisdictions to support the realization of the deferred tax assets. As such, no valuation allowance is required except for as previously noted. Uncertain Tax Positions As of December 31, 2019, the total amount of gross unrecognized tax benefits was $1.0 million, of which $0.9 million, if recognized, would impact the Company’s effective tax rate. As of December 31, 2018, the total amount of gross unrecognized tax benefits was $0.6 million, of which $0.5 million, if recognized, would impact the Company’s effective tax rate. The aggregate changes in the balance of gross unrecognized tax benefits, which excludes interest and penalties, for the years ended December 31, 2019 and 2018, is as follows (in thousands): Year Ended December 31, 2019 2018 Beginning balance $ 555 $ — Increases related to positions from a prior year 230 447 Increases related to positions from the current year 172 108 Ending balance $ 957 $ 555 The Company’s policy is to include interest and penalties related to unrecognized tax benefits, if any, within the provision for income taxes. There were no interest and penalties accrued for any unrecognized tax benefits as of December 31, 2019 and 2018. The Company does not have any tax positions for which it is reasonably possible the total amount of gross unrecognized tax benefits will significantly increase or decrease within 12 months of the year ended December 31, 2019. The Company is subject to taxation and files income tax returns in the United States and various state and local jurisdictions. The U.S. and state jurisdictions in which the Company operates have statutes of limitations that generally range from three to four years. The Company’s federal, state and local income tax returns starting with the 2016 tax year are subject to audit. The Company’s 2015 income tax returns for six states and 2014 income tax return for one state are also subject to audit

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions	18. The Company’s consolidated statements of operations included related party transactions of $1.8 million and $2.2 million within sales and marketing for the years ended December 31, 2019 and 2018. Vivint Services The Company has a number of agreements with its sister company, Vivint. The Company has a sales dealer agreement with Vivint, pursuant to which each company will act as a non-exclusive dealer for the other party to market, promote and sell each other’s products. The agreement will continue to automatically renew unless written notice of termination is provided by one of the parties to the other. The Company and Vivint have also agreed to non-solicitation provisions under a non-competition agreement that matches the term of the sales dealer agreement. The Company made payments under agreements with Vivint of $7.1 million and $16.3 million for the years ended December 31, 2019, and 2018. These amounts reflect the level of services provided by Vivint on behalf of the Company. Under agreements with Vivint, the Company recorded payable balances to Vivint of $2.2 million and $0.2 million in accounts payable as of December 31, 2019 and 2018. Advances Receivable — Net a Investment Funds Fund investors for three of the investment funds are indirectly managed by the Sponsor and accordingly are considered related parties. The Company accrued equity distributions to these entities of $1.4 million and $1.5 million as of December 31, 2019 and 2018, included in distributions payable to non-controlling and redeemable non-controlling interests. See Note 14—Investment Funds.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	19. Letters of Credit As of December 31, 2019, the Company had established letters of credit under the Asset Financing Facility for up to $19.6 million related to insurance contracts. See Note 11—Debt Obligations. Indemnification Obligations From time to time, the Company enters into contracts that contingently require it to indemnify parties against claims. These contracts primarily relate to provisions in the Company’s services agreements with related parties that may require the Company to indemnify the related parties against services rendered; and certain agreements with the Company’s officers and directors under which the Company may be required to indemnify such persons for liabilities. In addition, under the terms of the agreements related to the Company’s investment funds and other material contracts, the Company may also be required to indemnify fund investors and other third parties for liabilities. For further information see Note 14—Investment Funds. Residual Commission Payments The Company pays a portion of sales commissions to its sales professionals on a deferred basis. The amount deferred is based on the value of the system sold by the sales professional and payment is based on the sales professional remaining employed by the Company. As this amount is earned over time, it is not considered an incremental cost of obtaining the contract due to the requirement that the sales professional remain in the Company’s service. As a result, the amount that is earned over time is expensed by the Company over the deferment period. As of December 31, 2019, the total estimated obligation that is currently not recorded in the Company’s consolidated financial statements, but that will be earned and expensed over the deferment period was $5.2 million. As part of the settlement of the February 2018 class action (see “—Legal Proceedings” below), it was agreed that for certain sales professionals who were part of the Company’s residual commission plan who terminate after August 31, 2019, the Company will be required to pay 50% of unpaid deferred residual commissions in equal installments over the 18 months following such termination. Previously, amounts unpaid under the residual commissions plan would be forfeited when these certain sales professionals terminated their employment. As such, the Company’s accrual for the residual commission plan was increased in the third quarter of 2019 by $5.9 million, which was recorded in sales and marketing expense, to accrue for the portion of the residual payments that were considered earned as a result of the settlement. Legal Proceedings and Regulatory Matters In February 2018, two former employees, on behalf of themselves and other direct sellers, named the Company in a putative class and Private Attorneys General Act action in San Diego County Superior Court, California, alleging that the Company misclassified those employees and violated other wage and hour laws. The complaint seeks unspecified damages and statutory penalties for the alleged violations. The Company disputes the allegations and has retained counsel to defend it in the litigation. On October 7, 2019, the Company entered into a class action settlement agreement, pursuant to which the Company has agreed to pay up to $7.25 million to settle the claims in the lawsuit, which was accrued by the Company in general and administrative expense in the third quarter of 2019. The settlement is subject to court approval. On December 6, 2019, the court granted preliminary approval of the settlement. The final settlement approval hearing is scheduled for May 22, 2020. In March 2018, the New Mexico Attorney General’s office filed an action against the Company and several of its officers in New Mexico State Court, alleging violation of state consumer protection statutes and other claims. The Company disputes the allegations in the lawsuit and intends to defend itself in the action. The Company is unable to estimate a range of loss, if any, were there to be an adverse final decision. If an unfavorable outcome were to occur in this case, it is possible that the impact could be material to the Company’s results of operations in the period(s) in which any such outcome becomes probable and estimable. In July 2018, an individual filed a putative class action lawsuit in the U.S. District Court for the District of Columbia, purportedly on behalf of himself and other persons who received certain telephone calls. The lawsuit alleges that the Company violated the Telephone Consumer Protection Act and some of its implementing regulations. The complaint seeks statutory penalties for each alleged violation. The Company disputes the allegations in the complaint, has retained counsel and intends to vigorously defend itself in the litigation. In August 2019, the Company reached a settlement in principle to resolve the class action on a nationwide basis for a payment of approximately $1.0 million (including plaintiff’s attorneys’ fees), which was accrued by the Company in general and administrative expense in the third quarter of 2019. On November 8, 2019, the court granted preliminary approval of the settlement. The final settlement approval hearing is scheduled for April 10, 2020. In October 2018, a former employee filed a representative action in Sacramento County Superior Court, California, pursuant to California’s Private Attorneys General Act alleging that the Company violated California labor and employment laws by, among other things, failing to provide its employees with rest and meal breaks. The Company disputes the allegations in the complaint and has retained counsel to represent it in the litigation. The Company is unable to estimate a range of loss, if any, at this time. If an unfavorable outcome were to occur in the case, it is possible that the impact could be material to the Company’s results of operations in the period(s) in which any such outcome becomes probable and estimable. In October 2018, a former sales professional filed a representative action in Orange County Superior Court, California, pursuant to California’s Private Attorneys General Act alleging that the Company violated California labor and employment laws by, among other things, failing to properly compensate its direct sellers and reimburse them for business expenses. The Company disputes the allegations in the complaint. In November 2019, the parties entered into an agreement pursuant to which the plaintiff agreed that the resolution of the February 2018 class action referenced above would resolve all of the claims in this action. In June 2019, a former sales professional filed a representative action in San Diego County Superior Court, California, pursuant to California’s Private Attorneys General Act alleging that the Company violated California labor and employment laws by, among other things, failing to properly compensate its direct sellers and reimburse them for business expenses. The Company disputes the allegations in the complaint. The resolution of the February 2018 class action referenced above is expected to resolve the representative claims pursuant to California’s Private Attorneys General Act. In October 2019, two separate, purported stockholders filed separate putative class actions in the U.S. District Court for the Eastern District of New York purportedly on behalf of themselves and all others similarly situated. The lawsuits allege violations of federal securities laws and seek unspecified compensatory damages, attorneys’ fees and costs. The Company has not yet responded to either complaint and reserves all of its rights and objections with regard to service of process, jurisdictional challenges, and venue as well as any other objections and motions related to the complaints. The Company disputes the allegations in the complaints and has retained counsel to represent it in the litigation. The Company is unable to estimate a range of loss, if any, at this time. If an unfavorable outcome were to occur in either case, it is possible that the impact could be material to the Company’s results of operations in the period(s) in which any such outcome becomes probable and estimable. In December 2019, ten customers who signed residential power purchase agreements named the Company in a putative class action lawsuit in the U.S. District Court for the Northern District of California alleging that the agreements contain unlawful termination fee provisions. The Company disputes the allegations in the complaint and has retained counsel to represent it in the litigation. The Company is unable to estimate a range of loss, if any, at this time. If an unfavorable outcome were to occur in this case, it is possible that the impact could be material to the Company’s results of operations in the period(s) in which any such outcome becomes probable and estimable. In December 2019, two former installers filed a putative class action wage and hour lawsuit against the Company in the U.S. District Court for the Central District of California. In February 2020, the two installers filed a First Amended Complaint, which added a Private Attorneys General Act (“PAGA”) claim. In March 2020, Plaintiffs advised that they would dismiss their class claims with prejudice and their individual claims without prejudice and would pursue only their PAGA claim. The Company disputes the allegations in the complaint and has retained counsel to represent it in the litigation. The Company is unable to estimate a range of loss, if any, at this time. If an unfavorable outcome were to occur in this case, it is possible that the impact could be material to the Company’s results of operations in the period(s) in which any such outcome becomes probable and estimable. In December 2019, a former installer filed a representative action in San Diego Superior Court, California, asserting various wage and hour claims. The Company disputes the allegations in the complaint and has retained counsel to represent it in the litigation. The Company is unable to estimate a range of loss, if any, at this time. If an unfavorable outcome were to occur in this case, it is possible that the impact could be material to the Company’s results of operations in the period(s) in which any such outcome becomes probable and estimable. In January 2020, the Company entered into a settlement agreement called an Assurance of Discontinuance (“Settlement”) with the New York Attorney General (“NYAG”). The Settlement requires that the Company adopt certain changes to its sales and marketing practices in New York and pay approximately $2.0 million to the State of New York. The Company accrued this amount in its financial statements as of December 31, 2019, and already paid $1.0 million in January 2020. The Settlement requires that the Company notify New York customers about the Settlement and their potential rights under it, including the potential rights to have the Company remove their system, leave their property in a watertight condition, cancel contracts, and refund amounts paid, and/or to repair property damage. The NYAG will be the final arbiter of any disputes as to the consumer’s eligibility for relief. The Company has accrued another $2.0 million for this potential liability in general and administrative expenses for the period ending December 31, 2019, which represents the Company’s current best estimate of potential loss. Future adjustments to the Company’s current accrual, which currently cannot be estimated, could adversely impact the Company’s operating results in the period or periods in which any such adjustments are made. Actual expenses may deviate materially from the Company’s estimate. In addition to the matters discussed above, in the normal course of business, the Company has from time to time been named as a party to various legal claims, actions and complaints. While the outcome of these matters cannot currently be predicted with certainty, the Company does not currently believe that the outcome of any of these claims will have a material adverse effect, individually or in the aggregate, on its consolidated financial position, results of operations or cash flows. The Company accrues for losses that are probable and can be reasonably estimated. The Company evaluates the adequacy of its legal reserves based on its assessment of many factors, including interpretations of the law and assumptions about the future outcome of each case based on available information.

Basic and Diluted Net Loss Per

Basic and Diluted Net Loss Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Share	20. The Company computes basic net earnings per share by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding for the period. Diluted earnings per share reflects the potential dilution of securities that could be exercised or converted into common shares and is computed by dividing net earnings available to common stockholders by the weighted-average number of common shares outstanding plus the effect of potentially dilutive shares to purchase common stock. The following table sets forth the computation of the Company’s basic and diluted net loss attributable per share to common stockholders for the years ended December 31, 2019 and 2018 (in thousands, except per share amounts): Year Ended December 31, 2019 2018 Numerator: Net loss attributable to common stockholders $ (102,175 ) $ (15,592 ) Denominator: Shares used in computing net loss attributable per share to common stockholders, basic and diluted 121,310 117,565 Net loss attributable per share to common stockholders: Basic and diluted $ (0.84 ) $ (0.13 ) For all periods presented, the Company incurred net losses attributable to common stockholders. As such, the effect of the Company’s outstanding stock options and restricted stock units were not included in the calculations of diluted net loss attributable per share to common stockholders as the effect would have been anti-dilutive. The following table contains share totals with a potentially dilutive impact (in thousands): Year Ended December 31, 2019 2018 Restricted stock units 6,271 6,172 Stock options 5,421 3,394 Total 11,692 9,566

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	21. Investment Funds In February 2020, a wholly owned subsidiary of the Company entered into an investment fund arrangement with an existing fund investor. The total commitment under the investment fund arrangement is $50.0 million. The Company’s wholly owned subsidiary has the right to elect to require the fund investor to sell all of its membership units to the Company’s wholly owned subsidiary once certain conditions have been met. If the Company does not elect to purchase all of the fund investor’s membership units once certain conditions are met, the fund investor has the option to require the Company to purchase all of its membership units. The purchase price for the fund investor’s interests is determined based on the fair market value of those interests at the time the option is exercised. The Company has not yet completed its assessment of whether the investment fund arrangement is a VIE.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The accompanying consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) and reflect the accounts and operations of the Company, its subsidiaries in which the Company has a controlling financial interest and the investment funds formed to fund the purchase of solar energy systems under long-term customer contracts, which are consolidated as variable interest entities (“VIEs”). The Company uses a qualitative approach in assessing the consolidation requirement for VIEs. This approach focuses on determining whether the Company has the power to direct the activities of the VIE that most significantly affect the VIE’s economic performance and whether the Company has the obligation to absorb losses or the right to receive benefits that could potentially be significant to the VIE. All of these determinations involve significant management judgments. The Company has determined that it is the primary beneficiary in the operational VIEs in which it has an equity interest. The Company evaluates its relationships with the VIEs on an ongoing basis to ensure that it continues to be the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. For additional information regarding these VIEs, see Note 14—Investment Funds. Beginning with the first quarter of 2019, the consolidated statements of operations items formerly captioned “Operating leases and incentives” and “Cost of revenue—operating leases and incentives” are now captioned “Customer agreements and incentives” and “Cost of revenue—customer agreements and incentives.” Also beginning with the first quarter of 2019, the consolidated balance sheet items formerly captioned “Current portion of capital lease obligation” and “Capital lease obligation, net of current portion” are now captioned “Current portion of finance lease obligation” and “Finance lease obligation, net of current portion.” Amounts in these balance sheet items were capital leases under Accounting Standards Codification 840: Leases (“Topic 840”) in periods ending prior to January 1, 2019, while amounts in these balance sheet items are finance leases under Accounting Standards Codification 842: Leases (“Topic 842”) in periods ending subsequent to January 1, 2019. See “—Leases” below for further explanation of these changes.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. The Company regularly makes significant estimates and assumptions including, but not limited to, ITCs; revenue recognition; solar energy systems, net; the impairment analysis of long-lived assets; stock-based compensation; the provision for income taxes; the valuation of derivative financial instruments; the recognition and measurement of loss contingencies; and non-controlling interests and redeemable non-controlling interests. The Company bases its estimates on historical experience and on various other assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ materially from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with maturities of three months or less at the time of purchase to be cash and cash equivalents. Cash equivalents consist principally of time deposits and money market accounts with high quality financial institutions.
Restricted Cash	Restricted Cash The Company’s guaranty agreements with certain of its fund investors require the maintenance of minimum cash balances of $10.0 million. For additional information, see Note 14—Investment Funds. As of December 31, 2019, the Company also had $79.9 million in required reserves outstanding in separate collateral accounts in accordance with the terms of its various debt obligations. For additional information, see Note 11—Debt Obligations. These minimum cash balances are classified as restricted cash.
Liquidity	Liquidity In order to grow, the Company requires cash to finance the deployment of solar energy systems. As of the date of this filing, the Company will require additional sources of cash beyond current cash balances, and currently available financing facilities to fund long-term planned growth. If the Company is unable to secure additional financing when needed, or upon desirable terms, the Company may be unable to finance installation of customers’ systems in a manner consistent with past performance, cost of capital could increase, or the Company may be required to significantly reduce the scope of operations, any of which would have a material adverse effect on the business, financial condition, results of operations and prospects. While the Company believes additional financing is available and will continue to be available to support current levels of operations, the Company believes it has the ability and intent to reduce operations to the level of available financial resources for at least the next 12 months from the date of this report, if necessary.
Accounts Receivable, Net	Accounts Receivable, Net Accounts receivable are recorded at the invoiced amount, net of allowance for doubtful accounts. Accounts receivable also include unbilled accounts receivable, which is composed of the monthly PPA power generation not yet invoiced and the monthly bill rate of Solar Leases as of the end of the reporting period. The Company estimates its allowance for doubtful accounts based upon the collectability of the receivables in light of historical trends and adverse situations that may affect customers’ ability to pay. Revisions to the allowance are recorded as an adjustment to bad debt expense or as a reduction to revenue when collectability is not reasonably assured. After appropriate collection efforts are exhausted, specific accounts receivable deemed to be uncollectible would be charged against the allowance in the period they are deemed uncollectible. Recoveries of accounts receivable previously written-off are recorded as credits to bad debt expense. The Company had an allowance for doubtful accounts of $9.4 million and $5.2 million as of December 31, 2019 and 2018.
Inventories	Inventories Inventories include solar energy systems under construction that have yet to be interconnected to the power grid and that will be sold to customers. Inventory is stated at the lower of cost, on a first-in, first-out (“FIFO”) basis, or net realizable value. Upon interconnection to the power grid, solar energy system inventory is removed using the specific identification method. Inventories also include components related to photovoltaic installation products and are stated at the lower of cost, on an average cost basis, or net realizable value. The Company evaluates its inventory reserves on a quarterly basis and writes down the value of inventories for estimated excess and obsolete inventories based on assumptions about future demand and market conditions. See Note 4—Inventories.
Concentrations of Risk	Concentrations of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. The associated concentration risk for cash and cash equivalents is mitigated by banking with creditworthy institutions. At certain times, amounts on deposit exceed Federal Deposit Insurance Corporation insurance limits. Approximately $11.6 million, or 48% of accounts receivable, net as of December 31, 2019 was due from three third-party loan providers that offer financing to System Sales customers. The Company does not require collateral or other security to support accounts receivable. The Company is not dependent on any single customer outside of the third-party loan providers. The Company purchases solar panels, inverters and other system components from a limited number of suppliers. Two suppliers accounted for approximately 91% of the Company’s solar photovoltaic module purchases for the year ended December 31, 2019. Two suppliers accounted for substantially all of the Company’s inverter purchases for the year ended December 31, 2019. If these suppliers fail to satisfy the Company’s requirements on a timely basis or if the Company fails to develop, maintain and expand its relationship with these suppliers, the Company could suffer delays in being able to deliver or install its solar energy systems, experience a possible loss of revenue, or incur higher costs, any of which could adversely affect its operating results. Additionally, certain of the subcomponents of the Company’s equipment are sourced from Asia, including China and other countries in Southeast Asia that have been, or may be, significantly impacted by the coronavirus outbreak. To date, the Company has not seen widespread impacts to its supply but is closely monitoring the situation. Supply chain disruptions could reduce the availability of key components, increase prices or both. If the Company fails to identify or to qualify alternative products on commercially reasonable terms the Company’s operating results and growth prospects would be adversely affected. In addition, the macroeconomic effects of the coronavirus outbreak in China and other markets could result in a widespread health crisis that could adversely affect the economies and financial markets of many countries, resulting in an economic downturn that could affect demand for the Company’s products and likely impact its operating results. Megawatts installed in California accounted for approximately 46% and 38% of total megawatts installed for the years ended December 31, 2019 and 2018. Megawatts installed in the Northeastern United States accounted for approximately 26% and 32% of total megawatts installed for the years ended December 31, 2019 and 2018. Future operations could be affected by changes in the economic conditions in these and other geographic areas, by changes in materials costs, by changes in the demand for renewable energy generated by solar energy systems or by changes or eliminations of solar energy related government incentives.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Assets and liabilities recorded at fair value on a recurring basis in the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: • Level I—Inputs are unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; • Level II—Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities; and • Level III—Unobservable inputs that are significant to the measurement of the fair value of the assets or liabilities that are supported by little or no market data. The Company’s financial instruments measured on a recurring basis consist of Level II assets. See Note 3—Fair Value Measurements.
Investment Tax Credits (ITCs)	Investment Tax Credits (ITCs) The Company receives ITCs under Section 48(a) of the Internal Revenue Code. The amount of the ITC is equal to 30% of the basis of eligible solar property as long as construction of the solar energy system began by December 31, 2019. The Company receives minimal allocations of ITCs for solar energy systems placed in its investment funds as the majority of such credits are allocated to the fund investors. Some of the Company’s investment funds obligate it to make certain fund investors whole for losses that the investors may suffer in certain limited circumstances resulting from the disallowance or recapture of ITCs as a result of the Internal Revenue Service’s (the “IRS”) assessment of the fair value of such systems. The Company has concluded that the likelihood of a recapture event related to these assessments is remote and consequently has not recorded any liability in the consolidated financial statements for any potential recapture exposure. However, several recent investment funds and debt obligations have required the Company to prepay insurance premiums to cover the risk of ITC recapture. The Company amortizes this prepaid insurance expense over the ITC recapture period. The Company receives all ITCs for solar energy systems that are not sold to customers or placed in its investment funds. The Company accounts for its ITCs as a reduction of income tax expense in the year in which the credits arise.
Leases	Leases The Company adopted Topic 842 and its subsequent updates effective January 1, 2019. These updates are intended to increase transparency and comparability among organizations by recognizing right-of-use assets and lease liabilities on the consolidated balance sheets and disclosing key information about leasing arrangements. The Company utilized the additional transition method permitted by Accounting Standards Update (“ASU”) 2018-11 and adopted Topic 842 using a modified retrospective method with a cumulative-effect adjustment to its accumulated deficit as of January 1, 2019. As such, comparative periods ending prior to January 1, 2019 are presented in accordance with Topic 840 and periods ending after January 1, 2019 are presented in accordance with Topic 842. The impact to the accumulated deficit as a result of adopting ASU 2016-02 was a net reduction of approximately $0.2 million. The Company did not use the transitionary practical expedients allowed under Topic 842, and as such, the Company reassessed all contracts existing at the adoption date of January 1, 2019. The Company elected to treat leases with lease terms of 12 months or less as short-term leases. No right-of-use assets or lease liabilities are recognized for short-term leases. The Company has also elected not to separate lease components from non-lease components for all classes of leased assets except for building leases. The adoption of this ASU resulted in right-of-use assets of $34.6 million related to operating leases being recognized in other non-current assets, net on the consolidated balance sheets as of January 1, 2019. Corresponding lease liabilities of $43.8 million related to operating leases were recognized on the consolidated balance sheets as of January 1, 2019, with the current portion recognized in accrued and other current liabilities and the long-term portion recognized in other non-current liabilities. In addition, at January 1, 2019, approximately $1.0 million of lease-related liabilities were removed from accrued and other current liabilities and approximately $8.2 million of lease-related liabilities were removed from other non-current liabilities and included as reductions to the initial operating lease right-of-use assets. As of January 1, 2019, finance lease right-of-use assets of $0.9 million continued to be recorded in property and equipment, net. Any changes in lease terms or estimates subsequent to adoption of the ASU 2016-02 are reflected in the right-of-use assets and lease liabilities. The Company’s PPAs, Solar Leases, and associated rebates and incentives no longer meet the definition of a lease under Topic 842. Accordingly, they are accounted for in accordance with Accounting Standards Codification 606: Revenue from Contracts with Customers (“Topic 606”) beginning on January 1, 2019. The Company concluded that there was no change to its revenue recognition practices for its PPA revenue stream under Topic 606. For Solar Leases, the Company concluded that the impact of applying Topic 606 is immaterial. The Company also concluded that there was no material change related to the timing of revenue recognition for rebates and incentives under Topic 606. Upon the adoption of Topic 842, the Company no longer capitalizes initial direct costs and amortizes them to the respective cost of revenue line items. Instead, the Company now capitalizes costs of obtaining a contract which meet the “incremental” criteria defined in Accounting Standards Codification 340 to other non-current assets, net. These costs are now amortized over the period of benefit to sales and marketing expense on the consolidated statements of operations. In accordance with the Company’s Topic 842 transition discussed above, no prior period amounts were changed. For purposes of comparison, the following tables show how the balances as of December 31, 2018 and for the year ended December 31, 2018 would have changed if the effects of adopting Topic 842 had been applied to those balances (in thousands): December 31, 2018 December 31, 2019 As Reported Adjustments As Adjusted As Reported Solar energy systems, net $ 1,938,874 $ (388,087 ) $ 1,550,787 $ 1,759,861 Other non-current assets, net 28,090 388,087 416,177 680,062 Year Ended December 31, 2018 2019 As Reported Adjustments As Adjusted As Reported Cost of revenue—customer agreements and incentives $ 164,920 $ (18,164 ) $ 146,756 $ 186,325 Cost of revenue—solar energy system and product sales 83,375 (19,060 ) 64,315 72,221 Total cost of revenue 248,295 (37,224 ) 211,071 258,546 Gross profit 42,026 37,224 79,250 82,495 Sales and marketing 58,950 37,224 96,174 151,194 Total operating expenses 154,520 37,224 191,744 271,059
Solar Energy Systems, Net	Solar Energy Systems, Net The Company sells energy to customers through PPAs or leases solar energy systems to customers through Solar Leases. The solar energy systems installed at customers’ homes are stated at cost, less accumulated depreciation and amortization. The Company also sells solar energy systems to customers through System Sales. Systems that are sold to customers are not part of solar energy systems, net. Solar energy systems, net is composed of system equipment costs related to solar energy systems subject to PPAs or Solar Leases. Prior to the implementation of Topic 842 on January 1, 2019, solar energy systems, net also included capitalized initial direct costs. Subsequent to the adoption of Topic 842, previously capitalized initial direct costs and related accumulated amortization were removed from solar energy systems, net and recorded in other non-current assets, net as incremental costs of obtaining contracts. See “—Leases” above for additional information on the effects of adopting Topic 842. System equipment costs include components such as solar panels, inverters, racking systems and other electrical equipment, as well as costs for design and installation activities once a long-term customer contract has been executed. System equipment costs are capitalized and recorded within solar energy systems, net. System equipment costs are depreciated using the straight-line method over 30 years, which is the estimated useful life of the equipment. System equipment costs are depreciated once the respective systems have been installed, interconnected to the power grid and received permission to operate. The determination of the useful lives of assets included within solar energy systems involves significant management judgment. As of December 31, 2019 and 2018, the Company had recorded costs of $1,965.2 million and $2,134.8 million in solar energy systems, of which $1,873.2 million and $1,999.3 million related to systems that had been interconnected to the power grid, with accumulated depreciation and amortization of $205.3 million and $195.9 million.
Property and Equipment, Net	Property and Equipment, Net The Company’s property and equipment is stated at cost less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method over the estimated useful lives of the assets. The right-of-use assets for vehicles leased under finance leases are amortized over the life of the lease term, which is typically three to four years. The estimated useful lives of computer equipment, furniture, fixtures and purchased software are three years. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful lives of the assets. The estimated useful lives of leasehold improvements currently range from one to 12 years. Repairs and maintenance costs are expensed as incurred. Major renewals and improvements that extend the useful lives of existing assets would be capitalized and depreciated over their estimated useful lives.
Intangible Assets	Intangible Assets The Company capitalizes costs incurred in the development of internal-use software during the application development stage. Costs related to preliminary project activities and post-implementation activities are expensed as incurred. Internal-use software is amortized on a straight-line basis over its estimated useful life, which is typically three to five years. The Company tests these assets for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. The Company recorded amortization for internal-use software of $0.1 million and $0.4 million for the years ended December 31, 2019 and 2018. The Company adopted ASU 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract Other finite-lived intangible assets, which consist of developed technology acquired in business combinations and trademarks/trade names are initially recorded at fair value and presented net of accumulated amortization. These intangible assets are amortized on a straight-line basis over their estimated useful lives. The Company amortizes trademarks/trade names over 10 years and developed technology over eight years. See Note 8—Intangible Assets.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The carrying amounts of the Company’s long-lived assets, including solar energy systems, property and equipment and finite-lived intangible assets are periodically reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of these assets may not be recoverable or that the useful life is shorter than originally estimated. Factors that the Company considers in deciding when to perform an impairment review include significant negative industry or economic trends, and significant changes or planned changes in the Company’s use of the assets. Recoverability of these assets is measured by comparison of the carrying amount of each asset to the future undiscounted cash flows the asset is expected to generate over its remaining life. If the asset is considered to be impaired, the amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. If the useful life is shorter than originally estimated, the Company amortizes the remaining carrying value over the new shorter useful life.
Other Non-Current Assets	Other Non-Current Assets See Note 7—Other Non-Current Assets for the components of other non-current assets. Capitalized costs to obtain contracts were previously considered initial direct costs and recorded within solar energy systems, net prior to the adoption of Topic 842. See “—Leases” above. Capitalized costs to obtain contracts consist of sales commissions and other customer acquisition expenses and are amortized to sales and marketing expense over the period of benefit, which is most commonly 20 years. Prepaid inventory represents payments for solar energy system components that were not delivered until the subsequent year. Operating lease right-of-use assets represent contractual rights to use assets such as offices, warehouses and related equipment in lease arrangements classified as operating leases. See Note 12—Leases. Sales incentives represent cash payments made by the Company to customers in order to finalize long-term customer contracts. Debt issuance costs represent costs incurred in connection with obtaining revolving debt financings and are deferred and amortized utilizing the straight-line method, which approximates the effective-interest method, over the term of the related financing. The Company has acquired insurance policies to mitigate the risk of ITC recapture. The insurance premiums are being amortized on a straight-line basis over the policy period. The Company provides advance payments of compensation to direct-sales personnel under certain circumstances. The advance is repaid as a reduction of the direct-sales personnel’s future compensation. The Company has established an allowance related to advances to direct-sales personnel who have terminated their employment agreement with the Company. These are non-interest-bearing advances. For Solar Lease agreements, the Company recognizes revenue on a straight-line basis over the lease term and records an asset that represents future customer payments expected to be received.
Distributions Payable to Non-Controlling Interests and Redeemable Non-Controlling Interests	Distributions Payable to Non-Controlling Interests and Redeemable Non-Controlling Interests As discussed in Note 14—Investment Funds, the Company and fund investors have formed various investment funds that the Company consolidates as the Company has determined that it is the primary beneficiary in the operational VIEs in which it has an equity interest. These VIEs are required to pay cumulative cash distributions to their respective fund investors. The Company accrues amounts payable to fund investors in distributions payable to non-controlling interests and redeemable non-controlling interests.
Deferred Revenue	Deferred Revenue Deferred revenue primarily includes cash received in advance of revenue recognition related to System Sales and rebate incentives. A portion of the cash received for System Sales is attributable to administrative services and is deferred over the period that the administrative services are provided. The majority of the cash received for System Sales is deferred until the solar energy systems are interconnected to the local power grids and receive permission to operate. Rebate incentives are received from utility companies and various government agencies and are recognized as revenue over the related customer contract term, which is most commonly 20 years. See “ —
Workmanship Accruals and Warranties	Workmanship Accruals and Warranties The Company typically warrants solar energy systems sold to customers for periods of one to ten years against defects in design and workmanship, and for periods of one to ten years that installations will remain watertight. The manufacturers’ warranties on the solar energy system components, which are typically passed through to the customers, have typical product warranty periods of 10 to 20 years and a limited performance warranty period of 25 years. The Company warrants its photovoltaic installation devices for six months to one year against defects in materials or installation workmanship. The Company generally assesses a loss contingency accrual for installation workmanship and provides for the estimated cost at the time that installation is completed. The Company assesses the workmanship accruals regularly and adjusts the amounts as necessary based on actual experience and changes in future estimates. The current portion of this accrual is recorded as a component of accrued and other current liabilities and was $4.2 million and $2.6 million as of December 31, 2019 and 2018. The non-current portion of this accrual is recorded as a component of other non-current liabilities and was $6.1 million and $3.9 million as of December 31, 2019 and 2018.
Derivative Financial Instruments	Derivative Financial Instruments The Company maintains interest rate swaps as required by the terms of its debt agreements. See Note 11—Debt Obligations. The interest rate swaps related to the Solar Asset Backed Notes, Series 2018-2 are designated as cash flow hedges. Changes in the fair value of these cash flow hedges are recorded in other comprehensive loss (“OCI”) and will subsequently be reclassified to interest expense over the life of the related debt facility as interest payments are made. As interest payments for the associated debt agreement and derivatives are recognized, the Company includes the effect of these payments in cash flows from operating activities within the consolidated statements of cash flows. The interest rate swaps related to the Warehouse Facility are not designated as hedge instruments and any changes in fair value are accounted for in other expense (income), net. Derivative instruments may be offset under their master netting arrangements. See Note 13—Derivative Financial Instruments.
Comprehensive Loss	Comprehensive Loss Comprehensive loss includes unrealized losses on the Company’s cash flow hedges and interest on derivatives recognized into earnings for the years ended December 31, 2019 and 2018.
Revenue Recognition	Revenue Recognition In accordance with Topic 606, the Company recognizes revenue according to the following steps: (1) identification of the contract with a customer, (2) identification of the performance obligations in the contract, (3) determination of the transaction price, (4) allocation of the transaction price to the performance obligations in the contract and (5) recognition of revenue when, or as, the Company satisfies a performance obligation. The Company’s revenue is composed of customer agreements and incentives, and solar energy system and product sales as captioned in the consolidated statements of operations. Customer agreements and incentives revenue includes PPA and Solar Lease revenue, solar renewable energy certificates (“SRECs”) sales and rebate incentives. Solar energy system and product sales revenue includes System Sales, which may include structural upgrades in sales contracts and SREC sales related to sold systems, and the sale of photovoltaic installation products. Revenue is recorded net of any sales tax collected. Customer Agreements and Incentives Revenue The Company enters into PPAs with residential customers, under which the customer agrees to purchase all of the power generated by the solar energy system for the term of the contract, which is most commonly 20 years. The agreement includes a fixed price per kilowatt hour with a fixed annual price escalation percentage. Customers have not historically been charged for installation or activation of the solar energy system. For all PPAs, the Company assesses the probability of collectability on a customer-by-customer basis through a credit review process that evaluates their financial condition and ability to pay. PPA revenue is recognized based on the actual amount of power generated at rates specified under the contracts. The Company also offers solar energy systems to customers pursuant to Solar Leases in certain markets. The customer agreements are structured as Solar Leases due to local regulations that can be read to prohibit the sale of electricity pursuant to the Company’s standard PPA. Pursuant to Solar Leases, the customers’ monthly payments are a pre-determined amount calculated based on the expected solar energy generation by the system and typically have included an annual fixed percentage price escalation over the period of the contracts, which is most commonly 20 years, though some markets offer Solar Leases with no annual price escalation. Revenue from Solar Leases is recognized on a straight-line basis over the contractual term. The Company records a straight-line Solar Lease asset in other non-current assets, net, which represents revenue recognized in advance of customer payments. The Company provides its Solar Lease customers a performance guarantee, under which the Company agrees to refund certain payments at the end of each year to the customer if the solar energy system does not meet a guaranteed production level in the prior 12-month period. The guaranteed production levels have varying terms. Solar energy performance guarantee liabilities were $0.5 million and $0.2 million as of December 31, 2019 and 2018. Solar energy performance guarantees are recognized as contra-revenue in the period in which the liabilities are recorded. At times the Company makes nominal cash payments to customers in order to facilitate the finalization of long-term customer contracts and the installation of related solar energy systems. These sales incentives are deferred and recognized over the term of the contract as a reduction of revenue. The Company applies for and receives SRECs in certain jurisdictions for power generated by solar energy systems it has installed. When SRECs are granted, the Company typically sells them to other companies directly, or to brokers, to assist them in meeting their own mandatory emission reduction or conservation requirements. The Company recognizes revenue related to the sale of these certificates upon delivery, assuming the other revenue recognition criteria discussed above are met. Total SREC revenue was $48.4 million and $44.1 million for the years ended December 31, 2019 and 2018. Solar Energy System and Product Sales The Company’s principal performance obligation for System Sales is to design and install a solar energy system that is interconnected to the local power grid and granted permission to operate. When the solar energy system has been granted permission to operate, the customer retains all of the significant risks and rewards of ownership of the solar energy system. For certain System Sales, the Company provides limited post-sale services to monitor the productivity of the solar energy system for 20 years after it has been placed in service. The Company collects cash during the installation process and recognizes revenue for System Sales and other product sales at the placed in-service date or product delivery date less any revenue allocated to monitoring services. The Company allocates a portion of the transaction price to the monitoring services by estimating the fair market price that the Company would charge for these services if offered separately from the sale of the solar energy system. As of December 31, 2019 and 2018, the Company had allocated deferred revenue of $4.7 million and $3.3 million to monitoring services that will be recognized over the term of the monitoring services. All costs to obtain and fulfill contracts associated with System Sales and other product sales are expensed as a cost of revenue when the Company has fulfilled its performance obligation and the products have been placed into service or delivered to the customer.
Cost of Revenue	Cost of Revenue Cost of Revenue—Customer Agreements and Incentives Cost of revenue—customer agreements and incentives includes the depreciation of the cost of solar energy systems under long-term customer contracts. It also includes allocated indirect material and labor costs related to the processing; account creation; design; installation; interconnection and servicing of solar energy systems that are not capitalized, such as personnel costs not directly associated to a solar energy system installation; warehouse rent and utilities; and fleet vehicle executory costs. The cost of customer agreements and incentives also includes allocated facilities and information technology costs. The cost of revenue for the sales of SRECs is limited to broker fees which are paid in connection with certain SREC transactions. Cost of Revenue—Solar Energy System and Product Sales Cost of revenue—solar energy system and product sales consists of direct and allocated indirect material and labor costs for System Sales, photovoltaic installation products and structural upgrades. Indirect material and labor costs are ratably allocated to System Sales and include costs related to the processing; account creation; design; installation; interconnection and servicing of solar energy systems, such as personnel costs not directly associated to a solar energy system installation; warehouse rent and utilities; and fleet vehicle executory costs. The cost of solar energy system and product sales also includes allocated facilities and information technology costs. Costs of solar energy system sales are recognized in conjunction with the related revenue upon the solar energy system passing an inspection by the responsible governmental department after completion of system installation and interconnection to the local power grid.
Advertising Costs	Advertising Costs Advertising costs are expensed when incurred and are included in sales and marketing expenses in the consolidated statements of operations. The Company’s advertising costs were $4.4 million and $3.6 million for the years ended December 31, 2019 and 2018.
Vivint Related Party Expenses	Vivint Related Party Expenses The Company has a sales dealer agreement with Vivint Smart Home, Inc. (“Vivint”), pursuant to which each company will act as a non-exclusive dealer for the other party to market. The fees under this agreement were allocated to the Company on a basis that was considered to reasonably reflect the utilization of the services provided to, or the benefit obtained by, the Company. For additional information, see Note 18—Related Party Transactions.
Other Expense (Income), Net	Other Expense (Income), Net For the year ended December 31, 2019, other expense (income), net primarily includes changes in fair value for the Company’s interest rate swaps not designated as hedges. For the year ended December 31, 2018, other expense (income), net primarily includes changes in fair value for the Company’s interest rate swaps not designated as hedges and a payment received as an initial distribution on one of the Company’s legal proceedings. Changes in the fair value of the Company’s interest rate swaps are recorded in other expense (income), net each reporting period when the interest rate swaps are marked to market.
Provision for Income Taxes	Provision for Income Taxes The Company accounts for income taxes under an asset and liability approach. Deferred income taxes are classified as long-term and reflect the impact of temporary differences between assets and liabilities recognized for financial reporting purposes and the amounts recognized for income tax reporting purposes, net operating loss carryforwards, and other tax credits measured by applying currently enacted tax laws. A valuation allowance is provided when necessary to reduce deferred tax assets to an amount that is more likely than not to be realized. As required by ASC 740, the Company recognizes the effect of tax rate and law changes on deferred taxes in the reporting period in which the legislation is enacted. The Company determines whether a tax position is more likely than not to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. The Company uses a two-step approach to recognize and measure uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained upon tax authority examination, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon ultimate settlement. The Company’s policy is to include interest and penalties related to unrecognized tax benefits, if any, within income tax expense. The Company sells solar energy systems to the investment funds for income tax purposes. As the investment funds are consolidated by the Company, the gain on the sale of the solar energy systems is eliminated in the consolidated financial statements. However, this gain is recognized for tax reporting purposes. The Company accounts for the income tax consequences of these intra-entity transfers, both current and deferred, as a component of income tax expense and deferred tax liability, net during the period in which the transfers occur. The Company’s policy is to include interest and penalties related to unrecognized tax benefits, if any, within income tax expense. The Company recognizes income tax effects directly to continuing operations and accumulated other comprehensive loss (“AOCI”) pursuant to applicable intraperiod allocation rules. The Company’s policy is to release income tax effects from AOCI using an item-by-item approach when the circumstances upon which they are premised cease to exist.
Stock-Based Compensation Expense	Stock-Based Compensation Expense Stock-based compensation expense for equity instruments issued to employees is measured based on the grant-date fair value of the awards. The fair value of each restricted stock unit is determined as the closing price of the Company’s stock on the date of grant. The fair value of each time-based employee stock option is estimated on the date of grant using the Black-Scholes-Merton stock option pricing valuation model. The Company recognizes compensation costs using the accelerated attribution method for all time-based equity compensation awards over the requisite service period of the awards, which is generally the awards’ vesting period. For performance-based equity compensation awards, the Company generally recognizes compensation expense for each vesting tranche over the related performance period.
Post-Employment Benefits	Post-Employment Benefits The Company sponsors a 401(k) Plan that covers all of the Company’s eligible employees. In 2019, the Company matched 33% of each employee’s contributions up to a maximum of 6% of the employee’s eligible earnings. The Company recorded expense related to this match of $1.4 million for the year ended December 31, 2019. Prior to 2019, the Company did not provide a discretionary company match to employee contributions.
Non-Controlling Interests and Redeemable Non-Controlling Interests	Non-Controlling Interests and Redeemable Non-Controlling Interests Non-controlling interests and redeemable non-controlling interests represent fund investors’ interests in the net assets of certain consolidated investment funds, which have been entered into by the Company in order to finance the costs of solar energy systems under long-term customer contracts. The Company has determined that the provisions in the contractual arrangements represent substantive profit-sharing arrangements, which gives rise to the non-controlling interests and redeemable non-controlling interests. The Company has further determined that the appropriate methodology for attributing income and loss to the non-controlling interests and redeemable non-controlling interests each period is a balance sheet approach referred to as the hypothetical liquidation at book value (“HLBV”) method. Under the HLBV method, the amounts of income and loss attributed to the non-controlling interests and redeemable non-controlling interests in the consolidated statements of operations reflect changes in the amounts the fund investors would hypothetically receive at each balance sheet date under the liquidation provisions of the contractual agreements of these structures, assuming the net assets of these funding structures were liquidated at recorded amounts. The fund investors’ non-controlling interest in the results of operations of these funding structures is determined as the difference in the non-controlling interests’ and redeemable non-controlling interests’ claims under the HLBV method at the start and end of each reporting period, after considering any capital transactions, such as contributions or distributions, between the fund and the fund investors. Attributing income and loss to the non-controlling interests and redeemable non-controlling interests under the HLBV method requires the use of significant assumptions and estimates to calculate the amounts that fund investors would receive upon a hypothetical liquidation. Changes in these assumptions and estimates can have a significant impact on the amount that fund investors would receive upon a hypothetical liquidation. The use of the HLBV methodology to allocate income to the non-controlling and redeemable non-controlling interest holders may create volatility in the Company’s consolidated statements of operations as the application of HLBV can drive changes in net income available and loss attributable to non-controlling interests and redeemable non-controlling interests from quarter to quarter. The Company classifies certain non-controlling interests with redemption features that are not solely within the control of the Company outside of permanent equity on its consolidated balance sheets. Estimated redemption value is calculated as the discounted cash flows subsequent to the expected flip date of the respective investment funds. Redeemable non-controlling interests are reported using the greater of their carrying value at each reporting date as determined by the HLBV method or their estimated redemption value in each reporting period. Estimating the redemption value of the redeemable non-controlling interests requires the use of significant assumptions and estimates. Changes in these assumptions and estimates can have a significant impact on the calculation of the redemption value.
Loss Contingencies	Loss Contingencies The Company is subject to the possibility of various loss contingencies arising in the ordinary course of business. The Company considers the likelihood of loss or impairment of an asset, or the incurrence of a liability, as well as the Company’s ability to reasonably estimate the amount of loss, in determining loss contingencies. An estimated loss contingency is accrued when it is probable that an asset has been impaired or a liability has been incurred and the amount of loss can be reasonably estimated. The Company regularly evaluates current information available to determine whether an accrual is required, an accrual should be adjusted or a range of possible loss should be disclosed.
Segment Information	Segment Information The Company’s chief operating decision maker is its chief executive officer. The chief executive officer reviews financial information for purposes of allocating resources and evaluating financial performance. The Company has one business activity, providing solar energy services and products to customers. Accordingly, the Company has a single operating and reporting segment.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Comparison on Effects of Adopting Topic 842	For purposes of comparison, the following tables show how the balances as of December 31, 2018 and for the year ended December 31, 2018 would have changed if the effects of adopting Topic 842 had been applied to those balances (in thousands): December 31, 2018 December 31, 2019 As Reported Adjustments As Adjusted As Reported Solar energy systems, net $ 1,938,874 $ (388,087 ) $ 1,550,787 $ 1,759,861 Other non-current assets, net 28,090 388,087 416,177 680,062 Year Ended December 31, 2018 2019 As Reported Adjustments As Adjusted As Reported Cost of revenue—customer agreements and incentives $ 164,920 $ (18,164 ) $ 146,756 $ 186,325 Cost of revenue—solar energy system and product sales 83,375 (19,060 ) 64,315 72,221 Total cost of revenue 248,295 (37,224 ) 211,071 258,546 Gross profit 42,026 37,224 79,250 82,495 Sales and marketing 58,950 37,224 96,174 151,194 Total operating expenses 154,520 37,224 191,744 271,059

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis	The following tables set forth the fair value of the Company’s financial assets and liabilities included on the consolidated balance sheets measured on a recurring basis by level within the fair value hierarchy (in thousands): December 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets Interest rate swaps $ — $ 3,245 $ — $ 3,245 Financial Liabilities Interest rate swaps $ — $ 28,070 $ — $ 28,070 December 31, 2018 Level 1 Level 2 Level 3 Total Financial Assets Interest rate swaps $ — $ 130 $ — $ 130 Financial Liabilities Interest rate swaps $ — $ 11,146 $ — $ 11,146
Schedule of Carrying Values and Fair Values of Company's Long-term Debt	The carrying values and fair values of the Company’s long-term debt were as follows (in thousands): December 31, 2019 December 31, 2018 Carrying Value Fair Value Carrying Value Fair Value Floating-rate long-term debt $ 894,907 $ 894,907 $ 587,358 $ 587,358 Fixed-rate long-term debt 629,908 702,895 653,031 673,917 Subtotal long-term debt 1,524,815 $ 1,597,802 1,240,389 $ 1,261,275 Unamortized debt issuance costs (25,154 ) (24,952 ) Total long-term debt $ 1,499,661 $ 1,215,437

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2019
Inventory Disclosure [Abstract]
Summary of Inventories	Inventories consisted of the following (in thousands): December 31, December 31, 2019 2018 Solar energy systems held for sale $ 19,892 $ 12,321 Photovoltaic installation products 684 936 Total inventories $ 20,576 $ 13,257

Solar Energy Systems (Tables)

Solar Energy Systems (Tables)	12 Months Ended
	Dec. 31, 2019
Solar Energy Systems Disclosure [Abstract]
Solar Energy Systems	Solar energy systems, net consisted of the following (in thousands): December 31, December 31, 2019 2018 System equipment costs $ 1,926,809 $ 1,667,440 Initial direct costs related to solar energy systems — 435,084 1,926,809 2,102,524 Less: Accumulated depreciation and amortization (205,338 ) (195,890 ) 1,721,471 1,906,634 Solar energy system inventory 38,390 32,240 Solar energy systems, net $ 1,759,861 $ 1,938,874

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Summary of Property and Equipment Net	Property and equipment, net consisted of the following (in thousands): Estimated December 31, December 31, Useful Lives 2019 2018 Leasehold improvements 1-12 years $ 10,458 $ 10,560 Vehicles acquired under finance leases 3-4 years 10,280 6,907 Furniture and computer and other equipment 3-5 years 5,021 3,816 25,759 21,283 Less: Accumulated depreciation and amortization (8,259 ) (10,553 ) Property and equipment, net $ 17,500 $ 10,730

Other Non-Current Assets (Table

Other Non-Current Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Other Assets Noncurrent Disclosure [Abstract]
Schedule of Other Non-Current Assets	Other non-current assets consisted of the following (in thousands): December 31, December 31, 2019 2018 Costs to obtain contracts $ 615,385 $ — Accumulated amortization of costs to obtain contracts (70,170 ) — Prepaid inventory 50,104 — Operating lease right-of-use assets 39,118 — Sales incentives 10,008 8,588 Debt issuance costs 9,936 2,415 Prepaid insurance 6,541 6,890 Advances receivable from sales professionals 6,395 5,109 Solar Lease straight-line asset 5,722 3,402 Other non-current assets 7,023 1,686 Total other non-current assets $ 680,062 $ 28,090

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Net Intangible Assets Included in Other Non Current assets , Net	Net intangible assets are included in other non-current assets, net and consisted of the following (in thousands): December 31, December 31, 2019 2018 Cost: Internal-use software $ 2,596 $ 1,020 Developed technology 522 522 Trademarks/trade names 201 201 Total carrying value 3,319 1,743 Accumulated amortization: Internal-use software (105 ) (781 ) Developed technology (393 ) (324 ) Trademarks/trade names (119 ) (99 ) Total accumulated amortization (617 ) (1,204 ) Total intangible assets, net $ 2,702 $ 539
Summary of Expected Amortization Expense	As of December 31, 2019, expected amortization expense for the unamortized intangible assets was as follows (in thousands): Years Ending December 31, 2020 $ 635 2021 605 2022 495 2023 492 2024 475 Thereafter — Total $ 2,702

Accrued Compensation (Tables)

Accrued Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Accrued Compensation Disclosure [Abstract]
Summary of Accrued Compensation	Accrued compensation consisted of the following (in thousands): December 31, December 31, 2019 2018 Accrued payroll $ 18,633 $ 16,352 Accrued commissions 15,516 9,168 Total accrued compensation $ 34,149 $ 25,520

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2019
Payables And Accruals [Abstract]
Schedule of Accrued and Other Current Liabilities	Accrued and other current liabilities consisted of the following (in thousands): December 31, December 31, 2019 2018 Accrued unused commitment fees and interest $ 16,995 $ 14,102 Litigation settlement 12,780 100 Current portion of operating lease liabilities 8,436 — Accrued workers' compensation 7,166 4,033 Accrued professional fees 5,546 6,150 Current portion of lease pass-through financing obligation 5,147 5,038 Accrued inventory 4,667 4,380 Sales, use and property taxes payable 4,321 3,132 Workmanship accrual 4,217 2,630 External customer experience services 1,984 — Other accrued expenses 7,280 3,295 Total accrued and other current liabilities $ 78,539 $ 42,860

Debt Obligations (Tables)

Debt Obligations (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Debt	Debt obligations consisted of the following as of December 31, 2019 (in thousands, except interest rates): Principal Unamortized Debt Unused Borrowings Issuance Costs Net Carrying Value Borrowing Interest Maturity Outstanding Current Long-term Current Long-term Capacity Rate Date Solar asset backed notes, Series 2018-1 (1) $ 448,277 $ (69 ) $ (8,414 ) $ 3,639 $ 436,155 $ — 5.1 % October 2028 Solar asset backed notes, Series 2018-2 (2)(3) 338,294 (5 ) (6,133 ) 1,245 330,911 — 5.5 August 2023 2017 Term loan facility 180,365 (164 ) (4,235 ) 7,882 168,084 — 6.0 January 2035 2018 Forward flow loan facility 124,800 (99 ) (3,083 ) 3,622 117,996 — 4.7 November 2039 2019 Forward flow loan facility 82,813 — (2,857 ) — 79,956 67,187 4.7 (4) Credit agreement 1,266 (2 ) (93 ) 17 1,154 — 6.5 February 2023 Revolving lines of credit (5) Warehouse facility 250,000 — — — 250,000 75,000 4.3 August 2023 Asset Financing Facility (6) 99,000 — — — 99,000 81,362 5.2 June 2023 Total debt $ 1,524,815 $ (339 ) $ (24,815 ) $ 16,405 $ 1,483,256 $ 223,549 Debt obligations consisted of the following as of December 31, 2018 (in thousands, except interest rates): Principal Unamortized Debt Unused Borrowings Issuance Costs Net Carrying Value Borrowing Interest Maturity Outstanding Current Long-term Current Long-term Capacity Rate Date Solar asset backed notes, Series 2018-1 (1) $ 462,826 $ (74 ) $ (9,172 ) $ 3,655 $ 449,925 $ — 5.1 % October 2028 Solar asset backed notes, Series 2018-2 (2)(3) 342,833 (6 ) (7,388 ) 294 335,145 — 5.4 August 2023 2017 Term loan facility 188,922 (170 ) (4,614 ) 6,679 177,459 — 6.0 January 2035 2018 Forward flow loan facility 58,425 (43 ) (3,365 ) 1,512 53,505 71,575 5.2 November 2039 Credit agreement 1,283 (2 ) (118 ) 15 1,148 — 6.5 February 2023 Revolving lines of credit (5) Aggregation facility 50,000 — — — 50,000 325,000 5.7 September 2020 Working capital facility (6) 136,100 — — — 136,100 — 5.6 March 2020 Total debt $ 1,240,389 $ (295 ) $ (24,657 ) $ 12,155 $ 1,203,282 $ 396,575 (1) The interest rate disclosed in the table above is a weighted-average rate. The Series 2018-1 Notes are composed of Class A and Class B Notes. Class A Notes accrue interest at 4.73%. Class B Notes accrue interest at 7.37%. (2) The Series 2018-2 Notes are composed of Class A and Class B Notes. Class B Notes accrue interest at a rate of LIBOR plus 4.75%. Class A Notes accrue interest at a variable spread over LIBOR that results in a weighted average spread for all 2018-2 Notes of 2.95%. (3) The interest rate of this facility is partially hedged to an effective interest rate of 6.0% for $323.6 million of the principal borrowings. See Note 13—Derivative Financial Instruments. (4) The maturity date for this facility is 20 years from the end date of the borrowing availability period when all borrowings are aggregated into one term loan, which will be no later than November 20, 2020. (5) Revolving lines of credit are not presented net of unamortized debt issuance costs. (6) Facility is recourse debt, which refers to debt that is collateralized by the Company’s general assets. All of the Company’s other debt obligations are non-recourse, which refers to debt that is only collateralized by specified assets or subsidiaries of the Company.
Scheduled Maturities of Debt	The scheduled maturities of debt as of December 31, 2019 are as follows (in thousands): 2020 $ 14,425 2021 15,803 2022 21,065 2023 704,801 2024 28,908 Thereafter 739,813 Total $ 1,524,815

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Lessee Disclosure [Abstract]
Summary of Lease Costs and Other Information	Lease costs and other information consisted of the following (in thousands, except terms and rates): Year Ended December 31, 2019 Lease cost Finance lease cost: Amortization of right-of-use assets $ 1,758 Interest on lease liabilities 326 Operating lease cost 11,329 Short-term lease cost 2,069 Total lease cost $ 15,482 Other information Finance leases: Operating cash outflows from finance leases $ 326 Financing cash outflows from finance leases $ 1,480 Right-of-use assets obtained in exchange for new finance lease liabilities $ 9,482 Weighted-average remaining lease term - finance leases (in years) 3.6 Weighted-average discount rate - finance leases 7.2 % Operating leases: Operating cash outflows from operating leases $ 11,460 Right-of-use assets obtained in exchange for new operating lease liabilities $ 12,217 Weighted-average remaining lease term - operating leases (in years) 8.9 Weighted-average discount rate - operating leases 8.0 %
Schedule of Future Minimum Lease Payments for Finance Leases	Future minimum lease payments for the Company’s finance leases as of December 31, 2019 were as follows (in thousands): 2020 $ 2,806 2021 2,775 2022 2,649 2023 1,607 2024 — Thereafter — Total minimum lease payments 9,837 Less: interest 1,120 Present value of finance lease obligations 8,717 Less: current portion 2,274 Long-term portion $ 6,443
Schedule of Future Minimum Lease Payments Under Non-cancellable Operating Leases	Future minimum lease payments under non-cancellable operating leases as of December 31, 2019 were as follows (in thousands): 2020 $ 11,883 2021 8,779 2022 6,481 2023 5,038 2024 4,803 Thereafter 31,877 Total minimum lease payments 68,861 Less: present value impact 20,704 Present value of operating lease obligations 48,157 Less: current portion 8,436 Long-term portion $ 39,721

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Schedule of Derivative Financial Instruments at Fair Value	Derivative financial instruments at fair value consisted of the following (in thousands): December 31, 2019 Fair Value Balance Sheet Location Derivatives designated as hedging instruments: Interest rate swaps $ 28,070 Other non-current liabilities Derivatives not designated as hedging instruments: Interest rate swaps $ 3,245 Other non-current assets December 31, 2018 Fair Value Balance Sheet Location Derivatives designated as hedging instruments: Interest rate swaps $ 9,884 Other non-current liabilities Derivatives not designated as hedging instruments: Interest rate swaps $ 1,262 Other non-current liabilities Interest rate swaps $ 130 Other non-current assets
Schedule of Losses (Gains) on Derivative Financial Instruments Recognized in OCI and Condensed Consolidated Statements of Operations Before Tax Effect	The losses on derivatives designated as cash flow hedges recognized in OCI, before tax effect, consisted of the following (in thousands): Year Ended December 31, 2019 2018 Derivatives designated as cash flow hedges: Interest rate swaps $ 19,653 $ 2,311 Year Ended December 31, 2019 2018 Interest expense, net Other expense (income), net Interest expense, net Other expense (income), net Total amounts presented in the income statement line items $ 82,323 $ 1,434 $ 65,308 $ (4,538 ) Derivatives designated as cash flow hedges: Interest rate swaps Losses (gains) reclassified from AOCI into income $ 1,467 $ — $ (21,601 ) $ — Derivatives not designated as hedging instruments: Interest rate swaps Losses (gains) recognized in income — 1,433 — (2,420 ) Total losses (gains) $ 1,467 $ 1,433 $ (21,601 ) $ (2,420 )

Investment Funds (Tables)

Investment Funds (Tables)	12 Months Ended
	Dec. 31, 2019
Schedule Of Investments [Abstract]
Aggregate Carrying Value of Funds Assets and Liabilities	The Company has formed investment funds for the purpose of funding the purchase of solar energy systems under long-term customer contracts. As of December 31, 2019, and 2018, the aggregate carrying value of these funds’ assets and liabilities (after elimination of intercompany transactions and balances) in the Company’s consolidated balance sheets were as follows (in thousands): December 31, December 31, 2019 2018 Assets Current assets: Cash and cash equivalents $ 82,764 $ 62,350 Accounts receivable, net 8,922 6,593 Prepaid expenses and other current assets 1,676 1,289 Total current assets 93,362 70,232 Restricted cash and cash equivalents 8,890 2,443 Solar energy systems, net 1,587,354 1,752,271 Other non-current assets, net 504,668 10,888 Total assets $ 2,194,274 $ 1,835,834 Liabilities Current liabilities: Distributions payable to non-controlling interests and redeemable non-controlling interests $ 10,253 $ 7,846 Current portion of long-term debt 3,622 1,512 Current portion of deferred revenue 2,590 2,320 Accrued and other current liabilities 6,394 4,860 Total current liabilities 22,859 16,538 Long-term debt, net of current portion 197,952 53,505 Deferred revenue, net of current portion 12,242 9,694 Other non-current liabilities 301 1,023 Total liabilities $ 233,354 $ 80,760

Redeemable Non-Controlling In_2

Redeemable Non-Controlling Interests and Equity and Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2019
Noncontrolling Interest [Abstract]
Schedule of Shares of Common Stock Reserved for Issuance	The Company had shares of common stock reserved for issuance as follows (in thousands): December 31, December 31, 2019 2018 Shares available for grant under equity incentive plans 13,060 13,323 Restricted stock units issued and outstanding 6,271 6,172 Stock options issued and outstanding 5,421 3,394 Long-term incentive plan 2,706 2,706 Total 27,458 25,595

Equity Compensation Plans (Tabl

Equity Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	Stock option activity for the year ended December 31, 2019 was as follows (in thousands, except term and per share amounts): Weighted- Weighted- Average Shares Average Remaining Aggregate Underlying Exercise Contractual Intrinsic Options Price Term (in years) Value Outstanding—December 31, 2018 3,394 $ 2.77 $ 4,689 Granted 2,674 5.60 Exercised (578 ) 1.73 Cancelled (69 ) 7.53 Outstanding—December 31, 2019 5,421 $ 4.21 7.8 $ 17,073 Options vested and exercisable—December 31, 2019 1,989 $ 2.65 5.7 $ 9,551
Weighted Average Assumptions to Estimate Fair Value of Stock Options	The fair values using the Black-Scholes-Merton method were estimated on each grant date using the following weighted-average assumptions: Year Ended December 31, 2019 2018 Expected term (in years) 6.3 6.2 Volatility 67.8 % 70.7 % Risk-free interest rate 2.3 % 2.8 % Dividend yield 0.0 % 0.0 %
RSU Activity	RSU activity for the year ended December 31, 2019 was as follows (awards in thousands): Weighted- Average Number of Grant Date Awards Fair Value Outstanding at December 31, 2018 6,172 $ 3.84 Granted 3,130 6.01 Vested (2,364 ) 3.83 Forfeited (667 ) 4.51 Outstanding at December 31, 2019 6,271 $ 4.85
Summary of Stock-Based Compensation Expense	Stock-based compensation was included in operating expenses as follows (in thousands): Year Ended December 31, 2019 2018 Cost of revenue $ 1,653 $ 1,333 Sales and marketing 3,305 3,353 General and administrative 11,330 8,344 Research and development 130 133 Total stock-based compensation $ 16,418 $ 13,163
Summary of Unrecognized Stock-Based Compensation Expense	Unrecognized stock-based compensation expense for time-based stock options and RSUs as of December 31, 2019 was as follows (in thousands, except years): Unrecognized Weighted- Stock-Based Average Period Compensation of Recognition Expense (in years) RSUs $ 18,726 1.7 Stock options 7,073 2.0 Total unrecognized stock-based compensation expense $ 25,799

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense	Income tax expense is composed of the following (in thousands): Year Ended December 31, 2019 2018 Current: Federal $ (711 ) $ (665 ) State 162 102 Total current benefit (549 ) (563 ) Deferred: Federal 101,965 79,048 State 49,583 27,814 Total deferred expense 151,548 106,862 Income tax expense $ 150,999 $ 106,299
Schedule of Reconciliation on Income Tax Benefit Computed at Statutory Federal Rate and Income Tax Expense	The following table presents a reconciliation of the income tax benefit computed at the statutory federal rate and the Company’s income tax expense (in thousands): Year Ended December 31, 2019 2018 Income tax benefit—computed as 21% of pretax loss $ (57,187 ) $ (36,385 ) Effect of non-controlling interests and redeemable non-controlling interests 67,440 55,434 State and local income tax expenses (net of federal benefit) 39,299 22,054 Tax gains on sale of solar energy systems to investment funds 103,689 68,683 Effect of tax credits (2,781 ) (2,684 ) Other 539 (803 ) Income tax expense $ 150,999 $ 106,299
Schedule of Deferred Tax Assets and Liabilities	Deferred income taxes reflect the impact of temporary differences between assets and liabilities for financial reporting purposes and the amounts recognized for income tax reporting purposes, net operating loss carryforwards and other tax credits. The differences are measured by applying currently enacted tax laws. The significant components of the Company’s deferred tax assets and liabilities were as follows (in thousands): December 31, 2019 2018 Deferred tax assets: Accruals and reserves $ 13,719 $ 6,552 Stock-based compensation 5,698 4,204 Investment tax and other credits 51,721 49,194 Net operating losses 16,218 13,662 Interest rate swaps 6,752 2,982 Other 411 1,149 Gross deferred tax assets 94,519 77,743 Valuation allowance (314 ) (306 ) Net deferred tax assets 94,205 77,437 Deferred tax liabilities: Investment in solar funds (648,267 ) (483,522 ) Fixed asset depreciation and amortization (29,633 ) (31,035 ) Gross deferred tax liabilities (677,900 ) (514,557 ) Net deferred tax liabilities $ (583,695 ) $ (437,120 )
Aggregate Changes in Balance of Gross Unrecognized Tax Benefits	The aggregate changes in the balance of gross unrecognized tax benefits, which excludes interest and penalties, for the years ended December 31, 2019 and 2018, is as follows (in thousands): Year Ended December 31, 2019 2018 Beginning balance $ 555 $ — Increases related to positions from a prior year 230 447 Increases related to positions from the current year 172 108 Ending balance $ 957 $ 555

Basic and Diluted Net Loss Pe_2

Basic and Diluted Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Loss Per Share to Common Stockholders	The following table sets forth the computation of the Company’s basic and diluted net loss attributable per share to common stockholders for the years ended December 31, 2019 and 2018 (in thousands, except per share amounts): Year Ended December 31, 2019 2018 Numerator: Net loss attributable to common stockholders $ (102,175 ) $ (15,592 ) Denominator: Shares used in computing net loss attributable per share to common stockholders, basic and diluted 121,310 117,565 Net loss attributable per share to common stockholders: Basic and diluted $ (0.84 ) $ (0.13 )
Schedule of Shares Excluded from Computation of Net Loss Per Share	The following table contains share totals with a potentially dilutive impact (in thousands): Year Ended December 31, 2019 2018 Restricted stock units 6,271 6,172 Stock options 5,421 3,394 Total 11,692 9,566

Organization - Additional Infor

Organization - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Contractual term of customers	20 years

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Details)	Jan. 01, 2019USD ($)	Dec. 31, 2019USD ($)SupplierSegment	Dec. 31, 2018USD ($)
Summary Of Significant Accounting Policies [Line Items]
Restricted cash		$ 89,892,000	$ 71,305,000
Allowance for doubtful accounts receivable		$ 9,400,000	5,200,000
ITC as percentage of value of eligible solar property		30.00%
Operating leases right-of-use assets		$ 39,118,000
Operating leases lease liabilities		$ 48,157,000
Operating leases liabilities removed from current liabilities	$ 1,000,000
Property and Equipment, Estimated Useful Lives		30 years
Solar energy systems, gross		$ 1,926,809,000	2,102,524,000
Accumulated depreciation and amortization		$ 205,338,000	195,890,000
Cost to obtain contracts amortized term		20 years
Accrued installation and workmanship reserves, current		$ 4,200,000	2,600,000
Accrued installation and workmanship reserves, non current		$ 6,100,000	3,900,000
Contractual term of customers		20 years
Advertising costs		$ 4,400,000	3,600,000
Percentage of tax benefit realized upon ultimate settlement		50.00%
Number of reporting segments | Segment		1
Number of operating segments | Segment		1
401(k) Plan
Summary Of Significant Accounting Policies [Line Items]
Percentage match of employee contribution under 401(k) plan		33.00%
Defined contribution plan, expense		$ 1,400,000
Sales and Marketing
Summary Of Significant Accounting Policies [Line Items]
Impairment of long lived assets write off charges		600,000
Internal-use software
Summary Of Significant Accounting Policies [Line Items]
Amortization of internal-use software		$ 100,000	400,000
Trademarks/Trade Names
Summary Of Significant Accounting Policies [Line Items]
Amortization period of intangible assets		10 years
Developed Technology
Summary Of Significant Accounting Policies [Line Items]
Amortization period of intangible assets		8 years
Furniture and Computer and Other Equipment
Summary Of Significant Accounting Policies [Line Items]
Property and Equipment, Estimated Useful Lives		3 years
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit	200,000
Short term leases right of use asset	0
Short term lease liability	0
Operating leases right-of-use assets	34,600,000
Operating leases lease liabilities	43,800,000
Operating leases liabilities removed from non current liabilities	8,200,000
Finance lease right-of-use assets	$ 900,000
Solar Energy Systems
Summary Of Significant Accounting Policies [Line Items]
Solar energy systems, gross		$ 1,965,200,000	2,134,800,000
Limited performance warranty period		25 years
Performance guarantee liabilities		$ 500,000	200,000
Power Grid
Summary Of Significant Accounting Policies [Line Items]
Solar energy systems, gross		1,873,200,000	1,999,300,000
Customer Agreements and Incentives
Summary Of Significant Accounting Policies [Line Items]
Impairment of long lived assets write off charges		3,400,000
Solar Renewable Energy Certificates
Summary Of Significant Accounting Policies [Line Items]
Operating leases and incentives		48,400,000	44,100,000
Monitoring Services
Summary Of Significant Accounting Policies [Line Items]
Deferred revenue		$ 4,700,000	$ 3,300,000
Accounts Receivable , Net | Customers | Solar energy system sales
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		48.00%
Concentration risk amount		$ 11,600,000
Cost of Goods Product Line | Solar Photovoltaic Module Purchases
Summary Of Significant Accounting Policies [Line Items]
Number of suppliers | Supplier		2
Cost of Goods Product Line | Inverter Purchases
Summary Of Significant Accounting Policies [Line Items]
Number of suppliers | Supplier		2
Cost of Goods Product Line | Customers | Megawatts Installed | California
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		46.00%	38.00%
Cost of Goods Product Line | Customers | Megawatts Installed | Northeastern United States
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		26.00%	32.00%
Cost of Goods Product Line | Supplier One | Solar Photovoltaic Module Purchases
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		91.00%
Cost of Goods Product Line | Supplier Two | Solar Photovoltaic Module Purchases
Summary Of Significant Accounting Policies [Line Items]
Concentration risk percentage		91.00%
Required Reserves
Summary Of Significant Accounting Policies [Line Items]
Restricted cash		$ 79,900,000
Minimum
Summary Of Significant Accounting Policies [Line Items]
Restricted cash		$ 10,000,000	$ 10,000,000
Product warranty period against defects in design and workmanship		1 year
Warranty period		1 year
Minimum | Internal-use software
Summary Of Significant Accounting Policies [Line Items]
Amortization period of intangible assets		3 years
Minimum | Right-of-Use Assets Vehicles Leased Under Finance Leases
Summary Of Significant Accounting Policies [Line Items]
Property and Equipment, Estimated Useful Lives		3 years
Minimum | Furniture and Computer and Other Equipment
Summary Of Significant Accounting Policies [Line Items]
Property and Equipment, Estimated Useful Lives		3 years
Minimum | Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Property and Equipment, Estimated Useful Lives		1 year
Minimum | Solar Energy Systems | Product Warranty
Summary Of Significant Accounting Policies [Line Items]
Warranty period		10 years
Minimum | Photovoltaic Installation Software Products and Devices
Summary Of Significant Accounting Policies [Line Items]
Warranty period		6 months
Maximum
Summary Of Significant Accounting Policies [Line Items]
Product warranty period against defects in design and workmanship		10 years
Warranty period		10 years
Maximum | 401(k) Plan
Summary Of Significant Accounting Policies [Line Items]
Maximum contribution match by the employer as a percentage of employee compensation		6.00%
Maximum | Internal-use software
Summary Of Significant Accounting Policies [Line Items]
Amortization period of intangible assets		5 years
Maximum | Right-of-Use Assets Vehicles Leased Under Finance Leases
Summary Of Significant Accounting Policies [Line Items]
Property and Equipment, Estimated Useful Lives		4 years
Maximum | Furniture and Computer and Other Equipment
Summary Of Significant Accounting Policies [Line Items]
Property and Equipment, Estimated Useful Lives		5 years
Maximum | Leasehold Improvements
Summary Of Significant Accounting Policies [Line Items]
Property and Equipment, Estimated Useful Lives		12 years
Maximum | Solar Energy Systems | Product Warranty
Summary Of Significant Accounting Policies [Line Items]
Warranty period		20 years
Maximum | Photovoltaic Installation Software Products and Devices
Summary Of Significant Accounting Policies [Line Items]
Warranty period		1 year
Cash and Cash Equivalents
Summary Of Significant Accounting Policies [Line Items]
Maturity of time deposits		3 months

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Comparison on Effects of Adopting Topic 842 (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items]
Solar energy systems, net	$ 1,759,861	$ 1,938,874
Other non-current assets, net	680,062	28,090
Total cost of revenue	258,546	248,295
Gross profit	82,495	42,026
Sales and marketing	151,194	58,950
Total operating expenses	271,059	154,520
Customer Agreements and Incentives
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue	186,325	164,920
Solar Energy System and Product Sales
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue	$ 72,221	83,375
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Solar energy systems, net		1,550,787
Other non-current assets, net		416,177
Total cost of revenue		211,071
Gross profit		79,250
Sales and marketing		96,174
Total operating expenses		191,744
ASU 2016-02 | Customer Agreements and Incentives
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue		146,756
ASU 2016-02 | Solar Energy System and Product Sales
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue		64,315
Adjustments | ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Solar energy systems, net		(388,087)
Other non-current assets, net		388,087
Total cost of revenue		(37,224)
Gross profit		37,224
Sales and marketing		37,224
Total operating expenses		37,224
Adjustments | ASU 2016-02 | Customer Agreements and Incentives
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue		(18,164)
Adjustments | ASU 2016-02 | Solar Energy System and Product Sales
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue		$ (19,060)

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Additional Information (Details 1)	Dec. 31, 2019
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2020-01-01
Summary Of Significant Accounting Policies [Line Items]
Customer contract term	20 years

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Details) - Interest Rate Swaps - Fair Value Measurements, Recurring Basis - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial Assets	$ 3,245	$ 130
Financial Liabilities	28,070	11,146
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial Assets	3,245	130
Financial Liabilities	$ 28,070	$ 11,146

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Carrying Values and Fair Values of Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, Carrying Value	$ 1,524,815	$ 1,240,389
Unamortized debt issuance costs	(25,154)	(24,952)
Total long-term debt	1,499,661	1,215,437
Long-term debt, Fair Value	1,597,802	1,261,275
Floating-rate Long-term Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, Carrying Value	894,907	587,358
Long-term debt, Fair Value	894,907	587,358
Fixed-rate Long-term Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, Carrying Value	629,908	653,031
Long-term debt, Fair Value	$ 702,895	$ 673,917

Inventories - Summary of Invent

Inventories - Summary of Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Solar energy systems held for sale	$ 19,892	$ 12,321
Photovoltaic installation products	684	936
Total inventories	$ 20,576	$ 13,257

Solar Energy Systems (Details)

Solar Energy Systems (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Capitalized Costs of Equipment Installed Under Customer Agreements [Line Items]
Solar energy systems, gross	$ 1,926,809	$ 2,102,524
Less: Accumulated depreciation and amortization	(205,338)	(195,890)
Solar energy systems, net excluding inventory	1,721,471	1,906,634
Solar energy system inventory	38,390	32,240
Solar energy systems, net	1,759,861	1,938,874
System Equipment Costs
Capitalized Costs of Equipment Installed Under Customer Agreements [Line Items]
Solar energy systems, gross	$ 1,926,809	1,667,440
Initial Direct Costs Related to Solar Energy Systems
Capitalized Costs of Equipment Installed Under Customer Agreements [Line Items]
Solar energy systems, gross		$ 435,084

Solar Energy Systems - Addition

Solar Energy Systems - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Capitalized Costs of Equipment Installed Under Customer Agreements [Line Items]
Depreciation and amortization	$ 81,930,000	$ 69,634,000
Solar Energy System Inventory
Capitalized Costs of Equipment Installed Under Customer Agreements [Line Items]
Depreciation	0
Solar Energy Systems
Capitalized Costs of Equipment Installed Under Customer Agreements [Line Items]
Depreciation	$ 56,400,000
Depreciation and amortization		$ 66,300,000

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Lives	30 years
Property, gross	$ 25,759	$ 21,283
Less: Accumulated depreciation and amortization	(8,259)	(10,553)
Property and equipment, net	17,500	10,730
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, gross	10,458	10,560
Vehicles Acquired Under Finance Leases
Property Plant And Equipment [Line Items]
Property, gross	$ 10,280	6,907
Furniture and Computer and Other Equipment
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Lives	3 years
Property, gross	$ 5,021	$ 3,816
Minimum | Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Lives	1 year
Minimum | Vehicles Acquired Under Finance Leases
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Lives	3 years
Minimum | Furniture and Computer and Other Equipment
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Lives	3 years
Maximum | Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Lives	12 years
Maximum | Vehicles Acquired Under Finance Leases
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Lives	4 years
Maximum | Furniture and Computer and Other Equipment
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Lives	5 years

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Depreciation and amortization expense	$ 81,930	$ 69,634
Property and equipment
Property Plant And Equipment [Line Items]
Depreciation and amortization expense	$ 2,800	$ 4,800

Other Non-Current Assets - Sche

Other Non-Current Assets - Schedule of Other Non-Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Assets Noncurrent [Abstract]
Costs to obtain contracts	$ 615,385
Accumulated amortization of costs to obtain contracts	(70,170)
Prepaid inventory	50,104
Operating lease right-of-use assets	39,118
Sales incentives	10,008	$ 8,588
Debt issuance costs	9,936	2,415
Prepaid insurance	6,541	6,890
Advances receivable from sales professionals	6,395	5,109
Solar Lease straight-line asset	5,722	3,402
Other non-current assets	7,023	1,686
Total other non-current assets	$ 680,062	$ 28,090

Other Non-Current Assets - Addi

Other Non-Current Assets - Additional Information (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)
Other Assets Noncurrent [Abstract]
Amortization of costs to obtain contracts	$ 23.2
Cost to obtain contracts amortized term	20 years

Intangible Assets - Summary of

Intangible Assets - Summary of Net Intangible Assets Included in Other Non Current Assets, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Intangible assets, carrying value	$ 3,319	$ 1,743
Intangible assets, accumulated amortization	(617)	(1,204)
Total intangible assets, net	2,702	539
Internal-use software
Finite Lived Intangible Assets [Line Items]
Intangible assets, carrying value	2,596	1,020
Intangible assets, accumulated amortization	(105)	(781)
Developed Technology
Finite Lived Intangible Assets [Line Items]
Intangible assets, carrying value	522	522
Intangible assets, accumulated amortization	(393)	(324)
Trademarks/Trade Names
Finite Lived Intangible Assets [Line Items]
Intangible assets, carrying value	201	201
Intangible assets, accumulated amortization	$ (119)	$ (99)

Intangible Assets - Additional

Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 0.2	$ 0.5
Capitalized implementation costs	$ 2.4
Amortization period of intangible assets	5 years

Intangible Assets - Summary o_2

Intangible Assets - Summary of Expected Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
2020	$ 635
2021	605
2022	495
2023	492
2024	475
Total intangible assets, net	$ 2,702	$ 539

Accrued Compensation - Summary

Accrued Compensation - Summary of Accrued Compensation (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued Compensation Disclosure [Abstract]
Accrued payroll	$ 18,633	$ 16,352
Accrued commissions	15,516	9,168
Total accrued compensation	$ 34,149	$ 25,520

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities - Schedule of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued unused commitment fees and interest	$ 16,995	$ 14,102
Litigation settlement	12,780	100
Current portion of operating lease liabilities	8,436
Accrued workers' compensation	7,166	4,033
Accrued professional fees	5,546	6,150
Current portion of lease pass-through financing obligation	5,147	5,038
Accrued inventory	4,667	4,380
Sales, use and property taxes payable	4,321	3,132
Workmanship accrual	4,217	2,630
External customer experience services	1,984
Other accrued expenses	7,280	3,295
Total accrued and other current liabilities	$ 78,539	$ 42,860

Debt Obligations - Schedule of

Debt Obligations - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands		1 Months Ended		12 Months Ended
		Aug. 31, 2018	Jun. 30, 2018	Dec. 31, 2019		Dec. 31, 2018
Debt Instrument [Line Items]
Principal Borrowings Outstanding				$ 1,524,815		$ 1,240,389
Unamortized Debt Issuance Costs, Current				(339)		(295)
Unamortized Debt Issuance Costs, Long-term				(24,815)		(24,657)
Current portion of long-term debt				16,405		12,155
Long-term debt, net of current portion				1,483,256		1,203,282
Unused Borrowing Capacity				223,549		396,575
Solar Asset Backed Notes, Series 2018-1
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[1]			448,277		462,826
Unamortized Debt Issuance Costs, Current	[1]			(69)		(74)
Unamortized Debt Issuance Costs, Long-term	[1]			(8,414)		(9,172)
Current portion of long-term debt	[1]			3,639		3,655
Long-term debt, net of current portion	[1]			$ 436,155		$ 449,925
Interest Rate	[1]			5.10%		5.10%
Maturity Date	[1]			Oct. 31, 2028		Oct. 31, 2028
2017 Term Loan Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding				$ 180,365		$ 188,922
Unamortized Debt Issuance Costs, Current				(164)		(170)
Unamortized Debt Issuance Costs, Long-term				(4,235)		(4,614)
Current portion of long-term debt				7,882		6,679
Long-term debt, net of current portion				$ 168,084		$ 177,459
Interest Rate				6.00%		6.00%
Maturity Date				Jan. 31, 2035		Jan. 31, 2035
Solar Asset Backed Notes, Series 2018-2
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[2],[3]			$ 338,294		$ 342,833
Unamortized Debt Issuance Costs, Current	[2],[3]			(5)		(6)
Unamortized Debt Issuance Costs, Long-term	[2],[3]			(6,133)		(7,388)
Current portion of long-term debt	[2],[3]			1,245		294
Long-term debt, net of current portion	[2],[3]			$ 330,911		$ 335,145
Interest Rate	[2],[3]			5.50%		5.40%
Maturity Date			Aug. 29, 2023	Aug. 31, 2023	[2],[3]	Aug. 31, 2023	[2],[3]
2018 Forward Flow Loan Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding				$ 124,800		$ 58,425
Unamortized Debt Issuance Costs, Current				(99)		(43)
Unamortized Debt Issuance Costs, Long-term				(3,083)		(3,365)
Current portion of long-term debt				3,622		1,512
Long-term debt, net of current portion				$ 117,996		53,505
Unused Borrowing Capacity						$ 71,575
Interest Rate				4.70%		5.20%
Maturity Date		Nov. 20, 2039		Nov. 30, 2039		Nov. 30, 2039
2019 Forward Flow Loan Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[4]			$ 82,813
Unamortized Debt Issuance Costs, Long-term	[4]			(2,857)
Long-term debt, net of current portion	[4]			79,956
Unused Borrowing Capacity	[4]			$ 67,187
Interest Rate	[4]			4.70%
Credit Agreement
Debt Instrument [Line Items]
Principal Borrowings Outstanding				$ 1,266		$ 1,283
Unamortized Debt Issuance Costs, Current				(2)		(2)
Unamortized Debt Issuance Costs, Long-term				(93)		(118)
Current portion of long-term debt				17		15
Long-term debt, net of current portion				$ 1,154		$ 1,148
Interest Rate				6.50%		6.50%
Maturity Date				Feb. 28, 2023		Feb. 28, 2023
Revolving Warehouse Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[5]			$ 250,000
Long-term debt, net of current portion	[5]			250,000
Unused Borrowing Capacity	[5]			$ 75,000
Interest Rate	[5]			4.30%
Maturity Date	[5]			Aug. 31, 2023
Asset Financing Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[5],[6]			$ 99,000
Long-term debt, net of current portion	[5],[6]			99,000
Unused Borrowing Capacity	[5],[6]			$ 81,362
Interest Rate	[5],[6]			5.20%
Maturity Date	[5],[6]			Jun. 30, 2023
Aggregation Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[5]					$ 50,000
Long-term debt, net of current portion	[5]					50,000
Unused Borrowing Capacity	[5]					$ 325,000
Interest Rate	[5]					5.70%
Maturity Date	[5]					Sep. 30, 2020
Working Capital Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[5],[6]					$ 136,100
Long-term debt, net of current portion	[5],[6]					$ 136,100
Interest Rate	[5],[6]					5.60%
Maturity Date	[5],[6]					Mar. 31, 2020
[1]	The interest rate disclosed in the table above is a weighted-average rate. The Series 2018-1 Notes are composed of Class A and Class B Notes. Class A Notes accrue interest at 4.73%. Class B Notes accrue interest at 7.37%.
[2]	The Series 2018-2 Notes are composed of Class A and Class B Notes. Class B Notes accrue interest at a rate of LIBOR plus 4.75%. Class A Notes accrue interest at a variable spread over LIBOR that results in a weighted average spread for all 2018-2 Notes of 2.95%.
[3]	The interest rate of this facility is partially hedged to an effective interest rate of 6.0% for $323.6 million of the principal borrowings. See Note 13—Derivative Financial Instruments.
[4]	The maturity date for this facility is 20 years from the end date of the borrowing availability period when all borrowings are aggregated into one term loan, which will be no later than November 20, 2020.
[5]	Revolving lines of credit are not presented net of unamortized debt issuance costs.
[6]	Facility is recourse debt, which refers to debt that is collateralized by the Company’s general assets. All of the Company’s other debt obligations are non-recourse, which refers to debt that is only collateralized by specified assets or subsidiaries of the Company.

Debt Obligations - Schedule o_2

Debt Obligations - Schedule of Debt Obligations (Parenthetical) (Details) - USD ($)		1 Months Ended		12 Months Ended
		May 31, 2019	Jun. 30, 2018	Dec. 31, 2019		Dec. 31, 2018
Debt Instrument [Line Items]
Principal borrowings outstanding				$ 1,524,815,000		$ 1,240,389,000
Solar Asset Backed Notes, Series 2018-1
Debt Instrument [Line Items]
Interest Rate	[1]			5.10%		5.10%
Principal borrowings outstanding	[1]			$ 448,277,000		$ 462,826,000
Maturity Date	[1]			Oct. 31, 2028		Oct. 31, 2028
Solar Asset Backed Notes, Series 2018-1 | Class A Notes
Debt Instrument [Line Items]
Interest Rate			4.73%	4.73%
Principal borrowings outstanding			$ 400,000,000
Maturity Date			Oct. 30, 2028
Solar Asset Backed Notes, Series 2018-1 | Class B Notes
Debt Instrument [Line Items]
Interest Rate			7.37%	7.37%
Principal borrowings outstanding			$ 66,000,000
Maturity Date			Oct. 30, 2028
Solar Asset Backed Notes, Series 2018-2
Debt Instrument [Line Items]
Interest Rate	[2],[3]			5.50%		5.40%
Principal borrowings outstanding	[2],[3]			$ 338,294,000		$ 342,833,000
Maturity Date			Aug. 29, 2023	Aug. 31, 2023	[2],[3]	Aug. 31, 2023	[2],[3]
Solar Asset Backed Notes, Series 2018-2 | Interest Rate Swaps
Debt Instrument [Line Items]
Effective interest rate of principal borrowings			5.95%	6.00%
Principal borrowings outstanding				$ 323,600,000
Solar Asset Backed Notes, Series 2018-2 | L I B O R Plus | Weighted Average
Debt Instrument [Line Items]
Debt instrument interest rate			2.95%
Solar Asset Backed Notes, Series 2018-2 | Class A Notes
Debt Instrument [Line Items]
Principal borrowings outstanding			$ 296,000,000
Solar Asset Backed Notes, Series 2018-2 | Class A Notes | L I B O R Plus | Weighted Average
Debt Instrument [Line Items]
Debt instrument interest rate			2.95%	2.95%
Solar Asset Backed Notes, Series 2018-2 | Class B Notes
Debt Instrument [Line Items]
Principal borrowings outstanding			$ 49,000,000
Solar Asset Backed Notes, Series 2018-2 | Class B Notes | L I B O R Plus
Debt Instrument [Line Items]
Debt instrument interest rate				4.75%
Solar Asset Backed Notes, Series 2018-2 | Class B Notes | L I B O R Plus | Weighted Average
Debt Instrument [Line Items]
Debt instrument interest rate			4.75%
2019 Forward Flow Loan Facility
Debt Instrument [Line Items]
Interest Rate	[4]			4.70%
Principal borrowings outstanding	[4]			$ 82,813,000
Debt instrument maturity period		20 years		20 years
2019 Forward Flow Loan Facility | Maximum
Debt Instrument [Line Items]
Maturity Date				Nov. 20, 2020
[1]	The interest rate disclosed in the table above is a weighted-average rate. The Series 2018-1 Notes are composed of Class A and Class B Notes. Class A Notes accrue interest at 4.73%. Class B Notes accrue interest at 7.37%.
[2]	The Series 2018-2 Notes are composed of Class A and Class B Notes. Class B Notes accrue interest at a rate of LIBOR plus 4.75%. Class A Notes accrue interest at a variable spread over LIBOR that results in a weighted average spread for all 2018-2 Notes of 2.95%.
[3]	The interest rate of this facility is partially hedged to an effective interest rate of 6.0% for $323.6 million of the principal borrowings. See Note 13—Derivative Financial Instruments.
[4]	The maturity date for this facility is 20 years from the end date of the borrowing availability period when all borrowings are aggregated into one term loan, which will be no later than November 20, 2020.

Debt Obligations - Additional I

Debt Obligations - Additional Information (Details) - USD ($)		1 Months Ended				12 Months Ended
		Aug. 31, 2019	May 31, 2019	Aug. 31, 2018	Jun. 30, 2018	Dec. 31, 2019		Dec. 31, 2018		Jan. 31, 2017	Feb. 29, 2016
Debt Instrument [Line Items]
Principal Borrowings Outstanding						$ 1,524,815,000		$ 1,240,389,000
Restricted cash and cash equivalents						89,892,000		71,305,000
Unamortized debt issuance costs						25,154,000		24,952,000
Letter of credit related to insurance contracts						19,600,000
Minimum
Debt Instrument [Line Items]
Restricted cash and cash equivalents						10,000,000		10,000,000
Required Reserves
Debt Instrument [Line Items]
Restricted cash and cash equivalents						79,900,000
Solar Asset Backed Notes, Series 2018-1
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[1]					$ 448,277,000		$ 462,826,000
Interest Rate	[1]					5.10%		5.10%
Revolving credit facility maturity date	[1]					Oct. 31, 2028		Oct. 31, 2028
Solar Asset Backed Notes, Series 2018-1 | Required Reserves
Debt Instrument [Line Items]
Restricted cash and cash equivalents						$ 16,300,000
Solar Asset Backed Notes, Series 2018-1 | Class A Notes
Debt Instrument [Line Items]
Principal Borrowings Outstanding					$ 400,000,000
Interest Rate					4.73%	4.73%
Revolving credit facility maturity date					Oct. 30, 2028
Solar Asset Backed Notes, Series 2018-1 | Class B Notes
Debt Instrument [Line Items]
Principal Borrowings Outstanding					$ 66,000,000
Interest Rate					7.37%	7.37%
Revolving credit facility maturity date					Oct. 30, 2028
Solar Asset Backed Notes, Series 2018-2
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[2],[3]					$ 338,294,000		$ 342,833,000
Interest Rate	[2],[3]					5.50%		5.40%
Revolving credit facility maturity date					Aug. 29, 2023	Aug. 31, 2023	[2],[3]	Aug. 31, 2023	[2],[3]
Solar Asset Backed Notes, Series 2018-2 | Interest Rate Swaps
Debt Instrument [Line Items]
Principal Borrowings Outstanding						$ 323,600,000
Effective interest rate of principal borrowings					5.95%	6.00%
Solar Asset Backed Notes, Series 2018-2 | L I B O R Plus | Weighted Average
Debt Instrument [Line Items]
Debt instrument interest rate					2.95%
Solar Asset Backed Notes, Series 2018-2 | Required Reserves
Debt Instrument [Line Items]
Restricted cash and cash equivalents						$ 25,400,000
Solar Asset Backed Notes, Series 2018-2 | Class A Notes
Debt Instrument [Line Items]
Principal Borrowings Outstanding					$ 296,000,000
Solar Asset Backed Notes, Series 2018-2 | Class A Notes | L I B O R Plus | Weighted Average
Debt Instrument [Line Items]
Debt instrument interest rate					2.95%	2.95%
Solar Asset Backed Notes, Series 2018-2 | Class B Notes
Debt Instrument [Line Items]
Principal Borrowings Outstanding					$ 49,000,000
Solar Asset Backed Notes, Series 2018-2 | Class B Notes | L I B O R Plus
Debt Instrument [Line Items]
Debt instrument interest rate						4.75%
Solar Asset Backed Notes, Series 2018-2 | Class B Notes | L I B O R Plus | Weighted Average
Debt Instrument [Line Items]
Debt instrument interest rate					4.75%
2016 Term Loan Facility
Debt Instrument [Line Items]
Payment of outstanding balance of debt					$ 282,300,000
Payment of outstanding balance of debt principal					281,800,000
Payment of outstanding balance of debt accrued interest					500,000
Unamortized debt issuance costs recognized in interest expense								$ 6,900,000
Prepayment fee					0
Subordinated HoldCo Facility
Debt Instrument [Line Items]
Payment of outstanding balance of debt					206,400,000
Payment of outstanding balance of debt principal					196,600,000
Payment of outstanding balance of debt accrued interest					3,900,000
Unamortized debt issuance costs recognized in interest expense								2,900,000
Prepayment fee					$ 5,900,000
Percentage of principal prepayments fee					3.00%
Interest on borrowings accrue at an annual fixed rate and payable in arrears											6.50%
Subordinated HoldCo Facility | Interest Expense
Debt Instrument [Line Items]
Prepayment fee								5,900,000
2017 Term Loan Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding						$ 180,365,000		$ 188,922,000
Interest Rate						6.00%		6.00%
Revolving credit facility maturity date						Jan. 31, 2035		Jan. 31, 2035
Interest on borrowings accrue at an annual fixed rate and payable in arrears										6.00%
Debt instrument, frequency of periodic payment						quarterly basis
2017 Term Loan Facility | Required Reserves
Debt Instrument [Line Items]
Restricted cash and cash equivalents						$ 20,400,000
Aggregation Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[4]							$ 50,000,000
Interest Rate	[4]							5.70%
Revolving credit facility maturity date	[4]							Sep. 30, 2020
Payment of outstanding balance of debt		$ 121,400,000
Payment of outstanding balance of debt principal		115,000,000
Payment of outstanding balance of debt accrued interest		600,000
Unamortized debt issuance costs recognized in interest expense						2,500,000
Amounts related to settle interest rate swaps		5,800,000
Unamortized debt issuance costs		3,600,000
Deferred unamortized debt issuance costs		1,100,000
Working Capital Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[4],[5]							$ 136,100,000
Interest Rate	[4],[5]							5.60%
Revolving credit facility maturity date	[4],[5]							Mar. 31, 2020
Payment of outstanding balance of debt						130,800,000
Payment of outstanding balance of debt principal						130,300,000
Payment of outstanding balance of debt accrued interest						500,000
Unamortized debt issuance costs recognized in interest expense						200,000
Unamortized debt issuance costs						200,000
2018 Forward Flow Loan Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding						$ 124,800,000		$ 58,425,000
Interest Rate						4.70%		5.20%
Revolving credit facility maturity date				Nov. 20, 2039		Nov. 30, 2039		Nov. 30, 2039
Interest on borrowings accrue at an annual fixed rate and payable in arrears				4.70%
Maximum borrowing amount under credit agreement				$ 124,800,000
2018 Forward Flow Loan Facility | Required Reserves
Debt Instrument [Line Items]
Restricted cash and cash equivalents						$ 6,400,000
2019 Forward Flow Loan Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[6]					$ 82,813,000
Interest Rate	[6]					4.70%
Maximum borrowing amount under credit agreement			$ 150,000,000
Debt instrument maturity period			20 years			20 years
Debt instrument offering date			Nov. 20, 2020
Debt Instrument interest rate description						Interest on each loan will accrue at an annual rate equal to the greater of (a) 4.70% and (b) the U.S. Treasury rate for the weighted-average life of such loan, plus an applicable margin equal to 2.35%. Scheduled principal payments are due on a quarterly basis, at the end of January, April, July and October of each year.
Prepayment percentage on outstanding loans			102.50%
2019 Forward Flow Loan Facility | Maximum
Debt Instrument [Line Items]
Revolving credit facility maturity date						Nov. 20, 2020
2019 Forward Flow Loan Facility | Market Index-Based Risk Premium
Debt Instrument [Line Items]
Debt instrument interest rate			4.70%
2019 Forward Flow Loan Facility | U.S. Treasury Rate
Debt Instrument [Line Items]
Debt instrument interest rate			2.35%
2019 Forward Flow Loan Facility | Required Reserves
Debt Instrument [Line Items]
Restricted cash and cash equivalents						$ 2,500,000
Revolving Warehouse Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[4]					$ 250,000,000
Interest Rate	[4]					4.30%
Revolving credit facility maturity date	[4]					Aug. 31, 2023
Maximum borrowing amount under credit agreement		325,000,000
Line of credit facility option to expand maximum borrowing capacity		$ 400,000,000
Revolving Warehouse Facility | Interest Rate Swaps | Minimum
Debt Instrument [Line Items]
Percentage of outstanding term loans in interest rate hedged		90.00%				90.00%
Revolving Warehouse Facility | L I B O R Plus
Debt Instrument [Line Items]
Debt instrument interest rate		2.375%
Revolving Warehouse Facility | Required Reserves
Debt Instrument [Line Items]
Restricted cash and cash equivalents						$ 6,200,000
Revolving Warehouse Facility | After Three Years Term of Facility | L I B O R Plus
Debt Instrument [Line Items]
Debt instrument interest rate		3.375%
Asset Financing Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[4],[5]					$ 99,000,000
Interest Rate	[4],[5]					5.20%
Revolving credit facility maturity date	[4],[5]					Jun. 30, 2023
Restricted cash and cash equivalents						$ 2,600
Maximum borrowing amount under credit agreement						200,000
Letter of credit related to insurance contracts						19,600
Minimum cash balance requirement						$ 30,000,000
Asset Financing Facility | Base Rate Loans
Debt Instrument [Line Items]
Interest Rate						2.25%
Asset Financing Facility | LIBOR Loans
Debt Instrument [Line Items]
Interest Rate						3.25%
Asset Financing Facility | L I B O R Plus | Base Rate Loans
Debt Instrument [Line Items]
Debt instrument interest rate						1.00%
Asset Financing Facility | Federal Funds Rate Plus | Base Rate Loans
Debt Instrument [Line Items]
Debt instrument interest rate						0.50%
Asset Financing Facility | Floor Rate | Base Rate Loans
Debt Instrument [Line Items]
Debt instrument interest rate						0.00%
Asset Financing Facility | Floor Rate | LIBOR Loans
Debt Instrument [Line Items]
Debt instrument interest rate						0.00%
[1]	The interest rate disclosed in the table above is a weighted-average rate. The Series 2018-1 Notes are composed of Class A and Class B Notes. Class A Notes accrue interest at 4.73%. Class B Notes accrue interest at 7.37%.
[2]	The Series 2018-2 Notes are composed of Class A and Class B Notes. Class B Notes accrue interest at a rate of LIBOR plus 4.75%. Class A Notes accrue interest at a variable spread over LIBOR that results in a weighted average spread for all 2018-2 Notes of 2.95%.
[3]	The interest rate of this facility is partially hedged to an effective interest rate of 6.0% for $323.6 million of the principal borrowings. See Note 13—Derivative Financial Instruments.
[4]	Revolving lines of credit are not presented net of unamortized debt issuance costs.
[5]	Facility is recourse debt, which refers to debt that is collateralized by the Company’s general assets. All of the Company’s other debt obligations are non-recourse, which refers to debt that is only collateralized by specified assets or subsidiaries of the Company.
[6]	The maturity date for this facility is 20 years from the end date of the borrowing availability period when all borrowings are aggregated into one term loan, which will be no later than November 20, 2020.

Debt Obligations - Scheduled Ma

Debt Obligations - Scheduled Maturities of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
2020	$ 14,425
2021	15,803
2022	21,065
2023	704,801
2024	28,908
Thereafter	739,813
Total	$ 1,524,815	$ 1,240,389

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs and Other Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Lease cost
Amortization of right-of-use assets	$ 1,758
Interest on lease liabilities	326
Operating lease cost	11,329
Short-term lease cost	2,069
Total lease cost	15,482
Finance leases:
Operating cash outflows from finance leases	326
Financing cash outflows from finance leases	1,480	$ 3,323
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 9,482	$ 1,622
Weighted-average remaining lease term - finance leases (in years)	3 years 7 months 6 days
Weighted-average discount rate - finance leases	7.20%
Operating leases:
Operating cash outflows from operating leases	$ 11,460
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 12,217
Weighted-average remaining lease term - operating leases (in years)	8 years 10 months 24 days
Weighted-average discount rate - operating leases	8.00%

Leases - Additional Information

Leases - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019USD ($)ft²Option
Lessee Lease Description [Line Items]
Operating leases right-of-use assets	$ 39,118,000
Operating leases lease liabilities	$ 48,157,000
Fleet Vehicles Lease
Lessee Lease Description [Line Items]
Lessee, Finance Lease, Existence of Option to Extend [true false]	true
Description of finance lease, option to extend	The master lease agreements allow for the Company to extend fleet vehicle leases on a month-to-month basis
Fleet Vehicles Lease | Minimum
Lessee Lease Description [Line Items]
Finance lease, agreement period	3 years
Fleet Vehicles Lease | Maximum
Lessee Lease Description [Line Items]
Finance lease, agreement period	4 years
Office Lease
Lessee Lease Description [Line Items]
Operating lease, additional term	3 years
Operating lease, term of contract	15 years
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Description of operating lease, option to extend	The corporate office lease includes options to extend the lease term for two additional periods of five years
Office Lease | Newly Constructed Building
Lessee Lease Description [Line Items]
Operating lease, term of contract	11 years 6 months
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Description of operating lease, option to extend	The lease commenced subsequent to December 31, 2019 and as such, there was no right-of-use asset or lease liability related to this lease recorded for year ended December 31, 2019. The initial term of the lease is approximately 11.5 years, with two options to extend the lease for five years
Increase of lease office premises | ft²	32,000
Anticipated lease commencement date	Jan. 1, 2020
Operating leases right-of-use assets	$ 0
Operating leases lease liabilities	$ 0
Number of options to extend the lease | Option	2
Operating lease, renewal term	5 years
Additional expected rent payments	$ 11,200,000
Office Lease | Existing Office Building
Lessee Lease Description [Line Items]
Operating lease, term of contract	5 years 6 months
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Description of operating lease, option to extend	The lease is expected to commence in the first quarter of 2020 and as such, there was no right-of-use asset or lease liability related to this lease recorded for the year ended December 31, 2019. The initial term of the lease is approximately 5.5 years, with two options to extend the lease for two years
Increase of lease office premises | ft²	40,000
Anticipated lease commencement date	Mar. 31, 2020
Operating leases right-of-use assets	$ 0
Operating leases lease liabilities	$ 0
Number of options to extend the lease | Option	2
Operating lease, renewal term	2 years
Additional expected rent payments	$ 4,600,000
Warehouse Lease Agreement
Lessee Lease Description [Line Items]
Operating lease, term of contract	5 years
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Warehouse Lease Agreement | Minimum
Lessee Lease Description [Line Items]
Operating lease, term of contract	1 year
Warehouse Lease Agreement | Maximum
Lessee Lease Description [Line Items]
Operating lease, term of contract	9 years
Equipment Lease Agreement | Minimum
Lessee Lease Description [Line Items]
Operating lease, term of contract	3 years
Equipment Lease Agreement | Maximum
Lessee Lease Description [Line Items]
Operating lease, term of contract	5 years

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Lease Payments for Finance Leases (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Finance Lease Liabilities Payments Due [Abstract]
2020	$ 2,806
2021	2,775
2022	2,649
2023	1,607
Total minimum lease payments	9,837
Less: interest	1,120
Present value of finance lease obligations	8,717
Less: current portion	2,274	$ 1,921
Long-term portion	$ 6,443	$ 505

Leases - Schedule of Future M_2

Leases - Schedule of Future Minimum Lease Payments Under Non-cancellable Operating Leases (Details) $ in Thousands	Dec. 31, 2019USD ($)
Operating Lease Liabilities Payments Due [Abstract]
2020	$ 11,883
2021	8,779
2022	6,481
2023	5,038
2024	4,803
Thereafter	31,877
Total minimum lease payments	68,861
Less: present value impact	20,704
Present value of operating lease obligations	48,157
Less: current portion	8,436
Long-term portion	$ 39,721

Derivative Financial Instrume_3

Derivative Financial Instruments - Schedule of Derivative Financial Instruments at Fair Value (Details) - Interest Rate Swaps - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Noncurrent Liabilities
Derivatives Fair Value [Line Items]
Fair Value, Derivatives designated as hedging instruments	$ 28,070	$ 9,884
Fair Value, Derivatives not designated as hedging instruments		1,262
Other Noncurrent Assets
Derivatives Fair Value [Line Items]
Fair Value, Derivatives not designated as hedging instruments	$ 3,245	$ 130

Derivative Financial Instrume_4

Derivative Financial Instruments - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Aug. 31, 2019
Derivatives Fair Value [Line Items]
Realized gain on interest rate swaps	$ 4,377,000	$ 148,000
Interest Expense
Derivatives Fair Value [Line Items]
Realized gain on interest rate swaps	$ (1,467,000)	21,601,000
2016 Term Loan Facility | Derivatives Designated as Hedging Instruments | Interest Expense
Derivatives Fair Value [Line Items]
Realized gain on interest rate swaps		$ 22,500,000
Revolving Warehouse Facility | Interest Rate Swaps | Minimum
Derivatives Fair Value [Line Items]
Percentage of outstanding term loans in interest rate hedged	90.00%		90.00%
Revolving Warehouse Facility | Derivatives Not Designated as Hedging Instruments
Derivatives Fair Value [Line Items]
Notional amount	$ 153,000,000
Revolving Warehouse Facility | Derivatives Not Designated as Hedging Instruments | Additional Interest Rate Swaps
Derivatives Fair Value [Line Items]
Notional amount	72,000,000
2018-2 Notes | Interest Rate Swaps
Derivatives Fair Value [Line Items]
Notional amount	323,600,000
Accumulated other comprehensive income, expected amount of cash flow hedge to be reclassified to interest expense within the next 12 months	$ 4,600,000

Derivative Financial Instrume_5

Derivative Financial Instruments - Schedule of Losses (Gains) on Derivative Financial Instruments Recognized in OCI and Condensed Consolidated Statements of Operations Before Tax Effect (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts presented in the income statement line items, Interest expense	$ 82,323	$ 65,308
Total losses (gains)	(4,377)	(148)
Total amounts presented in the income statement line items, Other (income) expense, net	1,434	(4,538)
Interest Expense, Net
Derivative Instruments, Gain (Loss) [Line Items]
Total losses (gains)	1,467	(21,601)
Other Expense (Income), Net
Derivative Instruments, Gain (Loss) [Line Items]
Total losses (gains)	1,433	(2,420)
Derivatives Designated as Hedging Instruments | Cash Flow Hedging | Interest Rate Swaps | Interest Expense, Net
Derivative Instruments, Gain (Loss) [Line Items]
Losses (gains) reclassified from AOCI into income	1,467	(21,601)
Derivatives Designated as Hedging Instruments | Cash Flow Hedging | Interest Rate Swaps | Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Losses recognized in OCI	19,653	2,311
Derivatives Not Designated as Hedging Instruments | Interest Rate Swaps | Other Expense (Income), Net
Derivative Instruments, Gain (Loss) [Line Items]
Losses (gains) recognized in income	$ 1,433	$ (2,420)

Investment Funds - Additional I

Investment Funds - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Investment Holdings [Line Items]
Summary of investment fund	The Company has formed investment funds for the purpose of funding the purchase of solar energy systems under long-term customer contracts.
Investors cash contribution to variable interest equity	$ 1,949,700,000	$ 1,565,300,000
Solar energy systems, net	1,759,861,000	1,938,874,000
Prepaid insurance balance	8,100,000	8,300,000
Distributions paid to reimburse fund investors	2,600,000	11,900,000
Accrued estimated distribution	1,100,000
Restricted cash	89,892,000	71,305,000
Minimum
Investment Holdings [Line Items]
Restricted cash	10,000,000	10,000,000
Variable Interest Entities
Investment Holdings [Line Items]
Investment tax credit repayment	0
Financing Obligation
Investment Holdings [Line Items]
Solar energy systems, net	43,800,000	55,800,000
Financing liabilities	4,600,000	$ 5,300,000
Investor
Investment Holdings [Line Items]
Investors cash contribution to variable interest equity	$ 110,000,000

Investment Funds - Aggregate Ca

Investment Funds - Aggregate Carrying Value of Funds Assets and Liabilities (Details) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents		$ 166,048	$ 219,591
Accounts receivable, net		24,314	14,207
Prepaid expenses and other current assets		41,137	31,201
Total current assets		252,075	278,256
Restricted cash and cash equivalents		89,892	71,305
Other non-current assets, net		680,062	28,090
TOTAL ASSETS	[1]	2,799,390	2,327,255
Current liabilities:
Distributions payable to non-controlling interests and redeemable non-controlling interests		10,253	7,846
Current portion of long-term debt		16,405	12,155
Current portion of deferred revenue		40,715	30,199
Accrued and other current liabilities		78,539	42,860
Total current liabilities		241,342	166,430
Long-term debt, net of current portion		1,483,256	1,203,282
Deferred revenue, net of current portion		17,631	13,524
Other non-current liabilities		74,423	24,610
Total liabilities	[1]	2,406,790	1,845,471
Variable Interest Entities
Current assets:
Cash and cash equivalents		82,764	62,350
Accounts receivable, net		8,922	6,593
Prepaid expenses and other current assets		1,676	1,289
Total current assets		93,362	70,232
Restricted cash and cash equivalents		8,890	2,443
Solar energy systems, net		1,587,354	1,752,271
Other non-current assets, net		504,668	10,888
TOTAL ASSETS		2,194,274	1,835,834
Current liabilities:
Distributions payable to non-controlling interests and redeemable non-controlling interests		10,253	7,846
Current portion of long-term debt		3,622	1,512
Current portion of deferred revenue		2,590	2,320
Accrued and other current liabilities		6,394	4,860
Total current liabilities		22,859	16,538
Long-term debt, net of current portion		197,952	53,505
Deferred revenue, net of current portion		12,242	9,694
Other non-current liabilities		301	1,023
Total liabilities		$ 233,354	$ 80,760
[1]	The Company’s consolidated assets as of December 31, 2019 and 2018 include $2,194.3 million and $1,835.8 million consisting of assets of variable interest entities (“VIEs”) that can only be used to settle obligations of the VIEs. These assets include cash and cash equivalents of $82.8 million and $62.4 million as of December 31, 2019 and 2018; accounts receivable, net, of $8.9 million and $6.6 million as of December 31, 2019 and 2018; prepaid expenses and other current assets of $1.7 million and $1.3 million as of December 31, 2019 and 2018; restricted cash and cash equivalents of $8.9 million and $2.4 million as of December 31, 2019 and 2018; solar energy systems, net, of $1,587.4 million and $1,752.3 million as of December 31, 2019 and 2018; and other non-current assets, net of $504.7 million and $10.9 million as of December 31, 2019 and 2018. The Company’s consolidated liabilities as of December 31, 2019 and 2018 included $233.4 million and $80.8 million of liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include distributions payable to non-controlling interests and redeemable non-controlling interests of $10.3 million and $7.8 million as of December 31, 2019 and 2018; accrued and other current liabilities of $6.4 million and $4.9 million as of December 31, 2019 and 2018; long-term debt of $201.6 million and $55.0 million as of December 31, 2019 and 2018; deferred revenue of $14.8 million and $12.0 million as of December 31, 2019 and 2018; and other non-current liabilities of $0.3 million and $1.0 million as of December 31, 2019 and 2018. For further information see Note 14—Investment Funds.

Redeemable Non-Controlling In_3

Redeemable Non-Controlling Interests and Equity and Preferred Stock - Additional Information (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Redeemable Noncontrolling Interest [Line Items]
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	123,056,000	120,114,000
Common stock, shares outstanding	123,056,000	120,114,000
Preferred Stock, Shares Authorized	10,000,000
Preferred Stock, Shares Issued	0	0
Put Option | Minimum
Redeemable Noncontrolling Interest [Line Items]
Purchase price for investors' interest in funds under Put Options	$ 2.1
Put Option | Maximum
Redeemable Noncontrolling Interest [Line Items]
Purchase price for investors' interest in funds under Put Options	4.1
Call Option | Minimum
Redeemable Noncontrolling Interest [Line Items]
Purchase price for investors' interest in funds under Put Options	1.2
Call Option | Maximum
Redeemable Noncontrolling Interest [Line Items]
Purchase price for investors' interest in funds under Put Options	$ 7

Redeemable Non-Controlling In_4

Redeemable Non-Controlling Interests and Equity and Preferred Stock - Schedule of Shares of Common Stock Reserved for Issuance (Details) - shares	Dec. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Shares available for grant under equity incentive plans	13,060,000	13,323,000
Restricted stock units issued and outstanding	6,271,000	6,172,000
Stock options issued and outstanding	5,421,000	3,394,000
Long-term incentive plan	2,706,000	2,706,000
Total	27,458,000	25,595,000

Equity Compensation Plans - Add

Equity Compensation Plans - Additional Information (Details) - USD ($)	1 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2019	Dec. 31, 2018	Jul. 31, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under equity incentive plans		13,060,000	13,323,000
Long-term incentive plan		2,706,000	2,706,000
Number of shares granted and outstanding		5,421,000	3,394,000
Stock unit granted and outstanding		6,271,000	6,172,000
Expected dividend yield		$ 0
Income tax benefit related to share-based compensation		2,200,000	$ 1,400,000
RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Fair value of RSUs vested		$ 16,200,000	16,900,000
2014 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under equity incentive plans		13,100,000
Maximum annual increase in shares reserved for issuance		8,800,000
Percentage of outstanding shares of common stock		4.00%
Number of additional shares available for issuance		4,800,000
2014 Equity Incentive Plan | Time Based Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares granted and outstanding		5,400,000
2014 Equity Incentive Plan | RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock unit granted and outstanding		6,300,000
2014 Equity Incentive Plan | RSUs | Share-based Compensation Award, Tranche One
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock unit granted and outstanding		5,100,000
2014 Equity Incentive Plan | RSUs | Share-based Compensation Award, Tranche Two
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares expected to vest		1,200,000
2014 Equity Incentive Plan | Minimum | Time Based Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period		3 years
2014 Equity Incentive Plan | Minimum | RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period		1 year
2014 Equity Incentive Plan | Minimum | Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period		2 years
2014 Equity Incentive Plan | Maximum | Time Based Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period		4 years
2014 Equity Incentive Plan | Maximum | RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period		4 years
2014 Equity Incentive Plan | Maximum | Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Award vesting period		4 years
Two Thousand And Thirteen Omnibus Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares available for issuance	0
Stock options contractual period	10 years
Fair value of options vested		$ 2,000,000	1,700,000
Intrinsic value net of options exercised		$ 3,200,000	$ 4,400,000
Two Thousand And Thirteen Omnibus Incentive Plan | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted-average grant-date fair value of options granted		$ 3.52	$ 3.93
Long Term Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Long-term incentive plan				4,100,000
Long-term incentive plan, number of shares granted in period		1,100,000
Long-term incentive plan, number of shares remained outstanding		2,700,000
Long-term incentive plan, number of shares returned to 2014 Plan		300,000

Equity Compensation Plans - Sum

Equity Compensation Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares Underlying Options, Outstanding, Balance	3,394,000
Shares Underlying Options, Granted	2,674,000
Shares Underlying Options, Exercised	(578,000)
Shares Underlying Options, Cancelled	(69,000)
Shares Underlying Options, Outstanding, Balance	5,421,000
Shares Underlying Options, Options vested and exercisable	1,989,000
Weighted-Average Exercise Price, Outstanding, Balance	$ 2.77
Weighted-Average Exercise Price, Granted	5.60
Weighted-Average Exercise Price, Exercised	1.73
Weighted-Average Exercise Price, Cancelled	7.53
Weighted-Average Exercise Price, Outstanding, Balance	4.21
Weighted-Average Exercise Price, Options vested and exercisable	$ 2.65
Weighted-Average Remaining Contractual Term, Outstanding, Balance	7 years 9 months 18 days
Weighted-Average Remaining Contractual Term, Options vested and exercisable	5 years 8 months 12 days
Aggregate Intrinsic Value	$ 17,073	$ 4,689
Aggregate Intrinsic Value, Options vested and exercisable	$ 9,551

Equity Compensation Plans - Bla

Equity Compensation Plans - Black-Scholes-Merton Option Pricing Model Used to Estimate Fair Value (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected term (in years)	6 years 3 months 18 days	6 years 2 months 12 days
Volatility	67.80%	70.70%
Risk-free interest rate	2.30%	2.80%
Dividend yield	0.00%	0.00%

Equity Compensation Plans - RSU

Equity Compensation Plans - RSU Activity (Details)	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Awards, Outstanding at December 31, 2017 | shares	6,172,000
Number of Awards, Granted | shares	3,130,000
Number of Awards, Vested | shares	(2,364,000)
Number of Awards, Forfeited | shares	(667,000)
Number of Awards, Outstanding at December 31, 2018 | shares	6,271,000
Weighted Average Grant Date Fair Value, Outstanding at December 31, 2017 | $ / shares	$ 3.84
Weighted Average Grant Date Fair Value, Granted | $ / shares	6.01
Weighted Average Grant Date Fair Value, Vested | $ / shares	3.83
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	4.51
Weighted Average Grant Date Fair Value, Outstanding at December 31, 2018 | $ / shares	$ 4.85

Equity Compensation Plans - S_2

Equity Compensation Plans - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	$ 16,418	$ 13,163
Cost of Revenue
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	1,653	1,333
Sales and Marketing
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	3,305	3,353
General and Administrative
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	11,330	8,344
Research and Development
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	$ 130	$ 133

Equity Compensation Plans - S_3

Equity Compensation Plans - Summary of Unrecognized Stock-Based Compensation Expense (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Schedule Of Stock Options [Line Items]
Unrecognized Stock-Based Compensation Expense	$ 25,799
RSUs
Schedule Of Stock Options [Line Items]
Unrecognized Stock-Based Compensation Expense, other than stock options	$ 18,726
Weighted- Average Period of Recognition	1 year 8 months 12 days
Stock Options
Schedule Of Stock Options [Line Items]
Unrecognized Stock-Based Compensation Expense, stock options	$ 7,073
Weighted- Average Period of Recognition	2 years

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ (711)	$ (665)
State	162	102
Total current benefit	(549)	(563)
Deferred:
Federal	101,965	79,048
State	49,583	27,814
Total deferred expense	151,548	106,862
Income tax expense	$ 150,999	$ 106,299

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliation on Income Tax Benefit Computed at Statutory Federal Rate and Income Tax Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Expense Benefit Continuing Operations Income Tax Reconciliation [Abstract]
Income tax benefit—computed as 21% of pretax loss	$ (57,187)	$ (36,385)
Effect of non-controlling interests and redeemable non-controlling interests	67,440	55,434
State and local income tax expenses (net of federal benefit)	39,299	22,054
Tax gains on sale of solar energy systems to investment funds	103,689	68,683
Effect of tax credits	(2,781)	(2,684)
Other	539	(803)
Income tax expense	$ 150,999	$ 106,299

Income Taxes - Schedule of Re_2

Income Taxes - Schedule of Reconciliation on Income Tax Benefit Computed at Statutory Federal Rate and Income Tax Expense (Parenthetical) (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income tax benefit—statutory federal rate	21.00%	21.00%

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred tax assets:
Accruals and reserves	$ 13,719	$ 6,552
Stock-based compensation	5,698	4,204
Investment tax and other credits	51,721	49,194
Net operating losses	16,218	13,662
Interest rate swaps	6,752	2,982
Other	411	1,149
Gross deferred tax assets	94,519	77,743
Valuation allowance	(314)	(306)
Net deferred tax assets	94,205	77,437
Deferred tax liabilities:
Investment in solar funds	(648,267)	(483,522)
Fixed asset depreciation and amortization	(29,633)	(31,035)
Gross deferred tax liabilities	(677,900)	(514,557)
Net deferred tax liabilities	$ (583,695)	$ (437,120)

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Contingency [Line Items]
AMT credits	$ 400,000	$ 500,000
Unrecognized tax benefits	957,000	555,000
Unrecognized tax benefits that would impact effective tax rate	900,000	500,000
Unrecognized tax benefits, income tax penalties and interest accrued	0	0
Internal Revenue Service (IRS)
Income Tax Contingency [Line Items]
Federal business tax credits	48,500,000	45,700,000
Internal Revenue Service (IRS) | Prepaid Expenses and Other Current Assets
Income Tax Contingency [Line Items]
Income tax refunds receivable	1,300,000	600,000
Federal
Income Tax Contingency [Line Items]
NOL carryforwards	8,100,000	13,900,000
State
Income Tax Contingency [Line Items]
NOL carryforwards	230,900,000	175,300,000
NOL, Valuation Allowance	300,000	300,000
State | Internal Revenue Service (IRS) | Prepaid Expenses and Other Current Assets
Income Tax Contingency [Line Items]
Income tax refunds receivable	$ 6,900,000	$ 9,300,000
Minimum
Income Tax Contingency [Line Items]
Federal business tax credits, expiration year	2036
Minimum | State
Income Tax Contingency [Line Items]
Operating loss carryforwards expiration year	2029
Maximum
Income Tax Contingency [Line Items]
Federal business tax credits, expiration year	2039
Maximum | State
Income Tax Contingency [Line Items]
Operating loss carryforwards expiration year		2039

Income Taxes - Aggregate Change

Income Taxes - Aggregate Changes in Balance of Gross Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Beginning balance	$ 555
Increases related to positions from a prior year	230	$ 447
Increases related to positions from the current year	172	108
Ending balance	$ 957	$ 555

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Sales and marketing	$ 151,194	$ 58,950
Accounts payable—related party	2,200	200
Accrued equity distributions	10,253	7,846
Vivint Services
Related Party Transaction [Line Items]
Payments made in conjunction with agreements entered	7,100	16,300
Related Party
Related Party Transaction [Line Items]
Sales and marketing	1,800	2,200
Amounts due from direct-sales personnel	6,600	5,200
Provision for advances to direct-sales personnel	400	900
Accrued equity distributions	$ 1,400	$ 1,500

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($)	1 Months Ended		3 Months Ended	12 Months Ended
	Jan. 31, 2020	Feb. 28, 2018	Sep. 30, 2019	Dec. 31, 2019
Other Commitments [Line Items]
Standby letter of credit outstanding				$ 19,600,000
Total estimated obligation earned over deferment period				5,200,000
Percentage of unpaid deferred residual commissions		50.00%
Payment period of deferred residual commission percentage		18 months
Litigation settlement payment	$ 1,000,000
Loss contingency, accrual, current				2,000,000
Sales and Marketing Expense
Other Commitments [Line Items]
Increase in residual commission accrual			$ 5,900,000
General and Administrative
Other Commitments [Line Items]
Litigation settlement payment			$ 1,000,000	2,000,000
General and Administrative | Maximum
Other Commitments [Line Items]
Litigation settlement payment				$ 7,250,000

Basic and Diluted Net Loss Pe_3

Basic and Diluted Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share to Common Stockholders (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net loss attributable to common stockholders	$ (102,175)	$ (15,592)
Denominator:
Shares used in computing net loss attributable per share to common stockholders, basic and diluted	121,310	117,565
Net loss attributable per share to common stockholders:
Basic and diluted	$ (0.84)	$ (0.13)

Basic and Diluted Net Loss Pe_4

Basic and Diluted Net Loss Per Share - Schedule of Shares Excluded from Computation of Net Loss Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total shares	11,692	9,566
RSUs
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total shares	6,271	6,172
Stock Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total shares	5,421	3,394

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) $ in Millions	Feb. 29, 2020USD ($)
Subsequent Event | Wholly Owned Subsidiary
Subsequent Event [Line Items]
Investment fund arrangement, commitment	$ 50