Vivint Solar (VSLR) 10-Q 9 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	May 01, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Trading Symbol	VSLR
Entity Registrant Name	Vivint Solar, Inc.
Entity Central Index Key	0001607716
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		120,611,637

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands		Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents		$ 213,474	$ 219,591
Accounts receivable, net		19,992	14,207
Inventories		11,532	13,257
Prepaid expenses and other current assets		29,294	31,201
Total current assets		274,292	278,256
Restricted cash and cash equivalents		75,010	71,305
Solar energy systems, net		1,590,888	1,938,874
Property and equipment, net		10,180	10,730
Other non-current assets, net		478,013	28,090
TOTAL ASSETS	[1]	2,428,383	2,327,255
Current liabilities:
Accounts payable		38,937	45,929
Distributions payable to non-controlling interests and redeemable non-controlling interests		6,591	7,846
Accrued compensation		21,121	25,520
Current portion of long-term debt		147,952	12,155
Current portion of deferred revenue		26,246	30,199
Current portion of finance lease obligation		769	1,921
Accrued and other current liabilities		49,658	42,860
Total current liabilities		291,274	166,430
Long-term debt, net of current portion		1,123,888	1,203,282
Deferred revenue, net of current portion		14,746	13,524
Finance lease obligation, net of current portion		874	505
Deferred tax liability, net		463,156	437,120
Other non-current liabilities		66,369	24,610
Total liabilities	[1]	1,960,307	1,845,471
Commitments and contingencies (Note 19)
Redeemable non-controlling interests		118,667	119,572
Stockholders’ equity:
Common stock, $0.01 par value—1,000,000 authorized, 120,612 shares issued and outstanding as of March 31, 2019; 1,000,000 authorized, 120,114 shares issued and outstanding as of December 31, 2018		1,206	1,201
Additional paid-in capital		577,961	574,248
Accumulated other comprehensive loss		(11,870)	(7,223)
Accumulated deficit		(306,028)	(279,631)
Total stockholders’ equity		261,269	288,595
Non-controlling interests		88,140	73,617
Total equity		349,409	362,212
TOTAL LIABILITIES, REDEEMABLE NON-CONTROLLING INTERESTS AND EQUITY		$ 2,428,383	$ 2,327,255
[1]	The Company’s assets as of March 31, 2019 and December 31, 2018 include $1,915.2 million and $1,835.8 million consisting of assets of variable interest entities, or VIEs, that can only be used to settle obligations of the VIEs. These assets include solar energy systems, net, of $1,448.0 million and $1,752.3 million as of March 31, 2019 and December 31, 2018; other non-current assets, net of $390.7 million and $10.9 million as of March 31, 2019 and December 31, 2018; cash and cash equivalents of $57.7 million and $62.4 million as of March 31, 2019 and December 31, 2018; accounts receivable, net, of $13.0 million and $6.6 million as of March 31, 2019 and December 31, 2018; restricted cash and cash equivalents of $4.1 million and $2.4 million as of March 31, 2019 and December 31, 2018; and prepaid expenses and other current assets of $1.8 million and $1.3 million as of March 31, 2019 and December 31, 2018. The Company’s liabilities as of March 31, 2019 and December 31, 2018 included $122.2 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 $6.6 million and $7.8 million as of March 31, 2019 and December 31, 2018; deferred revenue of $13.0 million and $12.0 million as of March 31, 2019 and December 31, 2018; long-term debt of $96.4 million and $55.0 million as of March 31, 2019 and December 31, 2018; accrued and other current liabilities of $5.2 million and $4.9 million as of March 31, 2019 and December 31, 2018; and other non-current liabilities of $1.0 million and $1.0 million as of March 31, 2019 and December 31, 2018. For further information see Note 14—Investment Funds.

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands		Mar. 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		120,612,000	120,114,000
Common stock, shares outstanding		120,612,000	120,114,000
Total assets	[1]	$ 2,428,383	$ 2,327,255
Solar energy systems, net		1,590,888	1,938,874
Cash and cash equivalents		213,474	219,591
Accounts receivable, net		19,992	14,207
Other non-current assets, net		478,013	28,090
Restricted cash and cash equivalents		75,010	71,305
Prepaid expenses and other current assets		29,294	31,201
Total liabilities	[1]	1,960,307	1,845,471
Distributions payable to non-controlling interests and redeemable non-controlling interests		6,591	7,846
Accrued and other current liabilities		49,658	42,860
Other non-current liabilities		66,369	24,610
Variable Interest Entities
Total assets		1,915,241	1,835,834
Solar energy systems, net		1,448,012	1,752,271
Cash and cash equivalents		57,660	62,350
Accounts receivable, net		13,033	6,593
Other non-current assets, net		390,711	10,888
Restricted cash and cash equivalents		4,071	2,443
Prepaid expenses and other current assets		1,754	1,289
Total liabilities		122,168	80,760
Distributions payable to non-controlling interests and redeemable non-controlling interests		6,591	7,846
Deferred revenue		13,000	12,000
Long-term debt		96,400	55,000
Accrued and other current liabilities		5,194	4,860
Other non-current liabilities		$ 993	$ 1,023
[1]	The Company’s assets as of March 31, 2019 and December 31, 2018 include $1,915.2 million and $1,835.8 million consisting of assets of variable interest entities, or VIEs, that can only be used to settle obligations of the VIEs. These assets include solar energy systems, net, of $1,448.0 million and $1,752.3 million as of March 31, 2019 and December 31, 2018; other non-current assets, net of $390.7 million and $10.9 million as of March 31, 2019 and December 31, 2018; cash and cash equivalents of $57.7 million and $62.4 million as of March 31, 2019 and December 31, 2018; accounts receivable, net, of $13.0 million and $6.6 million as of March 31, 2019 and December 31, 2018; restricted cash and cash equivalents of $4.1 million and $2.4 million as of March 31, 2019 and December 31, 2018; and prepaid expenses and other current assets of $1.8 million and $1.3 million as of March 31, 2019 and December 31, 2018. The Company’s liabilities as of March 31, 2019 and December 31, 2018 included $122.2 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 $6.6 million and $7.8 million as of March 31, 2019 and December 31, 2018; deferred revenue of $13.0 million and $12.0 million as of March 31, 2019 and December 31, 2018; long-term debt of $96.4 million and $55.0 million as of March 31, 2019 and December 31, 2018; accrued and other current liabilities of $5.2 million and $4.9 million as of March 31, 2019 and December 31, 2018; and other non-current liabilities of $1.0 million and $1.0 million as of March 31, 2019 and December 31, 2018. For further information see Note 14—Investment Funds.

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue:
Total revenue	$ 69,371	$ 68,250
Cost of revenue:
Total cost of revenue	57,454	64,732
Gross profit	11,917	3,518
Operating expenses:
Sales and marketing	29,634	11,125
Research and development	469	486
General and administrative	23,049	19,987
Total operating expenses	53,152	31,598
Loss from operations	(41,235)	(28,080)
Interest expense, net	19,127	16,922
Other expense (income), net	1,385	(2,261)
Loss before income taxes	(61,747)	(42,741)
Income tax expense	27,487	18,643
Net loss	(89,234)	(61,384)
Net loss attributable to non-controlling interests and redeemable non-controlling interests	(62,992)	(48,408)
Net loss attributable to common stockholders	$ (26,242)	$ (12,976)
Net loss per share attributable to common stockholders:
Basic and diluted	$ (0.22)	$ (0.11)
Weighted-average shares used in computing net loss per share attributable to common stockholders:
Basic and diluted	120,307	115,155
Customer Agreements and Incentives
Revenue:
Total revenue	$ 39,603	$ 31,114
Cost of revenue:
Total cost of revenue	40,191	38,687
Solar Energy System and Product Sales
Revenue:
Total revenue	29,768	37,136
Cost of revenue:
Total cost of revenue	$ 17,263	$ 26,045

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net loss attributable to common stockholders	$ (26,242)	$ (12,976)
Other comprehensive (loss) income:
Unrealized (losses) gains on cash flow hedging instruments (net of tax effect of $(1,777) and $1,394)	(4,883)	3,749
Less: Interest (expense) income on derivatives recognized into earnings (net of tax effect of $(86) and $103)	(236)	278
Total other comprehensive (loss) income	(4,647)	3,471
Comprehensive loss	$ (30,889)	$ (9,505)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Unrealized losses on cash flow hedging instruments, tax	$ (1,777)	$ 1,394
Interest expense on derivatives recognized into earnings, tax	$ (86)	$ 103

Condensed Consolidated Statem_4

Condensed 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 (Loss) Income	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	2,969			2,969			2,969
Issuance of common stock, net	207		$ 2	205			207
Issuance of common stock, net (in shares)			230
Contributions from non-controlling interests and redeemable non-controlling interests		42,771
Distributions to non-controlling interests and redeemable non-controlling interests	(7,093)	(2,093)						(7,093)
Total other comprehensive (loss) income	3,471				3,471		3,471
Net loss	(28,369)	(33,015)				(12,976)	(12,976)	(15,393)
Balance at Mar. 31, 2018	358,423	130,107	$ 1,153	562,962	13,694	(277,015)	300,794	57,629
Balance (in Shares) at Mar. 31, 2018			115,329
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	3,679			3,679			3,679
Issuance of common stock, net	39		$ 5	34			39
Issuance of common stock, net (in shares)			498
Contributions from non-controlling interests and redeemable non-controlling interests	74,555	9,813						74,555
Distributions to non-controlling interests and redeemable non-controlling interests	(5,567)	(2,191)						(5,567)
Total other comprehensive (loss) income	(4,647)				(4,647)		(4,647)
Net loss	(80,707)	(8,527)				(26,242)	(26,242)	(54,465)
Balance at Mar. 31, 2019	$ 349,409	$ 118,667	$ 1,206	$ 577,961	$ (11,870)	$ (306,028)	$ 261,269	$ 88,140
Balance (in Shares) at Mar. 31, 2019	120,612		120,612

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (89,234)	$ (61,384)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	17,659	16,443
Deferred income taxes	27,727	18,969
Stock-based compensation	3,679	2,969
Loss on solar energy systems and property and equipment	1,233	570
Non-cash interest and other expense	1,645	2,007
Reduction in lease pass-through financing obligation	(695)	(687)
Losses (gains) on interest rate swaps	1,384	(2,262)
Changes in operating assets and liabilities:
Accounts receivable, net	(5,785)	1,429
Inventories	1,725	6,807
Prepaid expenses and other current assets	2,746	11,746
Other non-current assets, net	(26,539)	385
Accounts payable	1,876	374
Accrued compensation	(4,068)	(2,351)
Deferred revenue	(2,731)	(9,083)
Accrued and other liabilities	(615)	(103)
Net cash used in operating activities	(69,993)	(14,171)
CASH FLOWS FROM INVESTING ACTIVITIES:
Payments for the cost of solar energy systems	(64,526)	(72,208)
Payments for property and equipment	(291)	(40)
Proceeds from disposals of solar energy systems and property and equipment	649	775
Net cash used in investing activities	(64,168)	(71,473)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from investment by non-controlling interests and redeemable non-controlling interests	84,368	42,771
Distributions paid to non-controlling interests and redeemable non-controlling interests	(9,013)	(18,122)
Proceeds from long-term debt	61,355	40,000
Payments on long-term debt	(5,593)	(7,748)
Proceeds from lease pass-through financing obligation	864	852
Principal payments on finance lease obligations	(271)	(1,015)
Proceeds from issuance of common stock	39	207
Net cash provided by financing activities	131,749	56,945
NET DECREASE IN CASH AND CASH EQUIVALENTS, INCLUDING RESTRICTED AMOUNTS	(2,412)	(28,699)
CASH AND CASH EQUIVALENTS, INCLUDING RESTRICTED AMOUNTS—Beginning of period	290,896	154,938
CASH AND CASH EQUIVALENTS, INCLUDING RESTRICTED AMOUNTS—End of period	288,484	126,239
NONCASH INVESTING AND FINANCING ACTIVITIES:
Costs of solar energy systems included in changes in accounts payable, accrued compensation and accrued and other liabilities	40,256	(2,518)
Right-of-use assets obtained in exchange for new operating lease liabilities	6,910
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 1,053	199
Solar energy system sales
NONCASH INVESTING AND FINANCING ACTIVITIES:
Receivable for state tax credits recorded as a reduction to solar energy system costs		$ 4

Organization

Organization	3 Months Ended
	Mar. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	1 . Organization 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 also offers its customers the option to purchase solar energy systems (“System Sales”) through third-party loan offerings or a cash purchase. The Company enters into customer contracts through a sales organization that primarily uses a direct-to-home sales model. The long-term customer contracts under PPAs and Solar Leases are typically for 20 years and require the customer to make monthly payments to the Company. 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	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2 . Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. As such, these unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s annual report on Form 10-K dated as of March 5, 2019. The unaudited condensed consolidated financial statements were prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments (all of which were considered of normal recurring nature) considered necessary to present fairly the Company’s financial results. The results of the three months ended March 31, 2019 are not necessarily indicative of the results to be expected for the fiscal year ending December 31, 2019 or for any other interim period or other future year. The unaudited condensed consolidated financial statements reflect the accounts and operations of the Company and those of its subsidiaries in which the Company has a controlling financial interest. The Company uses a qualitative approach in assessing the consolidation requirement for variable interest entities (“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 and estimates. 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, see Note 14—Investment Funds. The condensed consolidated statements of operations items formerly captioned “Operating leases and incentives” and “Cost of revenue—operating leases and incentives” will now be captioned “Customer agreements and incentives” and “Cost of revenue—customer agreements and incentives” beginning in the current period. The condensed consolidated balance sheet items formerly captioned “Current portion of capital lease obligation” and “Capital lease obligation, net of current portion” will now be captioned “Current portion of finance lease obligation” and “Finance lease obligation, net of current portion” beginning in the current period. Amounts in these balance sheet items were capital leases under ASC 840 in periods ending prior to January 1, 2019, while amounts in these balance sheet items are finance leases under ASC 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 condensed consolidated financial statements requires management to make estimates and assumptions that affect the amounts reported in the condensed 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. 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 its 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. Performance Obligation—Solar Energy system and Product Sales 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 into service. 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 March 31, 2019 and December 31, 2018, the Company had allocated deferred revenue of $3.7 million and $3.3 million to monitoring services that will be recognized over the term of the monitoring services. Leases The Company adopted Accounting Standards Update (“ASU”) 2016-02, 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 condensed consolidated balance sheets as of January 1, 2019. Corresponding lease liabilities of $43.8 million related to operating leases were recognized on the condensed 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 ASC 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 ASC 606. For Solar Leases, the Company concluded that the impact of applying ASC 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 ASC 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 ASC 340 to other non-current assets, net. These costs are now amortized over the period of benefit to sales and marketing expense on the condensed consolidated statements of operations. For purposes of comparison, the following tables show how the balances as of December 31, 2018 and for the three months ended March 31, 2018 would have changed if the effects of adopting Topic 842 had been applied to those balances (in thousands): December 31, 2018 March 31, 2019 As Reported Adjustments As Adjusted As Reported Solar energy systems, net $ 1,938,874 $ (388,087 ) $ 1,550,787 $ 1,590,888 Other non-current assets, net 28,090 388,087 416,177 478,013 Three Months Ended March 31, 2018 2019 As Reported Adjustments As Adjusted As Reported Cost of revenue—customer agreements and incentives $ 38,687 $ (4,080 ) $ 34,607 $ 40,191 Cost of revenue—solar energy system and product sales 26,045 (5,857 ) 20,188 17,263 Total cost of revenue 64,732 (9,937 ) 54,795 57,454 Gross profit 3,518 9,937 13,455 11,917 Sales and marketing 11,125 9,937 21,062 29,634 Total operating expenses 31,598 9,937 41,535 53,152 Software Implementation Costs 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, effective January 1, 2019. This update clarifies that entities should capitalize implementation costs incurred in cloud computing arrangements that are service contracts, which the Company will now record within other non-current assets, net. Entities expense the capitalized costs over the term of the hosting arrangement. The service element of a hosting arrangement that is a service contract is not affected by this update, meaning service costs will continue to be expensed as incurred. The Company is applying the amendments in this update on a prospective basis. No prior periods were impacted as a result of adopting this ASU. Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (the “FASB”) issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. the Company’s accounts receivable are considered financial assets measured at an amortized cost basis and will need to be presented at the net amount expected to be collected. This ASU will be effective for the Company beginning on January 1, 2020 and will be applied through a modified retrospective approach with a cumulative-effect adjustment to retained earnings as of the first reporting period in which the guidance is effective.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	3 . Fair Value Measurements The Company measures and reports its cash equivalents at fair value. The following tables set forth the fair value of the Company’s financial assets and liabilities included on the condensed consolidated balance sheets measured on a recurring basis by level within the fair value hierarchy (in thousands): March 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets Interest rate swaps $ — $ 13 $ — $ 13 Financial Liabilities Interest rate swaps $ — $ 18,751 $ — $ 18,751 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 that 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. The Company has interest rate swaps for its Aggregation Facility, which are not designated as hedges, the fair value of which is represented in financial liabilities above. The Company also has interest rate swaps for its Solar Asset Backed Notes, Series 2018-2, which are designated as hedges, the fair value of which is represented in financial liabilities above. The carrying values and fair values of the Company’s long-term debt were as follows (in thousands): March 31, 2019 December 31, 2018 Carrying Value Fair Value Carrying Value Fair Value Floating-rate long-term debt $ 645,263 $ 645,263 $ 587,358 $ 587,358 Fixed-rate long-term debt 650,888 685,471 653,031 673,917 Total $ 1,296,151 $ 1,330,734 $ 1,240,389 $ 1,261,275 The Company’s outstanding principal balance of long-term debt is carried at cost. 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	3 Months Ended
	Mar. 31, 2019
Inventory Disclosure [Abstract]
Inventories	4 . Inventories Inventories consisted of the following (in thousands): March 31, December 31, 2019 2018 Solar energy systems held for sale $ 10,565 $ 12,321 Photovoltaic installation products 967 936 Total inventories $ 11,532 $ 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 first-in, first-out 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	3 Months Ended
	Mar. 31, 2019
Solar Energy Systems Disclosure [Abstract]
Solar Energy Systems	5 . Solar Energy Systems Solar energy systems, net consisted of the following (in thousands): March 31, December 31, 2019 2018 System equipment costs $ 1,718,400 $ 1,667,440 Initial direct costs related to solar energy systems — 435,084 1,718,400 2,102,524 Less: Accumulated depreciation (162,004 ) (195,890 ) 1,556,396 1,906,634 Solar energy system inventory 34,492 32,240 Solar energy systems, net $ 1,590,888 $ 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 $13.1 million and $15.4 million for the three months ended March 31, 2019 and 2018.

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2019
Property Plant And Equipment [Abstract]
Property and Equipment	6 . Property and Equipment Property and equipment, net consisted of the following (in thousands): Estimated March 31, December 31, Useful Lives 2019 2018 Leasehold improvements 1-12 years $ 10,576 $ 10,560 Furniture and computer and other equipment 3 years 4,030 3,816 Vehicles acquired under finance leases 3-5 years 1,975 6,907 16,581 21,283 Less: Accumulated depreciation and amortization (6,401 ) (10,553 ) Property and equipment, net $ 10,180 $ 10,730 The Company recorded depreciation and amortization expense related to property and equipment of $0.1 million and $1.7 million for the three months ended March 31, 2019 and 2018 . Effective January 1, 2019, the Company adopted Topic 842. As part of the adoption, the Company reassessed all contracts existing at the adoption date. The Company determined that a number of vehicle leases that were previously classified as capital leases under ASC 840 were no longer classified as finance leases under Topic 842. This resulted in a reduction to the gross asset and accumulated depreciation and amortization balances related to vehicles and will result in lower depreciation and amortization expense related to property and equipment compared to prior periods.

Other Non-Current Assets

Other Non-Current Assets	3 Months Ended
	Mar. 31, 2019
Other Assets Noncurrent Disclosure [Abstract]
Other Non-Current Assets	7 . Other Non-Current Assets Other non-current assets consisted of the following (in thousands): March 31, December 31, 2019 2018 Costs to obtain contracts $ 462,495 $ — Accumulated amortization of costs to obtain contracts (50,928 ) — Operating lease right-of-use assets 39,697 — Sales incentives 9,292 8,588 Other non-current assets 17,457 19,502 Total other non-current assets $ 478,013 $ 28,090 The Company recorded amortization of costs to obtain contracts of $3.9 million for the three months ended March 31, 2019. Costs to obtain contracts are amortized over the initial terms of customer contracts, which are typically 20 years.

Intangible Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible Assets	8 . Intangible Assets Net intangible assets are included in other non-current assets, net and consisted of the following (in thousands): March 31, December 31, 2019 2018 Cost: Internal-use software $ 520 $ 1,020 Developed technology 522 522 Trademarks/trade names 201 201 Total carrying value 1,243 1,743 Accumulated amortization: Internal-use software (338 ) (781 ) Developed technology (343 ) (324 ) Trademarks/trade names (105 ) (99 ) Total accumulated amortization (786 ) (1,204 ) Total intangible assets, net $ 457 $ 539 The Company recorded amortization expense of $0.1 million for each of the three-month periods ended March 31, 2019 and 2018, which is included within general and administrative expense on the condensed consolidated statements of operations.

Accrued Compensation

Accrued Compensation	3 Months Ended
	Mar. 31, 2019
Accrued Compensation Disclosure [Abstract]
Accrued Compensation	9 . Accrued Compensation Accrued compensation consisted of the following (in thousands): March 31, December 31, 2019 2018 Accrued payroll $ 12,467 $ 16,352 Accrued commissions 8,654 9,168 Total accrued compensation $ 21,121 $ 25,520

Accrued and Other Current Liabi

Accrued and Other Current Liabilities	3 Months Ended
	Mar. 31, 2019
Payables And Accruals [Abstract]
Accrued and Other Current Liabilities	10 . Accrued and Other Current Liabilities Accrued and other current liabilities consisted of the following (in thousands): March 31, December 31, 2019 2018 Accrued unused commitment fees and interest $ 15,354 $ 14,102 Current portion of operating lease liabilities 6,992 — Accrued professional fees 6,402 6,150 Current portion of lease pass-through financing obligation 5,061 5,038 Accrued workers' compensation 4,459 4,033 Accrued inventory 3,869 4,380 Workmanship accrual 2,648 2,630 Sales, use and property taxes payable 2,618 3,132 Other accrued expenses 2,255 3,395 Total accrued and other current liabilities $ 49,658 $ 42,860

Debt Obligations

Debt Obligations	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Debt Obligations	11 . Debt Obligations Debt obligations consisted of the following as of March 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) $ 462,826 $ (73 ) $ (8,988 ) $ 3,657 $ 450,108 $ — 5.1 % October 2028 Solar asset backed notes, Series 2018-2 (2)(3) 339,382 (6 ) (7,085 ) 294 331,997 — 5.5 August 2023 2017 Term loan facility 186,784 (168 ) (4,524 ) 6,679 175,413 — 6.0 January 2035 Forward flow loan facility 99,780 (42 ) (3,311 ) 1,206 95,221 30,220 4.9 (4) Credit agreement 1,279 (2 ) (112 ) 16 1,149 — 6.5 February 2023 Revolving lines of credit ( 5) Aggregation facility 70,000 — — — 70,000 305,000 5.7 September 2020 Working capital facility ( 6) 136,100 — — 136,100 — — 5.7 March 2020 Total debt $ 1,296,151 $ (291 ) $ (24,020 ) $ 147,952 $ 1,123,888 $ 335,220 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 Forward flow loan facility 58,425 (43 ) (3,365 ) 1,512 53,505 71,575 5.2 (4) 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 comprised 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 comprised 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 $325.2 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 October 31, 2019. (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 March 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 March 31, 2019, the Company had $13.6 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 March 31, 2019, the Company had $25.1 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 March 31, 2019, the Company had $19.7 million in required reserves Forward Flow Loan Facility In August 2018, a subsidiary which is indirectly owned by the Company together with investors, entered into a loan agreement (the “Forward Flow Loan Facility”) pursuant to which the Company may borrow up to an aggregate principal amount of $130.0 million. The borrower may make multiple borrowings under the Forward Flow Loan Facility during the availability period, which will continue no later than October 31, 2019. After the availability period, all outstanding loans under the Forward Flow Loan Facility will be aggregated into a single term loan with a maturity date 20 years after the date of aggregation. Interest on each loan will accrue at an annual rate equal to the U.S. swap rate for the weighted-average life of such loan, plus an applicable margin equal to the greater of (a) 1.9% plus a spread adjustment based on the risk premium on the borrowing date relative to the market index-based risk premium on the closing date and (b) 1.5%. 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 March 31, 2019, the Company had $4.1 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%. Aggregation Facility In September 2014, a wholly owned subsidiary of the Company entered into an aggregation credit facility (as amended, the “Aggregation Facility”), pursuant to which the Company may borrow up to an aggregate of $375.0 million and, upon the satisfaction of certain conditions and the approval of the lenders, up to an additional aggregate of $175.0 million in borrowings. Prepayments are permitted under the Aggregation Facility. Under the Aggregation Facility, interest on borrowings accrues at a floating rate equal to either (1)(a) LIBOR or (b) the greatest of (i) the Federal Funds Rate plus 0.5%, (ii) the administrative agent’s prime rate and (iii) LIBOR plus 1% and (2) a margin that varies between 3.25% during the period during which the Company may incur borrowings and 3.75% after such period. As of March 31, 2019, the Company had $2.4 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 March 2015, a wholly owned subsidiary of the Company entered into a revolving credit agreement (the “Working Capital Facility”) pursuant to which the Company may borrow up to an aggregate principal amount of $150.0 million from certain financial institutions. In addition to the outstanding borrowings as of March 31, 2019, the Company had established letters of credit under the Working Capital Facility for up to $13.9 million related to insurance contracts. Prepayments are permitted under the Working Capital Facility. Interest accrues on borrowings at a floating rate equal to, depending on the type of borrowing, (1) a rate equal to the Eurodollar Rate for the interest period divided by one minus the Eurodollar Reserve Percentage, plus a margin of 3.25%; or (2) the highest of (a) the Federal Funds Rate plus 0.50%, (b) the Citibank prime rate and (c) the one-month interest period Eurodollar rate plus 1.00%, plus a margin of 2.25%. Interest is payable depending on the type of borrowing at the end of (1) the interest period that the Company may elect as a term, not to exceed three months, (2) quarterly or (3) at maturity of the Working Capital Facility. The Company is required to maintain $30.0 million in cash and cash equivalents and certain investments as of the last day of each quarter. As of March 31, 2019, the Company was in compliance with such covenants.

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Lessee Disclosure [Abstract]
Leases	12 . Leases The Company is the lessee in substantially 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 judgements 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): Three Months Ended March 31, 2019 Lease cost Finance lease cost: Amortization of right-of-use assets $ 294 Interest on lease liabilities 26 Operating lease cost 2,770 Short-term lease cost 722 Total lease cost $ 3,812 Other information Finance leases: Operating cash outflows from finance leases $ 26 Financing cash outflows from finance leases $ 271 Right-of-use assets obtained in exchange for new finance lease liabilities $ 1,053 Weighted-average remaining lease term - finance leases (in years) 2.9 Weighted-average discount rate - finance leases 7.8 % Operating leases: Operating cash outflows from operating leases $ 2,826 Right-of-use assets obtained in exchange for new operating lease liabilities $ 6,910 Weighted-average remaining lease term - operating leases (in years) 9.6 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 five 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 March 31, 2019 were as follows (in thousands): 2019 $ 727 2020 387 2021 336 2022 330 2023 52 Thereafter — Total minimum lease payments 1,832 Less: interest 189 Present value of finance lease obligations 1,643 Less: current portion 769 Long-term portion $ 874 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. The Company’s warehouse lease agreements range from a term of one to seven years, with five years being the most common lease term. The warehouse lease agreements typically include options to extend the lease term. The lease agreements 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. 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 March 31, 2019 were as follows (in thousands): 2019 $ 8,032 2020 9,483 2021 7,281 2022 5,595 2023 4,780 Thereafter 36,680 Total minimum lease payments 71,851 Less: present value impact 23,040 Present value of operating lease obligations 48,811 Less: current portion 6,992 Long-term portion $ 41,819

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Mar. 31, 2019
Derivative Instruments And Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	13 . Derivative Financial Instruments Derivative financial instruments at fair value consisted of the following (in thousands): March 31, 2019 Fair Value Balance Sheet Location Derivatives designated as hedging instruments: Interest rate swaps $ 16,222 Other non-current liabilities Derivatives not designated as hedging instruments: Interest rate swaps $ 2,529 Other non-current liabilities Interest rate swaps $ 13 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 relating to its outstanding debt facilities that have variable interest rates. In connection with the March 2017 amendment of the Aggregation Facility, the Company is required to maintain interest rate swaps such that at least 75% of the outstanding loan balance of the Aggregation Facility is hedged. The Company is required to meet this threshold within 15 business days after the end of each quarterly period. As of March 31, 2019, the Company had entered into interest rate swaps with an aggregate notional amount of $40.0 million. The Company entered the required swaps subsequent to period end and is in compliance with the hedging requirement. The interest rate swaps terminate when the Aggregation Facility matures in September 2020. 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 March 31, 2019, the notional amount of these interest rate swaps was $325.2 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 other comprehensive income (“OCI”). The amount of accumulated other comprehensive (loss) income (“AOCI”) expected to be reclassified to interest expense within the next 12 months is approximately $1.8 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 (gains) on derivatives designated as cash flow hedges recognized in OCI, before tax effect, consisted of the following (in thousands): Three Months Ended March 31, 2019 2018 Derivatives designated as cash flow hedges: Interest rate swaps $ 6,660 $ (5,143 ) The losses (gains) on derivative financial instruments recognized in the condensed consolidated statements of operations, before tax effect, consisted of the following (in thousands): Three Months Ended March 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 $ 19,127 $ 1,385 $ 16,922 $ (2,261 ) Derivatives designated as cash flow hedges: Interest rate swaps Losses (gains) reclassified from AOCI into income $ 322 $ — $ (381 ) $ — Derivatives not designated as hedging instruments: Interest rate swaps Losses (gains) recognized in income — 1,384 — (2,262 ) Total losses (gains) $ 322 $ 1,384 $ (381 ) $ (2,262 )

Investment Funds

Investment Funds	3 Months Ended
	Mar. 31, 2019
Summarized Financial Data Of Subsidiary [Abstract]
Investment Funds	14 . Investment Funds As of March 31, 2019 and December 31, 2018, the Company had formed investment funds for the purpose of funding the purchase of solar energy systems under long-term customer contracts. The aggregate carrying value of these funds’ assets and liabilities (after elimination of intercompany transactions and balances) in the Company’s condensed consolidated balance sheets were as follows (in thousands): March 31, December 31, 2019 2018 Assets Current assets: Cash and cash equivalents $ 57,660 $ 62,350 Accounts receivable, net 13,033 6,593 Prepaid expenses and other current assets 1,754 1,289 Total current assets 72,447 70,232 Restricted cash and cash equivalents 4,071 2,443 Solar energy systems, net 1,448,012 1,752,271 Other non-current assets, net 390,711 10,888 Total assets $ 1,915,241 $ 1,835,834 Liabilities Current liabilities: Distributions payable to non-controlling interests and redeemable non-controlling interests $ 6,591 $ 7,846 Current portion of long-term debt 1,206 1,512 Current portion of deferred revenue 2,411 2,320 Accrued and other current liabilities 5,194 4,860 Total current liabilities 15,402 16,538 Long-term debt, net of current portion 95,221 53,505 Deferred revenue, net of current portion 10,552 9,694 Other non-current liabilities 993 1,023 Total liabilities $ 122,168 $ 80,760 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 March 31, 2019 and December 31, 2018, the cumulative total of contributions into the VIEs by all investors was $1,649.7 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 $45.2 million and $55.8 million as of March 31, 2019 and December 31, 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 condensed 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 March 31, 2019 and December 31, 2018, the Company had recorded financing liabilities of $5.3 million for each period related to this fund arrangement, which represents 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 condensed 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 Internal Revenue Service (“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 March 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 $7.9 million and $8.3 million as of March 31, 2019 and December 31, 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. No distributions were paid to reimburse fund investors during the three months ended March 31, 2019. As of March 31, 2019, 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 March 31, 2019 and December 31, 2018, which is classified as restricted cash and cash equivalents.

Redeemable Non-Controlling Inte

Redeemable Non-Controlling Interests and Equity	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Redeemable Non-Controlling Interests and Equity	15 . Redeemable Non-Controlling Interests and Equity Common Stock The Company had shares of common stock reserved for issuance as follows (in thousands): March 31, December 31, 2019 2018 Shares available for grant under equity incentive plans 15,346 13,323 Restricted stock units issued and outstanding 6,809 6,172 Stock options issued and outstanding 5,041 3,394 Long-term incentive plan 2,706 2,706 Total 29,902 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 hypothetical liquidation at book value (“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.

Equity Compensation Plans

Equity Compensation Plans	3 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Compensation Plans	16 . Equity Compensation Plans 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 March 31, 2019, a total of 15.3 million shares of common stock were available to grant under the 2014 Plan, subject to adjustment in the case of certain events. The number of shares available to grant under the 2014 Plan is subject to an annual increase on the first day of each year. In accordance with the annual increase, an additional 4.8 million shares became available to grant in January 2019 under the 2014 Plan. Stock Options Stock Option Activity Stock option activity for the three months ended March 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 1,657 4.64 Exercised (10 ) 3.69 Cancelled — — Outstanding—March 31, 2019 5,041 $ 3.38 7.9 $ 8,889 Options vested and exercisable—March 31, 2019 1,815 $ 2.42 6.0 $ 5,226 RSUs RSU activity for the three months ended March 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 1,206 4.62 Vested (487 ) 3.85 Forfeited (82 ) 3.72 Outstanding at March 31, 2019 6,809 $ 3.98 Stock-Based Compensation Expense Stock-based compensation was included in operating expenses as follows (in thousands): Three Months Ended March 31, 2019 2018 Cost of revenue $ 332 $ 274 Sales and marketing 735 831 General and administrative 2,584 1,820 Research and development 28 44 Total stock-based compensation $ 3,679 $ 2,969 Unrecognized stock-based compensation expense for RSUs and stock options as of March 31, 2019 was as follows (in thousands, except years): Unrecognized Weighted- Stock-Based Average Period Compensation of Recognition Expense (in years) RSUs $ 17,646 1.8 Stock options 6,162 2.3 Total unrecognized stock-based compensation expense $ 23,808

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	17 . Income Taxes The income tax expense for the three months ended March 31, 2019 and 2018 was calculated on a discrete basis resulting in a consolidated quarterly effective income tax rate of (44.5)% and (43.6)%. The variations between the consolidated effective income tax rate and the U.S. federal statutory rate for the three months ended March 31, 2019 and 2018 were primarily attributable to the tax gains recognized on the sale of solar energy systems to investment funds and non-controlling interests and redeemable non-controlling interests. The Company sells solar energy systems to its 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 condensed 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 as a component of income tax expense during the period in which the transfers occur.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2019
Related Party Transactions [Abstract]
Related Party Transactions	18 . Related Party Transactions The Company’s condensed consolidated statements of operations included related party transactions of $0.8 million and $0.7 million within sales and marketing for the three months ended March 31, 2019 and 2018. Vivint Services The Company has negotiated and entered into a number of agreements with its sister company, Vivint, Inc. (“Vivint”). In August 2017, the Company entered into 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 has an initial term of two years and replaces substantially all of the activities being undertaken under the parties’ former marketing and customer relations agreement. The Company and Vivint also agreed to extend the term of the non-solicitation provisions under an existing non-competition agreement to match the term of the sales dealer agreement. The Company incurred fees under agreements with Vivint of $2.4 million and $1.0 million for the three months ended March 31, 2019 and 2018. These amounts reflect the level of services provided by Vivint on behalf of the Company. Payables to Vivint recorded in accounts payable were $0.1 million and $0.2 million as of March 31, 2019 and December 31, 2018. These payables include amounts due to Vivint related primarily to the sales dealer agreement. Advances Receivable — Net amounts due from direct-sales personnel were $4.0 million and $5.2 million as of March 31, 2019 and December 31, 2018. The Company provided a reserve of $1.0 million and $0.9 million as of March 31, 2019 and December 31, 2018 related to advances to direct-sales personnel who have terminated their employment agreement with the Company. 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 $1.1 million and $1.5 million as of March 31, 2019 and December 31, 2018, included in distributions payable to non-controlling and redeemable non-controlling interests. See Note 14—Investment Funds.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	19 . Commitments and Contingencies Non-Cancellable Operating Leases See Note 12—Leases for details regarding the Company’s lease arrangements. Letters of Credit As of March 31, 2019, the Company had established letters of credit under the Working Capital Facility for up to $13.9 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 representatives on a deferred basis. The amount deferred is based on the value of the system sold by the sales representative and payment is based on the sales representative 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 representative 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 March 31, 2019, the total estimated obligation that is currently not recorded in the Company’s condensed consolidated financial statements, but that will be earned and expensed over the deferment period was $16.2 million. Legal Proceedings In March 2016, the Company filed suit in the Court of Chancery State of Delaware against SunEdison and SEV Merger Sub Inc. alleging that SunEdison willfully breached its obligations under the Merger Agreement pursuant to which the Company was to be acquired and breached its implied covenant of good faith and fair dealing. In April 2016, SunEdison filed for Chapter 11 bankruptcy, which stayed prosecution of the Company’s litigation in the Delaware court. In September 2016, the Company submitted a proof of claim in the bankruptcy case for an unsecured claim in the initial amount of $1.0 billion, which was subject to dispute, for damages for breach of the Merger Agreement. In April 2018, the Company reached a settlement with the litigation trustee in the bankruptcy case under which the Company’s claim will be allowed in the amount of $590.0 million. This settlement resolves both the lawsuit in the Delaware Chancery Court and the dispute about the amount of the Company’s unsecured creditor claim in the bankruptcy. In April 2018, the Company received an initial distribution of $2.1 million and expects to receive further distributions as assets are distributed to unsecured creditors under the court-approved plan of reorganization in the SunEdison bankruptcy case. While the exact amount to be distributed for this claim is unknown at this time, the payout is expected to be a small fraction of the $590.0 million claim. In February 2018, two former employees, on behalf of themselves and a purported class, named the Company in a putative class action 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. 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 or periods in which any such outcome becomes probable and estimable. In March 2018, the New Mexico Attorney General’s office filed an action against the Company and several of its officers 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. The Company is unable to estimate the amount or range of potential loss, if any, at this time. In October 2018, a former employee filed a representative action 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 representative filed a representative action 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 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 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 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	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Share	20 . Basic and Diluted Net Loss Per Share The following table sets forth the computation of the Company’s basic and diluted net loss attributable per share to common stockholders for three months ended March 31, 2019 and 2018 (in thousands, except per share amounts): Three Months Ended March 31, 2019 2018 Numerator: Net loss attributable to common stockholders $ (26,242 ) $ (12,976 ) Denominator: Shares used in computing net loss attributable per share to common stockholders, basic 120,307 115,155 Weighted-average effect of potentially dilutive shares to purchase common stock — — Shares used in computing net loss attributable per share to common stockholders, diluted 120,307 115,155 Net loss per share attributable to common stockholders: Basic and diluted $ (0.22 ) $ (0.11 ) For the three months ended March 31, 2019 and 2018, the Company incurred net losses attributable to common stockholders. As such, the potentially dilutive shares were anti-dilutive and were not considered in the weighted-average number of common shares outstanding for either period.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (“SEC”) regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. As such, these unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and accompanying notes included in the Company’s annual report on Form 10-K dated as of March 5, 2019. The unaudited condensed consolidated financial statements were prepared on the same basis as the audited consolidated financial statements and, in the opinion of management, reflect all adjustments (all of which were considered of normal recurring nature) considered necessary to present fairly the Company’s financial results. The results of the three months ended March 31, 2019 are not necessarily indicative of the results to be expected for the fiscal year ending December 31, 2019 or for any other interim period or other future year. The unaudited condensed consolidated financial statements reflect the accounts and operations of the Company and those of its subsidiaries in which the Company has a controlling financial interest. The Company uses a qualitative approach in assessing the consolidation requirement for variable interest entities (“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 and estimates. 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, see Note 14—Investment Funds. The condensed consolidated statements of operations items formerly captioned “Operating leases and incentives” and “Cost of revenue—operating leases and incentives” will now be captioned “Customer agreements and incentives” and “Cost of revenue—customer agreements and incentives” beginning in the current period. The condensed consolidated balance sheet items formerly captioned “Current portion of capital lease obligation” and “Capital lease obligation, net of current portion” will now be captioned “Current portion of finance lease obligation” and “Finance lease obligation, net of current portion” beginning in the current period. Amounts in these balance sheet items were capital leases under ASC 840 in periods ending prior to January 1, 2019, while amounts in these balance sheet items are finance leases under ASC 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 condensed consolidated financial statements requires management to make estimates and assumptions that affect the amounts reported in the condensed 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.
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 its 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.
Performance Obligation—Solar Energy System and Product Sales	Performance Obligation—Solar Energy system and Product Sales 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 into service. 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 March 31, 2019 and December 31, 2018, the Company had allocated deferred revenue of $3.7 million and $3.3 million to monitoring services that will be recognized over the term of the monitoring services.
Leases	Leases The Company adopted Accounting Standards Update (“ASU”) 2016-02, 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 condensed consolidated balance sheets as of January 1, 2019. Corresponding lease liabilities of $43.8 million related to operating leases were recognized on the condensed 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 ASC 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 ASC 606. For Solar Leases, the Company concluded that the impact of applying ASC 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 ASC 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 ASC 340 to other non-current assets, net. These costs are now amortized over the period of benefit to sales and marketing expense on the condensed consolidated statements of operations. For purposes of comparison, the following tables show how the balances as of December 31, 2018 and for the three months ended March 31, 2018 would have changed if the effects of adopting Topic 842 had been applied to those balances (in thousands): December 31, 2018 March 31, 2019 As Reported Adjustments As Adjusted As Reported Solar energy systems, net $ 1,938,874 $ (388,087 ) $ 1,550,787 $ 1,590,888 Other non-current assets, net 28,090 388,087 416,177 478,013 Three Months Ended March 31, 2018 2019 As Reported Adjustments As Adjusted As Reported Cost of revenue—customer agreements and incentives $ 38,687 $ (4,080 ) $ 34,607 $ 40,191 Cost of revenue—solar energy system and product sales 26,045 (5,857 ) 20,188 17,263 Total cost of revenue 64,732 (9,937 ) 54,795 57,454 Gross profit 3,518 9,937 13,455 11,917 Sales and marketing 11,125 9,937 21,062 29,634 Total operating expenses 31,598 9,937 41,535 53,152
Software Implementation Costs	Software Implementation Costs 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, effective January 1, 2019. This update clarifies that entities should capitalize implementation costs incurred in cloud computing arrangements that are service contracts, which the Company will now record within other non-current assets, net. Entities expense the capitalized costs over the term of the hosting arrangement. The service element of a hosting arrangement that is a service contract is not affected by this update, meaning service costs will continue to be expensed as incurred. The Company is applying the amendments in this update on a prospective basis. No prior periods were impacted as a result of adopting this ASU.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In June 2016, the Financial Accounting Standards Board (the “FASB”) issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. the Company’s accounts receivable are considered financial assets measured at an amortized cost basis and will need to be presented at the net amount expected to be collected. This ASU will be effective for the Company beginning on January 1, 2020 and will be applied through a modified retrospective approach with a cumulative-effect adjustment to retained earnings as of the first reporting period in which the guidance is effective.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 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 three months ended March 31, 2018 would have changed if the effects of adopting Topic 842 had been applied to those balances (in thousands): December 31, 2018 March 31, 2019 As Reported Adjustments As Adjusted As Reported Solar energy systems, net $ 1,938,874 $ (388,087 ) $ 1,550,787 $ 1,590,888 Other non-current assets, net 28,090 388,087 416,177 478,013 Three Months Ended March 31, 2018 2019 As Reported Adjustments As Adjusted As Reported Cost of revenue—customer agreements and incentives $ 38,687 $ (4,080 ) $ 34,607 $ 40,191 Cost of revenue—solar energy system and product sales 26,045 (5,857 ) 20,188 17,263 Total cost of revenue 64,732 (9,937 ) 54,795 57,454 Gross profit 3,518 9,937 13,455 11,917 Sales and marketing 11,125 9,937 21,062 29,634 Total operating expenses 31,598 9,937 41,535 53,152

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Assets and Liabilities Measured on Recurring Basis	The Company measures and reports its cash equivalents at fair value. The following tables set forth the fair value of the Company’s financial assets and liabilities included on the condensed consolidated balance sheets measured on a recurring basis by level within the fair value hierarchy (in thousands): March 31, 2019 Level 1 Level 2 Level 3 Total Financial Assets Interest rate swaps $ — $ 13 $ — $ 13 Financial Liabilities Interest rate swaps $ — $ 18,751 $ — $ 18,751 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): March 31, 2019 December 31, 2018 Carrying Value Fair Value Carrying Value Fair Value Floating-rate long-term debt $ 645,263 $ 645,263 $ 587,358 $ 587,358 Fixed-rate long-term debt 650,888 685,471 653,031 673,917 Total $ 1,296,151 $ 1,330,734 $ 1,240,389 $ 1,261,275

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2019
Inventory Disclosure [Abstract]
Summary of Inventories	Inventories consisted of the following (in thousands): March 31, December 31, 2019 2018 Solar energy systems held for sale $ 10,565 $ 12,321 Photovoltaic installation products 967 936 Total inventories $ 11,532 $ 13,257

Solar Energy Systems (Tables)

Solar Energy Systems (Tables)	3 Months Ended
	Mar. 31, 2019
Solar Energy Systems Disclosure [Abstract]
Solar Energy Systems	Solar energy systems, net consisted of the following (in thousands): March 31, December 31, 2019 2018 System equipment costs $ 1,718,400 $ 1,667,440 Initial direct costs related to solar energy systems — 435,084 1,718,400 2,102,524 Less: Accumulated depreciation (162,004 ) (195,890 ) 1,556,396 1,906,634 Solar energy system inventory 34,492 32,240 Solar energy systems, net $ 1,590,888 $ 1,938,874

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2019
Property Plant And Equipment [Abstract]
Summary of Property and Equipment Net	Property and equipment, net consisted of the following (in thousands): Estimated March 31, December 31, Useful Lives 2019 2018 Leasehold improvements 1-12 years $ 10,576 $ 10,560 Furniture and computer and other equipment 3 years 4,030 3,816 Vehicles acquired under finance leases 3-5 years 1,975 6,907 16,581 21,283 Less: Accumulated depreciation and amortization (6,401 ) (10,553 ) Property and equipment, net $ 10,180 $ 10,730

Other Non-Current Assets (Table

Other Non-Current Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Other Assets Noncurrent Disclosure [Abstract]
Schedule of Other Non-Current Assets	Other non-current assets consisted of the following (in thousands): March 31, December 31, 2019 2018 Costs to obtain contracts $ 462,495 $ — Accumulated amortization of costs to obtain contracts (50,928 ) — Operating lease right-of-use assets 39,697 — Sales incentives 9,292 8,588 Other non-current assets 17,457 19,502 Total other non-current assets $ 478,013 $ 28,090

Intangible Assets (Tables)

Intangible Assets (Tables)	3 Months Ended
	Mar. 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): March 31, December 31, 2019 2018 Cost: Internal-use software $ 520 $ 1,020 Developed technology 522 522 Trademarks/trade names 201 201 Total carrying value 1,243 1,743 Accumulated amortization: Internal-use software (338 ) (781 ) Developed technology (343 ) (324 ) Trademarks/trade names (105 ) (99 ) Total accumulated amortization (786 ) (1,204 ) Total intangible assets, net $ 457 $ 539

Accrued Compensation (Tables)

Accrued Compensation (Tables)	3 Months Ended
	Mar. 31, 2019
Accrued Compensation Disclosure [Abstract]
Summary of Accrued Compensation	Accrued compensation consisted of the following (in thousands): March 31, December 31, 2019 2018 Accrued payroll $ 12,467 $ 16,352 Accrued commissions 8,654 9,168 Total accrued compensation $ 21,121 $ 25,520

Accrued and Other Current Lia_2

Accrued and Other Current Liabilities (Tables)	3 Months Ended
	Mar. 31, 2019
Payables And Accruals [Abstract]
Schedule of Accrued and Other Current Liabilities	Accrued and other current liabilities consisted of the following (in thousands): March 31, December 31, 2019 2018 Accrued unused commitment fees and interest $ 15,354 $ 14,102 Current portion of operating lease liabilities 6,992 — Accrued professional fees 6,402 6,150 Current portion of lease pass-through financing obligation 5,061 5,038 Accrued workers' compensation 4,459 4,033 Accrued inventory 3,869 4,380 Workmanship accrual 2,648 2,630 Sales, use and property taxes payable 2,618 3,132 Other accrued expenses 2,255 3,395 Total accrued and other current liabilities $ 49,658 $ 42,860

Debt Obligations (Tables)

Debt Obligations (Tables)	3 Months Ended
	Mar. 31, 2019
Debt Disclosure [Abstract]
Schedule of Debt	Debt obligations consisted of the following as of March 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) $ 462,826 $ (73 ) $ (8,988 ) $ 3,657 $ 450,108 $ — 5.1 % October 2028 Solar asset backed notes, Series 2018-2 (2)(3) 339,382 (6 ) (7,085 ) 294 331,997 — 5.5 August 2023 2017 Term loan facility 186,784 (168 ) (4,524 ) 6,679 175,413 — 6.0 January 2035 Forward flow loan facility 99,780 (42 ) (3,311 ) 1,206 95,221 30,220 4.9 (4) Credit agreement 1,279 (2 ) (112 ) 16 1,149 — 6.5 February 2023 Revolving lines of credit ( 5) Aggregation facility 70,000 — — — 70,000 305,000 5.7 September 2020 Working capital facility ( 6) 136,100 — — 136,100 — — 5.7 March 2020 Total debt $ 1,296,151 $ (291 ) $ (24,020 ) $ 147,952 $ 1,123,888 $ 335,220 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 Forward flow loan facility 58,425 (43 ) (3,365 ) 1,512 53,505 71,575 5.2 (4) 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 comprised 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 comprised 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 $325.2 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 October 31, 2019. (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.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 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): Three Months Ended March 31, 2019 Lease cost Finance lease cost: Amortization of right-of-use assets $ 294 Interest on lease liabilities 26 Operating lease cost 2,770 Short-term lease cost 722 Total lease cost $ 3,812 Other information Finance leases: Operating cash outflows from finance leases $ 26 Financing cash outflows from finance leases $ 271 Right-of-use assets obtained in exchange for new finance lease liabilities $ 1,053 Weighted-average remaining lease term - finance leases (in years) 2.9 Weighted-average discount rate - finance leases 7.8 % Operating leases: Operating cash outflows from operating leases $ 2,826 Right-of-use assets obtained in exchange for new operating lease liabilities $ 6,910 Weighted-average remaining lease term - operating leases (in years) 9.6 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 March 31, 2019 were as follows (in thousands): 2019 $ 727 2020 387 2021 336 2022 330 2023 52 Thereafter — Total minimum lease payments 1,832 Less: interest 189 Present value of finance lease obligations 1,643 Less: current portion 769 Long-term portion $ 874
Schedule of Future Minimum Lease Payments Under Non-cancellable Operating Leases	Future minimum lease payments under non-cancellable operating leases as of March 31, 2019 were as follows (in thousands): 2019 $ 8,032 2020 9,483 2021 7,281 2022 5,595 2023 4,780 Thereafter 36,680 Total minimum lease payments 71,851 Less: present value impact 23,040 Present value of operating lease obligations 48,811 Less: current portion 6,992 Long-term portion $ 41,819

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	3 Months Ended
	Mar. 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): March 31, 2019 Fair Value Balance Sheet Location Derivatives designated as hedging instruments: Interest rate swaps $ 16,222 Other non-current liabilities Derivatives not designated as hedging instruments: Interest rate swaps $ 2,529 Other non-current liabilities Interest rate swaps $ 13 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 Company records derivatives at fair value. The losses (gains) on derivatives designated as cash flow hedges recognized in OCI, before tax effect, consisted of the following (in thousands): Three Months Ended March 31, 2019 2018 Derivatives designated as cash flow hedges: Interest rate swaps $ 6,660 $ (5,143 ) The losses (gains) on derivative financial instruments recognized in the condensed consolidated statements of operations, before tax effect, consisted of the following (in thousands): Three Months Ended March 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 $ 19,127 $ 1,385 $ 16,922 $ (2,261 ) Derivatives designated as cash flow hedges: Interest rate swaps Losses (gains) reclassified from AOCI into income $ 322 $ — $ (381 ) $ — Derivatives not designated as hedging instruments: Interest rate swaps Losses (gains) recognized in income — 1,384 — (2,262 ) Total losses (gains) $ 322 $ 1,384 $ (381 ) $ (2,262 )

Investment Funds (Tables)

Investment Funds (Tables)	3 Months Ended
	Mar. 31, 2019
Schedule Of Investments [Abstract]
Aggregate Carrying Value of Funds Assets and Liabilities	As of March 31, 2019 and December 31, 2018, the Company had formed investment funds for the purpose of funding the purchase of solar energy systems under long-term customer contracts. The aggregate carrying value of these funds’ assets and liabilities (after elimination of intercompany transactions and balances) in the Company’s condensed consolidated balance sheets were as follows (in thousands): March 31, December 31, 2019 2018 Assets Current assets: Cash and cash equivalents $ 57,660 $ 62,350 Accounts receivable, net 13,033 6,593 Prepaid expenses and other current assets 1,754 1,289 Total current assets 72,447 70,232 Restricted cash and cash equivalents 4,071 2,443 Solar energy systems, net 1,448,012 1,752,271 Other non-current assets, net 390,711 10,888 Total assets $ 1,915,241 $ 1,835,834 Liabilities Current liabilities: Distributions payable to non-controlling interests and redeemable non-controlling interests $ 6,591 $ 7,846 Current portion of long-term debt 1,206 1,512 Current portion of deferred revenue 2,411 2,320 Accrued and other current liabilities 5,194 4,860 Total current liabilities 15,402 16,538 Long-term debt, net of current portion 95,221 53,505 Deferred revenue, net of current portion 10,552 9,694 Other non-current liabilities 993 1,023 Total liabilities $ 122,168 $ 80,760

Redeemable Non-Controlling In_2

Redeemable Non-Controlling Interests and Equity (Tables)	3 Months Ended
	Mar. 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): March 31, December 31, 2019 2018 Shares available for grant under equity incentive plans 15,346 13,323 Restricted stock units issued and outstanding 6,809 6,172 Stock options issued and outstanding 5,041 3,394 Long-term incentive plan 2,706 2,706 Total 29,902 25,595

Equity Compensation Plans (Tabl

Equity Compensation Plans (Tables)	3 Months Ended
	Mar. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	Stock option activity for the three months ended March 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 1,657 4.64 Exercised (10 ) 3.69 Cancelled — — Outstanding—March 31, 2019 5,041 $ 3.38 7.9 $ 8,889 Options vested and exercisable—March 31, 2019 1,815 $ 2.42 6.0 $ 5,226
RSU Activity	RSU activity for the three months ended March 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 1,206 4.62 Vested (487 ) 3.85 Forfeited (82 ) 3.72 Outstanding at March 31, 2019 6,809 $ 3.98
Summary of Stock-Based Compensation Expense	Stock-based compensation was included in operating expenses as follows (in thousands): Three Months Ended March 31, 2019 2018 Cost of revenue $ 332 $ 274 Sales and marketing 735 831 General and administrative 2,584 1,820 Research and development 28 44 Total stock-based compensation $ 3,679 $ 2,969
Summary of Unrecognized Stock-Based Compensation Expense	Unrecognized stock-based compensation expense for RSUs and stock options as of March 31, 2019 was as follows (in thousands, except years): Unrecognized Weighted- Stock-Based Average Period Compensation of Recognition Expense (in years) RSUs $ 17,646 1.8 Stock options 6,162 2.3 Total unrecognized stock-based compensation expense $ 23,808

Basic and Diluted Net Loss Pe_2

Basic and Diluted Net Loss Per Share (Tables)	3 Months Ended
	Mar. 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 three months ended March 31, 2019 and 2018 (in thousands, except per share amounts): Three Months Ended March 31, 2019 2018 Numerator: Net loss attributable to common stockholders $ (26,242 ) $ (12,976 ) Denominator: Shares used in computing net loss attributable per share to common stockholders, basic 120,307 115,155 Weighted-average effect of potentially dilutive shares to purchase common stock — — Shares used in computing net loss attributable per share to common stockholders, diluted 120,307 115,155 Net loss per share attributable to common stockholders: Basic and diluted $ (0.22 ) $ (0.11 )

Organization - Additional Infor

Organization - Additional Information (Details)	3 Months Ended
	Mar. 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) - USD ($) $ in Thousands	Jan. 01, 2019	Mar. 31, 2019	Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items]
Operating leases right-of-use assets		$ 39,697
Operating leases lease liabilities		48,811
Operating leases liabilities removed from current liabilities	$ 1,000
Monitoring Services
Summary Of Significant Accounting Policies [Line Items]
Deferred revenue		$ 3,700	$ 3,300
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit	200
Short term leases right of use asset	0
Short term lease liability	0
Operating leases right-of-use assets	34,600
Operating leases lease liabilities	43,800
Operating leases liabilities removed from non current liabilities	8,200
Finance lease right-of-use assets	$ 900

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Summary of Comparison on Effects of Adopting Topic 842 (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items]
Solar energy systems, net	$ 1,590,888		$ 1,938,874
Other non-current assets, net	478,013		28,090
Total cost of revenue	57,454	$ 64,732
Gross profit	11,917	3,518
Sales and marketing	29,634	11,125
Total operating expenses	53,152	31,598
Customer Agreements and Incentives
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue	40,191	38,687
Solar Energy System and Product Sales
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue	$ 17,263	26,045
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		54,795
Gross profit		13,455
Sales and marketing		21,062
Total operating expenses		41,535
ASU 2016-02 | Customer Agreements and Incentives
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue		34,607
ASU 2016-02 | Solar Energy System and Product Sales
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue		20,188
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		(9,937)
Gross profit		9,937
Sales and marketing		9,937
Total operating expenses		9,937
Adjustments | ASU 2016-02 | Customer Agreements and Incentives
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue		(4,080)
Adjustments | ASU 2016-02 | Solar Energy System and Product Sales
Summary Of Significant Accounting Policies [Line Items]
Total cost of revenue		$ (5,857)

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	Mar. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial Assets	$ 13	$ 130
Financial Liabilities	18,751	11,146
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Financial Assets	13	130
Financial Liabilities	$ 18,751	$ 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	Mar. 31, 2019	Dec. 31, 2018
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, Carrying Value	$ 1,296,151	$ 1,240,389
Long-term debt, Fair Value	1,330,734	1,261,275
Floating-rate Long-term Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, Carrying Value	645,263	587,358
Long-term debt, Fair Value	645,263	587,358
Fixed-rate Long-term Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Long-term debt, Carrying Value	650,888	653,031
Long-term debt, Fair Value	$ 685,471	$ 673,917

Inventories - Summary of Invent

Inventories - Summary of Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Solar energy systems held for sale	$ 10,565	$ 12,321
Photovoltaic installation products	967	936
Total inventories	$ 11,532	$ 13,257

Solar Energy Systems (Details)

Solar Energy Systems (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Capitalized Costs of Equipment Installed Under Customer Agreements [Line Items]
Solar energy systems, gross	$ 1,718,400	$ 2,102,524
Less: Accumulated depreciation	(162,004)	(195,890)
Solar energy systems, net excluding inventory	1,556,396	1,906,634
Solar energy system inventory	34,492	32,240
Solar energy systems, net	1,590,888	1,938,874
System Equipment Costs
Capitalized Costs of Equipment Installed Under Customer Agreements [Line Items]
Solar energy systems, gross	$ 1,718,400	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 ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
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	$ 13,100,000	$ 15,400,000

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Property Plant And Equipment [Line Items]
Property, gross	$ 16,581	$ 21,283
Less: Accumulated depreciation and amortization	(6,401)	(10,553)
Property and equipment, net	10,180	10,730
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property, gross	$ 10,576	10,560
Furniture and Computer and Other Equipment
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Lives	3 years
Property, gross	$ 4,030	3,816
Vehicles Acquired Under Finance Leases
Property Plant And Equipment [Line Items]
Property, gross	$ 1,975	$ 6,907
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
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	5 years

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Property Plant And Equipment [Line Items]
Depreciation and amortization expense	$ 17,659	$ 16,443
Property and equipment
Property Plant And Equipment [Line Items]
Depreciation and amortization expense	$ 100	$ 1,700

Other Non-Current Assets - Sche

Other Non-Current Assets - Schedule of Other Non-Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other Assets Noncurrent [Abstract]
Costs to obtain contracts	$ 462,495
Accumulated amortization of costs to obtain contracts	(50,928)
Operating lease right-of-use assets	39,697
Sales incentives	9,292	$ 8,588
Other non-current assets	17,457	19,502
Total other non-current assets	$ 478,013	$ 28,090

Other Non-Current Assets - Addi

Other Non-Current Assets - Additional Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Other Assets Noncurrent [Abstract]
Amortization of costs to obtain contracts	$ 3.9
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	Mar. 31, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Intangible assets, carrying value	$ 1,243	$ 1,743
Intangible assets, accumulated amortization	(786)	(1,204)
Total intangible assets, net	457	539
Internal-use software
Finite Lived Intangible Assets [Line Items]
Intangible assets, carrying value	520	1,020
Intangible assets, accumulated amortization	(338)	(781)
Developed Technology
Finite Lived Intangible Assets [Line Items]
Intangible assets, carrying value	522	522
Intangible assets, accumulated amortization	(343)	(324)
Trademarks/Trade Names
Finite Lived Intangible Assets [Line Items]
Intangible assets, carrying value	201	201
Intangible assets, accumulated amortization	$ (105)	$ (99)

Intangible Assets - Additional

Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 0.1	$ 0.1

Accrued Compensation - Summary

Accrued Compensation - Summary of Accrued Compensation (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Accrued Compensation Disclosure [Abstract]
Accrued payroll	$ 12,467	$ 16,352
Accrued commissions	8,654	9,168
Total accrued compensation	$ 21,121	$ 25,520

Accrued and Other Current Lia_3

Accrued and Other Current Liabilities - Schedule of Accrued and Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Accrued unused commitment fees and interest	$ 15,354	$ 14,102
Current portion of operating lease liabilities	6,992
Accrued professional fees	6,402	6,150
Current portion of lease pass-through financing obligation	5,061	5,038
Accrued workers' compensation	4,459	4,033
Accrued inventory	3,869	4,380
Workmanship accrual	2,648	2,630
Sales, use and property taxes payable	2,618	3,132
Other accrued expenses	2,255	3,395
Total accrued and other current liabilities	$ 49,658	$ 42,860

Debt Obligations - Schedule of

Debt Obligations - Schedule of Debt Obligations (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		12 Months Ended
		Jun. 30, 2018	Mar. 31, 2019		Dec. 31, 2018
Debt Instrument [Line Items]
Principal Borrowings Outstanding			$ 1,296,151		$ 1,240,389
Unamortized Debt Issuance Costs, Current			(291)		(295)
Unamortized Debt Issuance Costs, Long-term			(24,020)		(24,657)
Current portion of long-term debt			147,952		12,155
Long-term debt, net of current portion			1,123,888		1,203,282
Unused Borrowing Capacity			335,220		396,575
Solar Asset Backed Notes, Series 2018-1
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[1]		462,826		462,826
Unamortized Debt Issuance Costs, Current	[1]		(73)		(74)
Unamortized Debt Issuance Costs, Long-term	[1]		(8,988)		(9,172)
Current portion of long-term debt	[1]		3,657		3,655
Long-term debt, net of current portion	[1]		$ 450,108		$ 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			$ 186,784		$ 188,922
Unamortized Debt Issuance Costs, Current			(168)		(170)
Unamortized Debt Issuance Costs, Long-term			(4,524)		(4,614)
Current portion of long-term debt			6,679		6,679
Long-term debt, net of current portion			$ 175,413		$ 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]		$ 339,382		$ 342,833
Unamortized Debt Issuance Costs, Current	[2],[3]		(6)		(6)
Unamortized Debt Issuance Costs, Long-term	[2],[3]		(7,085)		(7,388)
Current portion of long-term debt	[2],[3]		294		294
Long-term debt, net of current portion	[2],[3]		$ 331,997		$ 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]
Forward Flow Loan Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[4]		$ 99,780		$ 58,425
Unamortized Debt Issuance Costs, Current	[4]		(42)		(43)
Unamortized Debt Issuance Costs, Long-term	[4]		(3,311)		(3,365)
Current portion of long-term debt	[4]		1,206		1,512
Long-term debt, net of current portion	[4]		95,221		53,505
Unused Borrowing Capacity	[4]		$ 30,220		$ 71,575
Interest Rate	[4]		4.90%		5.20%
Credit Agreement
Debt Instrument [Line Items]
Principal Borrowings Outstanding			$ 1,279		$ 1,283
Unamortized Debt Issuance Costs, Current			(2)		(2)
Unamortized Debt Issuance Costs, Long-term			(112)		(118)
Current portion of long-term debt			16		15
Long-term debt, net of current portion			$ 1,149		$ 1,148
Interest Rate			6.50%		6.50%
Maturity Date			Feb. 28, 2023		Feb. 28, 2023
Aggregation Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[5]		$ 70,000		$ 50,000
Long-term debt, net of current portion	[5]		70,000		50,000
Unused Borrowing Capacity	[5]		$ 305,000		$ 325,000
Interest Rate	[5]		5.70%		5.70%
Maturity Date	[5]		Sep. 30, 2020		Sep. 30, 2020
Working Capital Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[5],[6]		$ 136,100		$ 136,100
Current portion of long-term debt	[5],[6]		$ 136,100
Long-term debt, net of current portion	[5],[6]				$ 136,100
Interest Rate	[5],[6]		5.70%		5.60%
Maturity Date	[5],[6]		Mar. 31, 2020		Mar. 31, 2020
[1]	The interest rate disclosed in the table above is a weighted-average rate. The Series 2018-1 Notes are comprised 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 comprised 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 $325.2 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 October 31, 2019.
[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		3 Months Ended		12 Months Ended
		Aug. 31, 2018	Jun. 30, 2018	Mar. 31, 2019		Dec. 31, 2018
Debt Instrument [Line Items]
Principal borrowings outstanding				$ 1,296,151,000		$ 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]			$ 462,826,000		$ 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]			$ 339,382,000		$ 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				$ 325,200,000
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%
Forward Flow Loan Facility
Debt Instrument [Line Items]
Interest Rate	[4]			4.90%		5.20%
Debt instrument interest rate		1.50%
Principal borrowings outstanding	[4]			$ 99,780,000		$ 58,425,000
Debt instrument maturity period		20 years		20 years
Forward Flow Loan Facility | Maximum
Debt Instrument [Line Items]
Maturity Date				Oct. 31, 2019
[1]	The interest rate disclosed in the table above is a weighted-average rate. The Series 2018-1 Notes are comprised 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 comprised 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 $325.2 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 October 31, 2019.

Debt Obligations - Additional I

Debt Obligations - Additional Information (Details) - USD ($)		1 Months Ended		3 Months Ended		12 Months Ended
		Aug. 31, 2018	Jun. 30, 2018	Mar. 31, 2019		Dec. 31, 2018		Jan. 31, 2017	Mar. 31, 2015	Sep. 30, 2014
Debt Instrument [Line Items]
Principal Borrowings Outstanding				$ 1,296,151,000		$ 1,240,389,000
Restricted cash and cash equivalents				75,010,000		71,305,000
Letter of credit related to insurance contracts				13,900,000
Minimum
Debt Instrument [Line Items]
Restricted cash and cash equivalents				10,000,000		10,000,000
Solar Asset Backed Notes, Series 2018-1
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[1]			$ 462,826,000		$ 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				$ 13,600,000
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]			$ 339,382,000		$ 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				$ 325,200,000
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				$ 25,100,000
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%
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				$ 186,784,000		$ 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				$ 19,700,000
Forward Flow Loan Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[4]			$ 99,780,000		$ 58,425,000
Interest Rate	[4]			4.90%		5.20%
Debt instrument interest rate		1.50%
Maximum borrowing amount under credit agreement		$ 130,000,000
Debt instrument maturity period		20 years		20 years
Debt instrument offering date				Oct. 31, 2019
Debt Instrument interest rate description				Interest on each loan will accrue at an annual rate equal to the U.S. swap rate for the weighted-average life of such loan, plus an applicable margin equal to the greater of (a) 1.9% plus a spread adjustment based on the risk premium on the borrowing date relative to the market index-based risk premium on the closing date and (b) 1.5%. Scheduled principal payments are due on a quarterly basis, at the end of January, April, July and October of each year.
Forward Flow Loan Facility | Maximum
Debt Instrument [Line Items]
Revolving credit facility maturity date				Oct. 31, 2019
Forward Flow Loan Facility | Market Index-Based Risk Premium
Debt Instrument [Line Items]
Debt instrument interest rate		1.90%
Forward Flow Loan Facility | Required Reserves
Debt Instrument [Line Items]
Restricted cash and cash equivalents				$ 4,100,000
Aggregation Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[5]			$ 70,000,000		$ 50,000,000
Interest Rate	[5]			5.70%		5.70%
Revolving credit facility maturity date	[5]			Sep. 30, 2020		Sep. 30, 2020
Maximum borrowing amount under credit agreement										$ 375,000,000
Additional borrowing capacity										$ 175,000,000
Aggregation Facility | Minimum
Debt Instrument [Line Items]
Debt instrument interest rate				3.25%
Aggregation Facility | Maximum
Debt Instrument [Line Items]
Debt instrument interest rate				3.75%
Aggregation Facility | L I B O R Plus
Debt Instrument [Line Items]
Debt instrument interest rate				1.00%
Aggregation Facility | Federal Funds Rate Plus
Debt Instrument [Line Items]
Debt instrument interest rate				0.50%
Aggregation Facility | Required Reserves
Debt Instrument [Line Items]
Restricted cash and cash equivalents				$ 2,400,000
Working Capital Facility
Debt Instrument [Line Items]
Principal Borrowings Outstanding	[5],[6]			$ 136,100,000		$ 136,100,000
Interest Rate	[5],[6]			5.70%		5.60%
Revolving credit facility maturity date	[5],[6]			Mar. 31, 2020		Mar. 31, 2020
Debt instrument interest rate				2.25%
Maximum borrowing amount under credit agreement									$ 150,000,000
Debt Instrument interest rate description				(1) a rate equal to the Eurodollar Rate for the interest period divided by one minus the Eurodollar Reserve Percentage, plus a margin of 3.25%; or (2) the highest of (a) the Federal Funds Rate plus 0.50%, (b) the Citibank prime rate and (c) the one-month interest period Eurodollar rate plus 1.00%, plus a margin of 2.25%. Interest is payable depending on the type of borrowing at the end of (1) the interest period that the Company may elect as a term, not to exceed three months, (2) quarterly or (3) at maturity of the Working Capital Facility.
Letter of credit related to insurance contracts				$ 13,900,000
Minimum cash balance requirement				$ 30,000,000
Working Capital Facility | Federal Funds Rate Plus
Debt Instrument [Line Items]
Debt instrument interest rate				0.50%
Working Capital Facility | Eurodollar Reserve Percentage Plus
Debt Instrument [Line Items]
Debt instrument interest rate				3.25%
Working Capital Facility | Euro Dollar Rate Plus
Debt Instrument [Line Items]
Debt instrument interest rate				1.00%
[1]	The interest rate disclosed in the table above is a weighted-average rate. The Series 2018-1 Notes are comprised 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 comprised 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 $325.2 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 October 31, 2019.
[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.

Leases - Summary of Lease Costs

Leases - Summary of Lease Costs and Other Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Lease cost
Amortization of right-of-use assets	$ 294
Interest on lease liabilities	26
Operating lease cost	2,770
Short-term lease cost	722
Total lease cost	3,812
Finance leases:
Operating cash outflows from finance leases	26
Financing cash outflows from finance leases	271	$ 1,015
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 1,053	$ 199
Weighted-average remaining lease term - finance leases (in years)	2 years 10 months 24 days
Weighted-average discount rate - finance leases	7.80%
Operating leases:
Operating cash outflows from operating leases	$ 2,826
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 6,910
Weighted-average remaining lease term - operating leases (in years)	9 years 7 months 6 days
Weighted-average discount rate - operating leases	8.00%

Leases - Additional Information

Leases - Additional Information (Details)	3 Months Ended
	Mar. 31, 2019
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
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
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
Minimum | Fleet Vehicles Lease
Lessee Lease Description [Line Items]
Finance lease, agreement period	3 years
Minimum | Warehouse Lease Agreement
Lessee Lease Description [Line Items]
Operating lease, term of contract	1 year
Minimum | Equipment Lease Agreement
Lessee Lease Description [Line Items]
Operating lease, term of contract	3 years
Maximum | Fleet Vehicles Lease
Lessee Lease Description [Line Items]
Finance lease, agreement period	5 years
Maximum | Warehouse Lease Agreement
Lessee Lease Description [Line Items]
Operating lease, term of contract	7 years
Maximum | Equipment Lease Agreement
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	Mar. 31, 2019	Dec. 31, 2018
Finance Lease Liabilities Payments Due [Abstract]
2019	$ 727
2020	387
2021	336
2022	330
2023	52
Total minimum lease payments	1,832
Less: interest	189
Present value of finance lease obligations	1,643
Less: current portion	769	$ 1,921
Long-term portion	$ 874	$ 505

Leases - Schedule of Future M_2

Leases - Schedule of Future Minimum Lease Payments Under Non-cancellable Operating Leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Operating Lease Liabilities Payments Due [Abstract]
2019	$ 8,032
2020	9,483
2021	7,281
2022	5,595
2023	4,780
Thereafter	36,680
Total minimum lease payments	71,851
Less: present value impact	23,040
Present value of operating lease obligations	48,811
Less: current portion	6,992
Long-term portion	$ 41,819

Derivative Financial Instrume_3

Derivative Financial Instruments - Schedule of Derivative Financial Instruments at Fair Value (Details) - Interest Rate Swaps - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other Noncurrent Liabilities
Derivatives Fair Value [Line Items]
Fair Value, Derivatives designated as hedging instruments	$ 16,222	$ 9,884
Fair Value, Derivatives not designated as hedging instruments	2,529	1,262
Other Noncurrent Assets
Derivatives Fair Value [Line Items]
Fair Value, Derivatives not designated as hedging instruments	$ 13	$ 130

Derivative Financial Instrume_4

Derivative Financial Instruments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Amended Bank Of America Aggregation Credit Facility | Derivatives Not Designated as Hedging Instruments
Derivatives Fair Value [Line Items]
Notional amount	$ 40,000,000
Amended Bank Of America Aggregation Credit Facility | Interest Rate Swaps
Derivatives Fair Value [Line Items]
Percentage of outstanding term loans in interest rate hedged		75.00%
Threshold period	15 days
2018-2 Notes | Interest Rate Swaps
Derivatives Fair Value [Line Items]
Notional amount	$ 325,200,000
Accumulated other comprehensive income, expected amount of cash flow hedge to be reclassified to interest expense within the next 12 months	$ 1,800,000

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	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Total amounts presented in the income statement line items, Interest expense	$ 19,127	$ 16,922
Total losses (gains)	1,384	(2,262)
Total amounts presented in the income statement line items, Other (income) expense, net	1,385	(2,261)
Interest Expense, Net
Derivative Instruments, Gain (Loss) [Line Items]
Total losses (gains)	322	(381)
Other (Income) Expense, Net
Derivative Instruments, Gain (Loss) [Line Items]
Total losses (gains)	1,384	(2,262)
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	322	(381)
Derivatives Designated as Hedging Instruments | Cash Flow Hedging | Interest Rate Swaps | Other Comprehensive Income
Derivative Instruments, Gain (Loss) [Line Items]
Losses recognized in OCI	6,660	(5,143)
Derivatives Not Designated as Hedging Instruments | Interest Rate Swaps | Other (Income) Expense, Net
Derivative Instruments, Gain (Loss) [Line Items]
Losses (gains) recognized in income	$ 1,384	$ (2,262)

Investment Funds - Additional I

Investment Funds - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Investment Holdings [Line Items]
Summary of investment fund	As of March 31, 2019 and December 31, 2018, the Company had 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	$ 1,649,700,000	$ 1,565,300,000
Solar energy systems, net	1,590,888,000	1,938,874,000
Prepaid insurance balance	7,900,000	8,300,000
Distributions paid to reimburse fund investors	0
Accrued distribution	0
Restricted cash	75,010,000	71,305,000
Minimum
Investment Holdings [Line Items]
Restricted cash	10,000,000	10,000,000
Variable Interest Entities
Investment Holdings [Line Items]
Solar energy systems, net	1,448,012,000	1,752,271,000
Investment tax credit repayment	0
Restricted cash	4,071,000	2,443,000
Financing Obligation
Investment Holdings [Line Items]
Solar energy systems, net	45,200,000	55,800,000
Financing liabilities	5,300,000	$ 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		Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents		$ 213,474	$ 219,591
Accounts receivable, net		19,992	14,207
Prepaid expenses and other current assets		29,294	31,201
Total current assets		274,292	278,256
Restricted cash and cash equivalents		75,010	71,305
Solar energy systems, net		1,590,888	1,938,874
Other non-current assets, net		478,013	28,090
TOTAL ASSETS	[1]	2,428,383	2,327,255
Current liabilities:
Distributions payable to non-controlling interests and redeemable non-controlling interests		6,591	7,846
Current portion of long-term debt		147,952	12,155
Current portion of deferred revenue		26,246	30,199
Accrued and other current liabilities		49,658	42,860
Total current liabilities		291,274	166,430
Long-term debt, net of current portion		1,123,888	1,203,282
Deferred revenue, net of current portion		14,746	13,524
Other non-current liabilities		66,369	24,610
Total liabilities	[1]	1,960,307	1,845,471
Variable Interest Entities
Current assets:
Cash and cash equivalents		57,660	62,350
Accounts receivable, net		13,033	6,593
Prepaid expenses and other current assets		1,754	1,289
Total current assets		72,447	70,232
Restricted cash and cash equivalents		4,071	2,443
Solar energy systems, net		1,448,012	1,752,271
Other non-current assets, net		390,711	10,888
TOTAL ASSETS		1,915,241	1,835,834
Current liabilities:
Distributions payable to non-controlling interests and redeemable non-controlling interests		6,591	7,846
Current portion of long-term debt		1,206	1,512
Current portion of deferred revenue		2,411	2,320
Accrued and other current liabilities		5,194	4,860
Total current liabilities		15,402	16,538
Long-term debt, net of current portion		95,221	53,505
Deferred revenue, net of current portion		10,552	9,694
Other non-current liabilities		993	1,023
Total liabilities		$ 122,168	$ 80,760
[1]	The Company’s assets as of March 31, 2019 and December 31, 2018 include $1,915.2 million and $1,835.8 million consisting of assets of variable interest entities, or VIEs, that can only be used to settle obligations of the VIEs. These assets include solar energy systems, net, of $1,448.0 million and $1,752.3 million as of March 31, 2019 and December 31, 2018; other non-current assets, net of $390.7 million and $10.9 million as of March 31, 2019 and December 31, 2018; cash and cash equivalents of $57.7 million and $62.4 million as of March 31, 2019 and December 31, 2018; accounts receivable, net, of $13.0 million and $6.6 million as of March 31, 2019 and December 31, 2018; restricted cash and cash equivalents of $4.1 million and $2.4 million as of March 31, 2019 and December 31, 2018; and prepaid expenses and other current assets of $1.8 million and $1.3 million as of March 31, 2019 and December 31, 2018. The Company’s liabilities as of March 31, 2019 and December 31, 2018 included $122.2 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 $6.6 million and $7.8 million as of March 31, 2019 and December 31, 2018; deferred revenue of $13.0 million and $12.0 million as of March 31, 2019 and December 31, 2018; long-term debt of $96.4 million and $55.0 million as of March 31, 2019 and December 31, 2018; accrued and other current liabilities of $5.2 million and $4.9 million as of March 31, 2019 and December 31, 2018; and other non-current liabilities of $1.0 million and $1.0 million as of March 31, 2019 and December 31, 2018. For further information see Note 14—Investment Funds.

Redeemable Non-Controlling In_3

Redeemable Non-Controlling Interests and Equity - Schedule of Shares of Common Stock Reserved for Issuance (Details) - shares	Mar. 31, 2019	Dec. 31, 2018
Equity [Abstract]
Shares available for grant under equity incentive plans	15,346,000	13,323,000
Restricted stock units issued and outstanding	6,809,000	6,172,000
Stock options issued and outstanding	5,041,000	3,394,000
Long-term incentive plan	2,706,000	2,706,000
Total	29,902,000	25,595,000

Redeemable Non-Controlling In_4

Redeemable Non-Controlling Interests and Equity - Additional Information (Details) $ in Millions	Mar. 31, 2019USD ($)
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

Equity Compensation Plans - Add

Equity Compensation Plans - Additional Information (Details) - shares	1 Months Ended
	Jan. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under equity incentive plans		15,346,000	13,323,000
2014 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for grant under equity incentive plans		15,300,000
Number of additional shares available for issuance	4,800,000

Equity Compensation Plans - Sum

Equity Compensation Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 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	1,657,000
Shares Underlying Options, Exercised	(10,000)
Shares Underlying Options, Outstanding, Balance	5,041,000
Shares Underlying Options, Options vested and exercisable	1,815,000
Weighted-Average Exercise Price, Outstanding, Balance	$ 2.77
Weighted-Average Exercise Price, Granted	4.64
Weighted-Average Exercise Price, Exercised	3.69
Weighted-Average Exercise Price, Outstanding, Balance	3.38
Weighted-Average Exercise Price, Options vested and exercisable	$ 2.42
Weighted-Average Remaining Contractual Term, Outstanding, Balance	7 years 10 months 24 days
Weighted-Average Remaining Contractual Term, Options vested and exercisable	6 years
Aggregate Intrinsic Value	$ 8,889	$ 4,689
Aggregate Intrinsic Value, Options vested and exercisable	$ 5,226

Equity Compensation Plans - RSU

Equity Compensation Plans - RSU Activity (Details)	3 Months Ended
	Mar. 31, 2019$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Awards, Outstanding at December 31, 2018 | shares	6,172,000
Number of Awards, Granted | shares	1,206,000
Number of Awards, Vested | shares	(487,000)
Number of Awards, Forfeited | shares	(82,000)
Number of Awards, Outstanding at March 31, 2019 | shares	6,809,000
Weighted Average Grant Date Fair Value, Outstanding at December 31, 2018 | $ / shares	$ 3.84
Weighted Average Grant Date Fair Value, Granted | $ / shares	4.62
Weighted Average Grant Date Fair Value, Vested | $ / shares	3.85
Weighted Average Grant Date Fair Value, Forfeited | $ / shares	3.72
Weighted Average Grant Date Fair Value, Outstanding at March 31, 2019 | $ / shares	$ 3.98

Equity Compensation Plans - S_2

Equity Compensation Plans - Summary of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	$ 3,679	$ 2,969
Cost of Revenue
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	332	274
Sales and Marketing
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	735	831
General and Administrative
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	2,584	1,820
Research and Development
Schedule Of Stock Options [Line Items]
Stock-based compensation expense	$ 28	$ 44

Equity Compensation Plans - S_3

Equity Compensation Plans - Summary of Unrecognized Stock-Based Compensation Expense (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Schedule Of Stock Options [Line Items]
Unrecognized Stock-Based Compensation Expense	$ 23,808
RSUs
Schedule Of Stock Options [Line Items]
Unrecognized Stock-Based Compensation Expense, other than stock options	$ 17,646
Weighted- Average Period of Recognition	1 year 9 months 18 days
Stock Options
Schedule Of Stock Options [Line Items]
Unrecognized Stock-Based Compensation Expense, stock options	$ 6,162
Weighted- Average Period of Recognition	2 years 3 months 18 days

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Effective income tax rate	(44.50%)	(43.60%)

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		12 Months Ended
	Aug. 31, 2017	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Related Party Transaction [Line Items]
Sales and marketing		$ 29,634	$ 11,125
Accounts payable—related party		100		$ 200
Accrued equity distributions		6,591		7,846
Related Party
Related Party Transaction [Line Items]
Sales and marketing		800	700
Amounts due from direct-sales personnel		4,000		5,200
Provision for advances to direct-sales personnel		1,000		1,000
Accrued equity distributions		1,100		$ 1,500
Vivint Services
Related Party Transaction [Line Items]
Initial term of agreement period	2 years
Fees incurred in conjunction with agreements entered		$ 2,400	$ 1,000

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended
	Apr. 30, 2018	Sep. 30, 2016	Mar. 31, 2019
Other Commitments [Line Items]
Standby letter of credit outstanding			$ 13.9
Total estimated obligation earned over deferment period			$ 16.2
Sun Edison Inc
Other Commitments [Line Items]
Unsecured claim initial amount		$ 1,000
Claim amount received from other party	$ 590
Received initial distribution amount	$ 2.1

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	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator:
Net loss attributable to common stockholders	$ (26,242)	$ (12,976)
Denominator:
Shares used in computing net loss attributable per share to common stockholders, basic	120,307	115,155
Shares used in computing net loss attributable per share to common stockholders, diluted	120,307	115,155
Net loss per share attributable to common stockholders:
Basic and diluted	$ (0.22)	$ (0.11)