SolarCity 10-K 24 Feb 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Jan. 31, 2015	Jun. 30, 2014
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	SCTY
Entity Registrant Name	SOLARCITY CORP
Entity Central Index Key	1408356
Current Fiscal Year End Date	-19
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		0
Entity Public Float			$0

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$504,383		$577,080
Short-term investments	138,311		0
Restricted cash	20,875		19,182
Accounts receivable (net of allowances for doubtful accounts of $1,941 and $955 as of December 31, 2014 and December 31, 2013, respectively)	22,708		23,011
Rebates receivable - net	30,021		20,131
Inventories	217,223		111,394
Deferred income tax asset	13,149		9,845
Prepaid expenses and other current assets	55,729		27,020
Total current assets	1,002,399		787,663
Solar energy systems, leased and to be leased - net	2,796,796		1,682,521
Property, plant and equipment - net	101,914		22,407
Goodwill and intangible assets - net	539,557		278,169
Customer notes receivable, net of current portion	34,544		0
Other assets	111,001		38,774
Total assets	4,586,211	[1]	2,809,534	[1]
Current liabilities:
Accounts payable	237,809		121,556
Distributions payable to noncontrolling interests and redeemable noncontrolling interests	8,552		20,390
Current portion of deferred U.S. Treasury grant income	15,330		15,340
Accrued and other current liabilities	152,408		72,157
Customer deposits	10,560		8,828
Current portion of deferred revenue	86,238		59,899
Current portion of long-term debt	12,931		7,422
Current portion of solar asset-backed notes	13,574		3,155
Current portion of lease pass-through financing obligation	29,241		29,041
Current portion of sale-leaseback financing obligation	448		418
Total current liabilities	567,091		338,206
Deferred revenue, net of current portion	557,408		410,161
Long-term debt, net of current portion	290,414		238,612
Convertible senior notes	796,000		230,000
Solar asset-backed notes, net of current portion	304,393		49,780
Long-term deferred tax liability	13,194		9,238
Lease pass-through financing obligation, net of current portion	59,490		64,167
Sale-leaseback financing obligation, net of current portion	13,889		14,338
Deferred U.S. Treasury grant income, net of current portion	397,486		412,469
Other liabilities and deferred credits	244,474		193,439
Total liabilities	3,243,839	[1]	1,960,410	[1]
Commitments and contingencies (Note 22)
Redeemable noncontrolling interests in subsidiaries	186,788		44,709
Stockholders' equity:
Common stock, $0.0001 par value - authorized, 1,000,000 shares as of December 31, 2014 and December 31, 2013; issued and outstanding, 96,521 and 91,009 shares as of December 31, 2014 and December 31, 2013, respectively	10		10
Additional paid-in capital	1,003,992		819,914
Accumulated deficit	-258,360		-202,326
Total stockholders' equity	745,642		617,598
Noncontrolling interests in subsidiaries	409,942		186,817
Total equity	1,155,584		804,415
Total liabilities and equity	$4,586,211		$2,809,534
[1]	(1) SolarCity Corporation’s, or the Company’s, consolidated assets as of December 31, 2014 and 2013 include $1,672,370 and $823,165, respectively, being assets of variable interest entities, or VIEs, that can only be used to settle obligations of the VIEs. These assets include solar energy systems, leased and to be leased - net of $1,581,459 and $759,148 as of December 31, 2014 and 2013, respectively; property, plant and equipment - net of $24,286 and $0 as of December 31, 2014 and 2013, respectively; cash and cash equivalents of $27,820 and $35,141 as of December 31, 2014 and 2013, respectively; inventory of $614 and $0 as of December 31, 2014 and 2013, respectively; restricted cash, short-term, of $106 and $115 as of December 31, 2014 and 2013, respectively; accounts receivable - net of $6,769 and $4,802 as of December 31, 2014 and 2013, respectively; prepaid expenses and other current assets of $1,839 and $3,831 as of December 31, 2014 and 2013, respectively; rebates receivable of $25,397 and $17,351 as of December 31, 2014 and 2013, respectively; restricted cash long-term, of $300 and $0 as of December 31, 2014 and 2013,respectively; and other assets of $3,780 and $2,777 as of December 31, 2014 and 2013, respectively. The Company’s consolidated liabilities as of December 31, 2014 and 2013 included $27,808 and $19,853, respectively, being liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include distributions payable to noncontrolling interests and redeemable noncontrolling interests of $8,552 and $20,390 as of December 31, 2014 and 2013, respectively; customer deposits of $6,405 and $5,291 as of December 31, 2014 and 2013, respectively; accounts payable of $2,748 and $0 as of December 31, 2014 and 2013, respectively; accrued and other payables of $969 and $615 as of December 31, 2014 and 2013, respectively; and bank borrowings of $9,134 and $5,733 as of December 31, 2014 and 2013, respectively.

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Allowances for doubtful accounts	$1,941		$955
Common stock, par value	$0.00		$0.00
Common stock, shares authorized	1,000,000,000		1,000,000,000
Common stock, shares issued	96,521,000		96,521,000
Common stock, shares outstanding	91,009,000		91,009,000
Total assets	4,586,211	[1]	2,809,534	[1]
Solar energy systems, leased and to be leased - net	2,796,796		1,682,521
Property, plant and equipment - net	101,914		22,407
Cash and cash equivalents	504,383		577,080
Inventories	217,223		111,394
Accounts receivable (net of allowances for doubtful accounts of $1,941 and $955 as of December 31, 2014 and December 31, 2013, respectively)	22,708		23,011
Prepaid expenses and other current assets	55,729		27,020
Rebates receivable	30,021		20,131
Other assets	111,001		38,774
Distributions payable to noncontrolling interests and redeemable noncontrolling interests	8,552		20,390
Accounts payable	237,809		121,556
Customer deposits	10,560		8,828
VIEs [Member]
Total assets	1,672,370	[1]	823,165	[1]
Solar energy systems, leased and to be leased - net	1,581,459		759,148
Property, plant and equipment - net	24,286		0
Cash and cash equivalents	27,820		35,141
Inventories	614		0
Restricted cash, current	106		115
Accounts receivable (net of allowances for doubtful accounts of $1,941 and $955 as of December 31, 2014 and December 31, 2013, respectively)	6,769		4,802
Prepaid expenses and other current assets	1,839		3,831
Rebates receivable	25,397		17,351
Restricted cash, noncurrent	300		0
Other assets	3,780		2,777
Non recourse Variable Interest Entity's (VIE) liabilities	27,808	[1]	19,853	[1]
Distributions payable to noncontrolling interests and redeemable noncontrolling interests	8,552		20,390
Accounts payable	2,748		0
Customer deposits	6,405		5,291
Accrued liabilities and other payables	969		615
Bank borrowings	$9,134		$5,733
[1]	(1) SolarCity Corporation’s, or the Company’s, consolidated assets as of December 31, 2014 and 2013 include $1,672,370 and $823,165, respectively, being assets of variable interest entities, or VIEs, that can only be used to settle obligations of the VIEs. These assets include solar energy systems, leased and to be leased - net of $1,581,459 and $759,148 as of December 31, 2014 and 2013, respectively; property, plant and equipment - net of $24,286 and $0 as of December 31, 2014 and 2013, respectively; cash and cash equivalents of $27,820 and $35,141 as of December 31, 2014 and 2013, respectively; inventory of $614 and $0 as of December 31, 2014 and 2013, respectively; restricted cash, short-term, of $106 and $115 as of December 31, 2014 and 2013, respectively; accounts receivable - net of $6,769 and $4,802 as of December 31, 2014 and 2013, respectively; prepaid expenses and other current assets of $1,839 and $3,831 as of December 31, 2014 and 2013, respectively; rebates receivable of $25,397 and $17,351 as of December 31, 2014 and 2013, respectively; restricted cash long-term, of $300 and $0 as of December 31, 2014 and 2013,respectively; and other assets of $3,780 and $2,777 as of December 31, 2014 and 2013, respectively. The Company’s consolidated liabilities as of December 31, 2014 and 2013 included $27,808 and $19,853, respectively, being liabilities of VIEs whose creditors have no recourse to the Company. These liabilities include distributions payable to noncontrolling interests and redeemable noncontrolling interests of $8,552 and $20,390 as of December 31, 2014 and 2013, respectively; customer deposits of $6,405 and $5,291 as of December 31, 2014 and 2013, respectively; accounts payable of $2,748 and $0 as of December 31, 2014 and 2013, respectively; accrued and other payables of $969 and $615 as of December 31, 2014 and 2013, respectively; and bank borrowings of $9,134 and $5,733 as of December 31, 2014 and 2013, respectively.

Consolidated_Statements_of_Ope

Consolidated Statements of Operations (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue:
Operating leases and solar energy systems incentives	$173,636	$82,856	$46,098
Solar energy systems and components sales	81,395	80,981	80,810
Total revenue	255,031	163,837	126,908
Cost of revenue:
Operating leases and solar energy systems incentives	92,920	32,745	14,596
Solar energy systems and components sales	83,512	91,723	84,856
Total cost of revenue	176,432	124,468	99,452
Gross profit	78,599	39,369	27,456
Operating expenses:
Sales and marketing	238,608	97,426	69,392
General and administrative	156,426	89,801	49,075
Research and development	19,162	1,520
Total operating expenses	414,196	188,747	118,467
Loss from operations	-335,597	-149,378	-91,011
Interest expense - net	55,758	25,738	20,142
Other expense - net	10,611	1,441	2,519
Loss before income taxes	-401,966	-176,557	-113,672
Income tax benefit (provision)	26,736	24,799	-54
Net loss	-375,230	-151,758	-113,726
Net loss attributable to noncontrolling interests and redeemable noncontrolling interests	-319,196	-95,968	-14,391
Net loss attributable to stockholders	-56,034	-55,790	-99,335
Net loss attributable to common stockholders
Basic	-56,034	-55,790	-109,426
Diluted	($56,034)	($55,790)	($109,703)
Net loss per share attributable to common stockholders
Basic	($0.60)	($0.70)	($7.68)
Diluted	($0.60)	($0.70)	($7.69)
Weighted average shares used to compute net loss per share attributable to common stockholders
Basic	93,333,880	79,781,976	14,240,187
Diluted	93,333,880	79,781,976	14,267,767

Consolidated_Statements_of_Con

Consolidated Statements of Convertible Redeemable Preferred Stock and Equity (USD $)	Total	Paramount Energy Solutions Llc	Zep Solar [Member]	Silevo, Inc [Member]	Conversion of preferred stock to common stock [Member]	Preferred stock warrants to common stock warrants [Member]	Convertible redeemable preferred stock [Member]	Convertible redeemable preferred stock [Member]	Convertible redeemable preferred stock [Member]	Convertible redeemable preferred stock [Member]	Convertible redeemable preferred stock [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Total Stockholders' Equity (Deficit) [Member]	Total Stockholders' Equity (Deficit) [Member]	Total Stockholders' Equity (Deficit) [Member]	Total Stockholders' Equity (Deficit) [Member]	Total Stockholders' Equity (Deficit) [Member]	Total Stockholders' Equity (Deficit) [Member]	Noncontrolling Interests in Subsidiaries [Member]
In Thousands, except Share data	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	USD ($)	Series C convertible redeemable preferred stock [Member]	Series F convertible redeemable preferred stock [Member]	Series G convertible redeemable preferred stock [Member]	Conversion of preferred stock to common stock [Member]	USD ($)	Paramount Energy Solutions Llc	Zep Solar [Member]	Silevo, Inc [Member]	Conversion of preferred stock to common stock [Member]	Preferred stock warrants to common stock warrants [Member]	USD ($)	Paramount Energy Solutions Llc	Zep Solar [Member]	Silevo, Inc [Member]	Conversion of preferred stock to common stock [Member]	Preferred stock warrants to common stock warrants [Member]	USD ($)	USD ($)	Paramount Energy Solutions Llc	Zep Solar [Member]	Silevo, Inc [Member]	Conversion of preferred stock to common stock [Member]	Preferred stock warrants to common stock warrants [Member]	USD ($)
								USD ($)	USD ($)	USD ($)	USD ($)		USD ($)	USD ($)			USD ($)		USD ($)	USD ($)	USD ($)	USD ($)	USD ($)			USD ($)	USD ($)	USD ($)	USD ($)	USD ($)
Beginning balance at Dec. 31, 2011	$62,676											$1						$9,538						($47,201)	($37,662)						$100,338
Beginning balance, convertible redeemable preferred stock at Dec. 31, 2011							125,722
Beginning balance, convertible redeemable preferred stock, shares at Dec. 31, 2011							41,893,000
Beginning balance, shares at Dec. 31, 2011												10,465,000
Issuance of convertible redeemable preferred stock upon exercise of warrants, shares								113,000	8,000
Issuance of convertible redeemable preferred stock upon exercise of warrants								1,480	150
Issuance of convertible redeemable preferred stock, net of issuance cost, shares										3,387,000
Issuance of convertible redeemable preferred stock, net of issuance cost	92,386									81,218								92,385							92,386
Conversion of stock, shares											-45,401,000					50,386,000
Conversion of stock					208,570	5,821					-208,570						5					208,565	5,821						208,570	5,821
Issuance of common stock upon exercise of Issuance of common stock upon exercise of stock options for cash, shares	902,000											902,000
Issuance of common stock upon exercise of stock options for cash	1,724																	1,724							1,724
Issuance of common stock from public offering, shares												13,160,000
Issuance of common stock from public offering, net of underwriters discount and commissions and issuance cost												1
Contributions from noncontrolling interests	115,133																														115,133
Stock-based compensation expense	11,179																	11,179							11,179
Net loss	-122,422																							-99,335	-99,335						-23,087
Distributions to noncontrolling interests	-95,591																														-95,591
Acquisition of noncontrolling interest in subsidiaries	918																	918							918
Ending balance at Dec. 31, 2012	280,394											7						330,130						-146,536	183,601						96,793
Ending balance, shares at Dec. 31, 2012												74,913,000
Issuance of common stock upon exercise of Issuance of common stock upon exercise of stock options for cash, shares	4,260,000											4,260,000
Issuance of common stock upon exercise of stock options for cash	15,545																	15,545							15,545
Issuance of common stock from public offering, shares												3,910,000
Issuance of common stock from public offering, net of underwriters discount and commissions and issuance cost	174,083											1						174,082							174,083
Issuance of common stock upon business acquisitions, shares													3,675,000	2,752,000
Stock Options Issued During Period Value Acquisitions		108,734	14,893										1	1					108,733	14,893						108,734	14,893
Issuance of common stock upon vesting of restricted stock units, shares												14,000
Issuance of common stock upon exercise of stock warrants for cash, shares												1,485,000
Contributions from noncontrolling interests	189,779																														189,779
Stock-based compensation expense	27,936																	27,936							27,936
Net loss	-32,904																							-55,790	-55,790						22,886
Distributions to noncontrolling interests	-122,641																														-122,641
Issuance of common stock upon business acquisitions, net of issuance costs			140,562																	140,561							140,562
Issuance of common stock upon exercise of stock warrants for cash	8,034																	8,034							8,034
Ending balance at Dec. 31, 2013	804,415											10						819,914						-202,326	617,598						186,817
Ending balance, shares at Dec. 31, 2013	91,009,000											91,009,000
Conversion of stock, shares	8,372,065
Issuance of common stock upon exercise of Issuance of common stock upon exercise of stock options for cash, shares	3,176,000											3,176,000
Issuance of common stock upon business acquisitions, shares															2,284,000
Stock Options Issued During Period Value Acquisitions				137,958																	137,958							137,958
Issuance of common stock upon vesting of restricted stock units, shares												52,000
Contributions from noncontrolling interests	517,471																														517,471
Stock-based compensation expense	88,936																	88,936							88,936
Net loss	-234,158																							-56,034	-56,034						-178,124
Distributions to noncontrolling interests	-90,974																														-90,974
Acquisition of noncontrolling interest in subsidiaries	2,000																	2,000							2,000
Issuance of common stock upon exercise of stock warrants for cash	20,255																	20,255							20,255
Issuance of restricted stock units upon acquisition				132																	132							132
Purchase of capped call options	-65,203																	-65,203							-65,203
Transfers to redeemable noncontrolling interests in subsidiaries	-25,248																														-25,248
Ending balance at Dec. 31, 2014	$1,155,584											$10						$1,003,992						($258,360)	$745,642						$409,942
Ending balance, shares at Dec. 31, 2014	91,009,000											96,521,000

Consolidated_Statements_of_Con1

Consolidated Statements of Convertible Redeemable Preferred Stock and Equity (Parenthetical) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Issuance of common stock from public offering, underwriters discount and commissions and issuance cost	$7,888	$12,895
Series G convertible redeemable preferred stock [Member]
Issuance of convertible redeemable preferred stock, price per share		$23.92
Issuance of convertible redeemable preferred stock, issuance cost		132
Paramount Energy Solutions Llc
Issuance of common stock upon business acquisitions, issuance costs	$70

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating activities:
Net loss	($375,230)	($151,758)	($113,726)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Loss on disposal of property, plant and equipment and construction in progress	1,404	60	17
Depreciation and amortization net of amortization of deferred U.S. Treasury grant income	97,880	41,448	20,809
Non cash interest and other expense	13,631	13,438	12,001
Stock-based compensation, net of amounts capitalized	65,562	21,262	8,677
Revaluation of convertible redeemable preferred stock warrants	0	0	1,898
Revaluation of preferred stock forward contract	0	0	350
Loss on extinguishment of long-term debt	4,533	306	0
Deferred income taxes	-26,680	-25,424	13
Reduction in lease pass-through financing obligation	-48,837	-35,675	-16,159
Changes in operating assets and liabilities:
Restricted cash	-17,699	-13,059	-864
Accounts receivable	945	2,911	-13,978
Rebates receivable	-9,890	-2,630	-3,817
Inventories	-97,347	-19,954	55,734
Prepaid expenses and other current assets	-23,579	-19,276	7,914
Other assets	-32,019	-6,882	-4,939
Accounts payable	112,480	50,750	-99,600
Accrued and other liabilities	-22,676	84,444	70,133
Customer deposits	1,732	919	-6,024
Deferred revenue	137,941	233,635	121,355
Net cash (used in) provided by operating activities	-217,849	174,515	39,794
Investing activities:
Payments for the cost of solar energy systems, leased and to be leased	-1,162,963	-716,947	-420,153
Purchase of property, plant and equipment	-22,892	-9,126	-8,367
Investment in promissory notes receivable and other investments	-21,750	0	0
Purchases of short-term investments	-167,397	0	0
Proceeds from sales and maturities of short-term investments	28,764	0	0
Acquisition of business, net of cash acquired	1,874	-3,826	0
Payments to acquire redeemable noncontrolling interest in a subsidiary	-450	0	0
Net cash used in investing activities	-1,344,814	-729,899	-428,520
Financing activities:
Borrowings under long-term debt	373,453	203,228	152,804
Repayments of long-term debt	-336,557	-65,328	-77,299
Proceeds from issuance of solar asset-backed notes	262,880	51,334	0
Repayments of borrowings under solar asset-backed notes	-5,932	-1,461	0
Payment of deferred purchase consideration	-2,206	-3,382	0
Repayments of sale-leaseback financing obligation	-419	-388	-361
Proceeds from lease pass-through financing obligation	44,563	57,780	145,846
Repayments of lease pass-through financing obligation	-12,041	-41,148	0
Repayment of capital lease obligations	-2,772	-1,594	-28,442
Proceeds from investment by noncontrolling interests and redeemable noncontrolling interests in subsidiaries	777,963	362,692	161,426
Distributions paid to noncontrolling interests and redeemable noncontrolling interests in subsidiaries	-117,125	-137,005	-144,493
Proceeds from U.S. Treasury grants	342	127,476	113,648
Net cash provided by financing activities before equity and convertible notes issuances	982,149	552,204	323,129
Equity and convertible notes issuances:
Proceeds from issuance of common stock	0	174,083	92,386
Proceeds from issuance of convertible senior notes	552,765	222,518	0
Purchase of capped call options	-65,203	0	0
Proceeds from exercise of stock options	20,255	15,545	1,724
Proceeds from exercise of common stock warrants	0	8,034	0
Proceeds from exercise of convertible redeemable preferred stock warrants	0	0	228
Proceeds from issuance of convertible redeemable preferred stock	0	0	80,868
Net cash provided by equity and convertible notes issuances	507,817	420,180	175,206
Net cash provided by financing activities	1,489,966	972,384	498,335
Net (decrease) increase in cash and cash equivalents	-72,697	417,000	109,609
Cash and cash equivalents, beginning of period	577,080	160,080	50,471
Cash and cash equivalents, end of period	504,383	577,080	160,080
Supplemental disclosures of cash flow information:
Cash paid during the period for interest	22,702	6,603	6,710
Cash paid (received) during the period for taxes	1,881	-1,726	2,689
Noncash investing and financing activities
Conversion of convertible redeemable preferred stock upon initial public offering of common stock	0	0	208,570
Conversion of convertible redeemable preferred stock warrants to common stock warrants upon initial public offering of common stock	$0	$0	$5,821

Organization

Organization	12 Months Ended
	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	1. Organization
	SolarCity Corporation, or the Company, was incorporated as a Delaware corporation on June 21, 2006. The Company is engaged in the design, manufacture, installation and sale or lease of solar energy systems to residential and commercial customers, or sale of electricity generated by solar energy systems to customers. The Company’s headquarters are located in San Mateo, California.

Summary_of_Significant_Account

Summary of Significant Accounting Policies and Procedures	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Procedures	2. Summary of Significant Accounting Policies and Procedures
	Basis of Presentation and Principles of Consolidation
	The accompanying consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles, or GAAP, and reflect the accounts and operations of the Company and those of its subsidiaries in which the Company has a controlling financial interest. In accordance with the provisions of Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, 810, Consolidation, the Company consolidates any variable interest entity, or VIE, of which it is the primary beneficiary. The typical condition for a controlling financial interest ownership is holding a majority of the voting interests of an entity; however, a controlling financial interest may also exist in entities, such as VIEs, through arrangements that do not involve controlling voting interests. ASC 810 requires a variable interest holder to consolidate a VIE if that party has the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. The Company does not consolidate a VIE in which it has a majority ownership interest when the Company is not considered the primary beneficiary. The Company has determined that it is the primary beneficiary of a number of VIEs (see Note 3, Acquisitions, and Note 12, VIE Fund Arrangements). The Company evaluates its relationships with all 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.
	The Company and its subsidiaries’ fiscal quarters and years are the same as calendar quarters and years except for one acquired subsidiary, Silevo, Inc., or Silevo, which continues to have fiscal quarters based on 13-week periods and fiscal years based on 52-week periods. For 2014, Silevo’s fiscal year ended on December 27, 2014, and it did not have any material activity between that date and December 31, 2014.
	Reclassifications
	Prior period research and development expenses were reclassified from general and administrative expense and disclosed separately as research and development expense in the consolidated financial statements and accompanying notes in order to provide comparability to current period balances. The reclassifications did not impact prior period results of operations, cash flows, total assets, total liabilities or total equity.
	Use of Estimates
	The preparation of the consolidated financial statements requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Management regularly makes significant estimates and assumptions regarding the selling price of undelivered elements for revenue recognition purposes, the collectability of accounts and rebates receivable, the valuation of inventories, the labor costs for long-term contracts used as a basis for determining the percentage of completion for such contracts, the fair values and residual values of solar energy systems subject to leases, the accounting for business combinations, the fair values and useful lives of acquired tangible and intangible assets, the fair value of debt assumed under business combinations, the fair value of contingent consideration payable under business combinations, the fair value of short-term investments, the useful lives of solar energy systems, property, plant and equipment, the determination of accrued warranty, the determination of accrued performance guarantee, the determination of lease pass-through financing obligations, the discount rates used to determine the fair values of investment tax credits, the valuation of stock-based compensation, the determination of valuation allowances associated with deferred tax assets, asset impairment and other items. Management bases its estimates on historical experience and on various other assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ materially from those estimates.
	Cash and Cash Equivalents
	The Company considers all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents. The Company maintains cash and cash equivalents, which consist principally of demand deposits with high-credit-quality financial institutions. The Company has exposure to credit risk to the extent cash and cash equivalent balances, including any restricted cash balances on deposit, exceed amounts covered by federal deposit insurance. The Company believes that its credit risk is not significant.
	Short-Term Investments
	The Company’s short-term investments comprise of corporate debt securities and asset-backed securities. The Company classifies short-term investments as available-for-sale and carries them at fair value, with any unrealized gains or losses recognized as other comprehensive income or loss in the consolidated balance sheet. The specific identification method is used to determine the cost of any securities disposed of, with any realized gains or losses recognized as other income or expense in the consolidated statement of operations. Short-term investments are anticipated to be used for current operations and are, therefore, classified as current assets even though their maturities may extend beyond one year. The Company periodically reviews short-term investments for impairment. In the event a decline in value is determined to be other-than-temporary, an impairment loss is recognized. When determining if a decline in value is other-than-temporary, the Company takes into consideration the current market conditions and the duration and severity of and the reason for the decline, as well as the likelihood that it would need to sell the security prior to a recovery of par value.
	The Company did not have any short-term investments as of December 31, 2013. As of December 31, 2014, short-term investments were comprised of $126.2 million of corporate debt securities and $12.1 million of asset-backed securities. The costs of these securities approximated their fair values, and there were no material gross realized or unrealized gains, gross realized or unrealized losses or impairment losses recognized for the year ended December 31, 2014. As of December 31, 2014, all short-term investments were scheduled to mature within the next twelve months.
	Restricted Cash
	Restricted cash includes cash received from certain fund investors that had not been released for use by the Company, cash held to service certain payments under various securitization transactions including management expenses and principal and interest payments to solar asset-backed note holders and balances collateralizing outstanding letters of credit, outstanding credit card borrowing facilities and obligations under certain operating leases.
	Accounts Receivable
	Accounts receivable primarily represent trade receivables from sales to residential and commercial customers recorded at net realizable value. The Company maintains an allowance for doubtful accounts to reserve for potentially uncollectible accounts receivable. The Company reviews its accounts receivable by aging category to identify significant customer balances with known disputes or collection issues. In determining the allowance, the Company makes judgments about the creditworthiness of a majority of its customers based on ongoing credit evaluations. The Company also considers its historical level of credit losses and current economic trends that might impact the level of future credit losses. The Company writes off accounts receivable when they are deemed uncollectible.
	Customer Notes Receivable
	In the fourth quarter of 2014, the Company launched MyPower, a program that offers residential customers the option to finance the purchase of solar energy systems through a 30-year loan provided by a wholly owned subsidiary of the Company. In order to qualify for a loan, a customer must pass the Company’s credit evaluation process, and the loans are secured by the solar energy systems financed. The outstanding loan balances, net of any allowance for potentially uncollectible amounts, are presented on the consolidated balance sheets as a component of prepaid expenses and other current assets for the current portion and as customer notes receivable, net of current portion, for the long-term portion. In determining the allowance and credit quality, the Company identifies significant customers with known disputes or collection issues and considers its historical level of credit losses and current economic trends that might impact the level of future credit losses. Customer notes receivable that are individually impaired are charged-off as a write-off of allowance for losses. As of December 31, 2014, there were no significant customers with known disputes or collection issues, and the amount of potentially uncollectible amounts was also insignificant. Accordingly, the Company did not establish an allowance for losses against customer notes receivable. In addition, there were no non-accrual or past due customer notes receivable as of December 31, 2014.
	Rebates Receivable
	Rebates receivable represent rebates due from utility companies and government agencies. These receivables include rebates that have been assigned to the Company by its cash customers on state-approved solar energy system installations sold to the customers and also uncollected incentives from state and local government agencies for solar energy system installations that have been leased to customers or are used to generate and sell electricity to customers under power purchase agreements. For the rebates assigned to the Company by its customers, the Company assumes the responsibility for the application and collection of the rebate. The processing cycle for these rebates and incentives involves a multi-step process in which the Company accumulates and submits information required by the utility company or state agency necessary for the collection of the rebate. The entire process typically can take up to several months to complete. The Company recognizes rebates receivable upon the solar energy system passing inspection by the utility or authority having jurisdiction after completion of system installation. The Company maintains an allowance to reserve for potentially uncollectible rebates. In determining the allowance, the Company makes judgments based on the length of period that a rebate amount has been outstanding and reasons for the delays in collecting the rebate.
	Concentrations of Risk
	Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments, accounts receivable and rebates receivable. The associated risk of concentration for cash and cash equivalents is mitigated by banking with creditworthy institutions. At certain times, amounts on deposit exceed federal deposit insurance limits. The associated risk of concentration for short-term investments is mitigated by holding a diversified portfolio of highly rated short-term investments. The Company does not require collateral or other security to support accounts receivable. To reduce credit risk, management performs periodic credit evaluations and ongoing evaluations of its customers’ financial condition. Rebates receivable are due from various states and local governments as well as various utility companies. The Company maintains reserves for any amounts that it considers to be uncollectable.
	Fair Value of Financial Instruments
	ASC 820, Fair Value Measurements, clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability.
	ASC 820 requires that the valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. ASC 820 establishes a three-tier fair value hierarchy, which prioritizes inputs that may be used to measure fair value as follows:
	—	Level 1—Observable inputs that reflect quoted prices for identical assets or liabilities in active markets.
	—	Level 2—Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	—	Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	As of December 31, 2013, there were no fair value measurements of assets or liabilities subsequent to initial recognition. As of December 31, 2014, the assets and liabilities carried at fair value on a recurring basis included cash equivalents, short-term investments and contingent consideration (see Note 3, Acquisitions). As of December 31, 2014, the fair value of the Company’s cash equivalents, short-term investments and contingent consideration were as follows (in thousands):
		Level 1				Level 2				Level 3
	Cash equivalents:
	Money market funds	$	54,229			$	—			$	—
	Corporate debt securities	$	—			$	7,599			$	—
	Short-term investments:
	Corporate debt securities	$	—			$	126,159			$	—
	Asset-backed securities	$	—			$	12,152			$	—
	Liabilities:
	Contingent consideration	$	—			$	—			$	117,197
	The Company classified its money market funds within Level 1 because their fair values are based on their quoted market prices. The Company classified its corporate debt securities and asset-backed securities within Level 2 because their fair values are determined using alternative pricing sources and models that utilized market observable inputs to determine their fair values. The Company classified its contingent consideration within Level 3 because their fair values are determined using unobservable probability estimates and an unobservable estimated discount rate applicable to the acquisition to determine the fair value. Furthermore, during the year ended December 31, 2014, there were no transfers between the levels of the fair value hierarchy.
	The contingent consideration is dependent on the achievement of specified production milestones for the acquired business as discussed in Note 3, Acquisitions. The fair value of the contingent consideration is directly proportional to the estimated probabilities of achievement of these milestones. As of December 31, 2014, the estimated probabilities ranged from 90% to 95%, the estimated discount rates ranged from 5.0% to 7.0%, $42.0 million was included under accrued and other current liabilities on the consolidated balance sheets and $75.2 million was included under other liabilities and deferred credits on the consolidated balance sheets. The following table summarizes the activity of the Level 3 contingent consideration balance in the year ended December 31, 2014 (in thousands):
	Balance - beginning of the period		$	—
	Acquisition of Silevo			115,319
	Change in fair value recorded in other income (expense) - net			1,878
	Balance - end of the period		$	117,197
	The Company’s financial instruments that are not re-measured at fair value include accounts receivable, customer notes receivable, rebates receivable, accounts payable, customer deposits, distributions payable to noncontrolling interests and redeemable noncontrolling interests, participation interest, solar asset-backed notes, convertible senior notes, Solar Bonds and long-term debt. The carrying values of these financial instruments other than the participation interest, solar asset-backed notes, convertible senior notes, Solar Bonds and long-term debt approximate their fair values due to the fact that they were short-term in nature at December 31, 2014 and 2013 (Level 1). The fair value of convertible senior notes was $752.2 million and $273.0 million as of December 31, 2014 and 2013, respectively, based on their last actively traded prices (Level 1). The Company estimates the fair value of customer notes receivable, solar asset-backed notes, Solar Bonds and long-term debt based on rates currently offered for debt with similar maturities and terms (Level 3). The Company has estimated the fair value of customer notes receivable, Solar Bonds and long-term debt to approximate their carrying values. The Company has estimated the fair value of solar asset-backed notes to be $328.3 million and $52.9 million as of December 31, 2014 and 2013, respectively. The Company has estimated the fair value of the participation interest to be $14.1 million and $15.1 million as of December 31, 2014 and 2013, respectively, based on rates currently offered for instruments with similar maturities and terms (Level 3).
	Business Combinations
	The Company accounts for business acquisitions under ASC 805, Business Combinations. The cost of an acquisition is measured at the fair value of the assets given, equity instruments issued and liabilities assumed at the acquisition date. Costs that are directly attributable to the acquisition are expensed as incurred. Identifiable assets, including intangible assets, acquired and liabilities, including contingent liabilities, assumed in the acquisition are measured initially at their fair values at the acquisition date. Any noncontrolling interests in the acquired business are also initially measured at fair value. The Company recognizes goodwill if the aggregate fair value of the total purchase consideration and the noncontrolling interests is in excess of the aggregate fair value of the identifiable assets acquired and the liabilities assumed.
	Goodwill
	Goodwill represents the difference between the purchase price and the aggregate fair value of the identifiable assets acquired and the liabilities assumed in a business combination. The Company assesses goodwill impairment annually, in the fourth quarter of each fiscal year, and whenever events or changes in circumstances indicate that the carrying value of goodwill may exceed its fair value at the consolidated-level, which is the sole reporting unit. When assessing goodwill for impairment, the Company considers its market capitalization adjusted for a control premium and, if necessary, the Company’s discounted cash flow model, which involves significant assumptions and estimates, including the Company’s future financial performance, weighted-average cost of capital and interpretation of currently enacted tax laws. Circumstances that could indicate impairment and require the Company to perform an impairment test include a significant decline in the Company’s financial results, a significant decline in the Company’s market capitalization relative to its net book value, an unanticipated change in competition or the Company’s market share and a significant change in the Company’s strategic plans.
	Inventories
	Inventories include raw materials that include silicon wafers, process gasses, chemicals and other consumables used in solar cell production, solar cells, photovoltaic panels, inverters, mounting hardware and miscellaneous electrical components. Inventories also include work in process that includes raw materials partially installed and direct and indirect capitalized installation costs. Raw materials and work in process are stated at the lower of cost or market (on a first-in-first-out basis). Work in process primarily relates to solar energy systems that will be sold to customers, which are under construction and have yet to pass inspection.
	The Company also evaluates its inventory reserves on a quarterly basis and writes down the value of inventories for estimated excess and obsolete inventories based upon assumptions about future demand and market conditions.
	Solar Energy Systems, Leased and To Be Leased
	The Company is the operating lessor of the solar energy systems under leases that qualify as operating leases. The Company accounts for the leases in accordance with ASC 840, Leases. To determine lease classification, the Company evaluates lease terms to determine whether there is a transfer of ownership or bargain purchase option at the end of the lease, whether the lease term is greater than 75% of the useful life, or whether the present value of minimum lease payments exceed 90% of the fair value at lease inception. The Company utilizes periodic appraisals to estimate useful life and fair values at lease inception, and residual values at lease termination. Solar energy systems are stated at cost, less accumulated depreciation.
	Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the respective assets as follows.
			Useful Lives
	Solar energy systems leased to customers		30 years
	Initial direct costs related to customer solar energy		Lease term
	system lease acquisition costs		(10 to 20 years)
	Solar energy systems held for lease to customers are installed systems pending interconnection with the respective utility companies and will be depreciated as solar energy systems leased to customers when the respective systems have been interconnected and placed in service.
	Solar energy systems under construction represents systems that are under installation, which will be depreciated as solar energy systems leased to customers when the respective systems are completed, interconnected and subsequently leased to customers.
	Initial direct costs related to customer solar energy system lease acquisition costs are capitalized and amortized over the term of the related customer lease agreements.
	Presentation of Cash Flows Associated with Solar Energy Systems
The Company classifies cash flows associated with solar energy systems in accordance with ASC 230, Statement of Cash Flows. The Company determines the appropriate classification of cash payments related to solar energy systems depending on the activity that is likely to be the predominant source of cash flows for the item being paid for. Accordingly, the Company presents payments made in a period for costs incurred to install solar energy systems that will be leased to customers, including the payments for cost of the inventory that is utilized in such systems, as investing activities in the consolidated statement of cash flows. Payments made for inventory that will be utilized for solar energy systems that will be sold to customers are presented as cash flows from operations in the consolidated statement of cash flows.
Property, Plant and Equipment
Property, plant and equipment, including leasehold improvements, are stated at cost, less accumulated depreciation and amortization.
Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the respective assets as follows.
		Useful Lives
Furniture and fixtures		3-7 years
Vehicles		5 years
Computer hardware and software		3-10 years
Manufacturing & lab equipment		2 to 3 years
Buildings		20 years
Land & land use rights		50 years
Leasehold improvements are amortized over the shorter of the lease term or their estimated useful lives, currently seven years.
Repairs and maintenance costs are expensed as incurred.
Upon disposition, the cost and related accumulated depreciation of the assets are removed from property, plant and equipment and the resulting gain or loss is reflected in the consolidated statements of operations.
Long-Lived Assets
The Company’s long-lived assets include property, plant and equipment, solar energy systems, leased and to be leased, and intangible assets acquired through business combinations. Intangible assets with definite useful lives are amortized over their estimated useful lives, which range from 1 to 30 years.
In accordance with ASC 360, Property, Plant, and Equipment, the Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of a long-lived asset, or group of assets, as appropriate, may not be recoverable. If the aggregate undiscounted future net cash flows expected to result from the use and the eventual disposition of a long-lived asset is less than its carrying value, then the Company would recognize an impairment loss based on the discounted future net cash flows. No impairment charges were recorded for the years ended December 31, 2014, 2013 or 2012.
Capitalization of Software Costs
For costs incurred in development of internal use software, the Company capitalizes costs incurred during the application development stage. Costs related to preliminary project activities and post implementation activities are expensed as incurred. Internal-use software is amortized on a straight-line basis over its estimated useful life of 10 years. The Company evaluates the useful lives of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets.
Warranties
The Company warrants its products for various periods against defects in material or installation workmanship. The Company generally provides a warranty on the generating and non-generating parts of the solar energy systems it sells of typically between 10 to 30 years. The manufacturer’s warranty on the solar energy systems’ components, which is typically passed-through to customers, ranges from one to 25 years. The changes in the accrued warranty balance, recorded as a component of accrued and other current liabilities on the consolidated balance sheets, consisted of the following (in thousands):
		As of and for the
		Year Ended
		December 31,
		2014				2013
Balance - beginning of the period		$	7,502			$	4,019
Change in estimate (credited) charged to warranty expense			(468	)			1,514
Current year provision charged to warranty expense			2,022				2,257
Assumed warranty obligation arising from business			—				188
acquisitions
Less warranty claims			(449	)			(476	)
Balance - end of the period		$	8,607			$	7,502
Solar Energy Systems Performance Guarantees
The Company guarantees certain specified minimum solar energy production output for certain systems leased or sold to customers generally for a term of 20 years. The Company monitors the solar energy systems to ensure that these outputs are being achieved. The Company evaluates if any amounts are due to its customers. As of December 31, 2014 and 2013, the Company had recorded liabilities of $1.6 million and $1.0 million, respectively, under accrued and other current liabilities in the consolidated balance sheets, relating to these guarantees based on the Company’s assessment of its current exposure.
Deferred U.S. Treasury Grants Income
The Company is eligible for U.S. Treasury grants received or receivable on eligible property as defined under Section 1603 of the American Recovery and Reinvestment Act of 2009, as amended by the Tax Relief Unemployment Insurance Reauthorization and Job Creation Act of December 2010, which includes solar energy system installations, upon approval by the U.S. Treasury Department. However, to be eligible for U.S. Treasury grants, a solar energy system must have commenced construction in 2011 either physically or through the incurrence of sufficient project costs. For solar energy systems under lease pass-through fund arrangements, as described in Note 13, Lease Pass-Through Financing Obligation, the Company reduces the financing obligation and records deferred income for the U.S. Treasury grants which are paid directly to the investors upon receipt of the grants by the investors. The benefit of the U.S. Treasury grants is recorded as deferred income and is amortized on a straight-line basis over the estimated useful lives of the related solar energy systems of 30 years. The amortization of the deferred income is recorded as a reduction to depreciation expense, which is a component of the cost of revenue of operating leases and solar energy systems incentives in the consolidated statements of operations. A catch-up adjustment is recorded in the period in which the grant is approved by the U.S. Treasury Department or received by lease pass-through investors to recognize the portion of the grant that matches proportionally the amortization for the period between the date of placement in service of the solar energy systems and approval by the U.S. Treasury Department or receipt by lease pass-through investors of the associated grant. The changes in deferred U.S. Treasury grants income were as follows (in thousands):
Balance at January 1, 2012		$	137,434
U.S. Treasury grants received and receivable			112,520
U.S. Treasury grants received by investors under lease			58,685
pass-through fund arrangements
Amortized as a credit to depreciation expense			(10,379	)
Balance at December 31, 2012			298,260
U.S. Treasury grants received and receivable			124,404
U.S. Treasury grants received by investors under lease			20,599
pass-through fund arrangements
Amortized as a credit to depreciation expense			(15,454	)
Balance at December 31, 2013			427,809
U.S. Treasury grants received and receivable			342
Amortized as a credit to depreciation expense			(15,335	)
Balance at December 31, 2014		$	412,816
Of the balance outstanding as of December 31, 2014 and 2013, $397.5 million and $412.5 million, respectively, are classified as noncurrent deferred U.S. Treasury grants income in the consolidated balance sheets.
Deferred Investment Tax Credits Revenue
The Company’s solar energy systems are eligible for investment tax credits, or ITCs, that accrue to eligible property under the Internal Revenue Code. Under Section 50(d)(5) of the Internal Revenue Code and the related regulations, a lessor of qualifying property may elect to treat the lessee as the owner of such property for the purposes of claiming government ITCs associated with such property. These regulations enable the ITCs to be separated from the ownership of the property and allow the transfer of these ITCs. Under the lease pass-through fund arrangements, the Company can make a tax election to pass through the ITCs to the investor, who is the legal lessee of the property. The Company is therefore able to monetize the ITCs to investors who can utilize them in return for cash payments. The Company considers the monetization of ITCs to constitute one of the key elements of realizing the value associated with solar energy systems. The Company therefore views the proceeds from the monetization of ITCs to be a component of revenue generated from the solar energy systems.
For the lease pass-through fund arrangements, the Company allocates a portion of the aggregate payments received from the investor to the estimated fair value of the assigned ITCs and the balance to the future customer lease payments that are also assigned to the investors. The estimated fair value of the ITCs are determined by discounting the estimated cash flows impact of the ITCs using an appropriate discount rate that reflects a market interest rate.
The Company recognizes the revenue associated with the monetization of ITCs in accordance with ASC 605-10-S99, Revenue Recognition-Overall-SEC Materials. The revenue associated with the monetization of the ITCs is recognized when (1) persuasive evidence of an arrangement exists, (2) delivery has occurred or services have been rendered, (3) the sales price is fixed or determinable and (4) collection of the related receivable is reasonably assured. The ITCs are subject to recapture under the Internal Revenue Code if the underlying solar energy system either ceases to be a qualifying property or undergoes a change in ownership within five years of its placed in service date. The recapture amount decreases on the anniversary of the placed in service date. As the Company has an obligation to ensure the solar energy system is in service and operational for a term of five years to avoid any recapture of the ITCs, the Company recognizes revenue as the recapture provisions lapse assuming the other aforementioned revenue recognition criteria have been met. The monetized ITCs are initially recorded as deferred revenue on the consolidated balance sheet, and subsequently, one-fifth of the monetized ITCs is recognized as revenue from operating leases and solar energy systems incentives in the consolidated statement of operations on each anniversary of the solar energy system’s placed in service date over the next five years.
The Company guarantees its fund investors that in the event of a subsequent recapture of the ITCs by the taxing authority due to the Company’s noncompliance with the applicable ITC guidelines, the Company will compensate the investor for any recaptured credits. The Company has concluded that the likelihood of a recapture event is remote and consequently has not recorded any liability in the consolidated financial statements for any potential recapture exposure.
The balance of deferred investment tax credits revenue, which is included as part of deferred revenue in the consolidated balance sheets, as of December 31, 2014 and 2013 was $210.9 million and $139.5 million, respectively. For the year ended December 31, 2014 and 2013, the Company recognized $28.2 million and $0.5 million, respectively, of revenue related to the monetization of ITCs, which is included in operating leases and solar energy systems incentives revenue in the consolidated statements of operations. The Company had not recognized any revenue related to the monetization of ITCs prior to 2013.
Deferred Revenue
The Company records as deferred revenue any amounts that are collected from customers, including lease prepayments, in excess of revenue recognized. Deferred revenue also includes the portion of rebates and incentives received from utility companies and various local and state government agencies, which are recognized as revenue over the lease term, as well as the remote monitoring fee (discussed below), which is recognized as revenue ratably over the respective customer contract term. As of December 31, 2014 and 2013, deferred revenue related to customer payments, which is included in the deferred revenue balances in the consolidated balance sheets, amounted to $229.5 million and $186.9 million, respectively. As of December 31, 2014 and 2013, deferred revenue from rebates and incentives, which is included in the deferred revenue balances in the consolidated balance sheets, amounted to $169.6 million and $143.6 million, respectively. In addition, under MyPower customer contracts, all initial revenue associated with financed sales of solar energy systems are also recorded as a component of deferred revenue. As of December 31, 2014, deferred revenue from MyPower contracts amounted to $33.7 million.
Revenue Recognition
The Company provides design, installation, maintenance services and ongoing remote monitoring services for solar energy systems to residential and commercial customers. Customers generally purchase solar energy systems from the Company under fixed-price contracts or lease Company-owned solar energy systems, which also include remote monitoring services. A residential customer that purchases a solar energy system has the option to pay the full purchase price for the system at the time of purchase or finance the purchase through a 30-year loan from a wholly owned subsidiary of the Company, under the new MyPower program that the Company launched in the fourth quarter of 2014. The Company can also earn rebates, where available, that have been assigned to the Company by its customers on state-approved solar energy system installations sold to the customers, as well as rebates and incentives from utility companies and state and local governments on solar energy systems leased to customers or used to sell electricity to customers under power purchase agreements. The Company had also offered energy efficiency solutions aimed at improving residential energy efficiency and lowering overall residential energy costs. The energy efficiency services were comprised of energy efficiency evaluations and upgrades to homes and household appliances to improve energy efficiency.
Solar Energy Systems and Components Sales
For solar energy systems and components sales in which customers pay the full purchase price upon delivery of the system, the Company recognizes revenue, net of any applicable governmental sales taxes, in accordance with ASC 605-25, Revenue Recognition—Multiple-Element Arrangements, and ASC 605-10-S99, Revenue Recognition—Overall—SEC Materials. Revenue is recognized when (1) persuasive evidence of an arrangement exists, (2) delivery has occurred or services have been rendered, (3) the sales price is fixed or determinable and (4) collection of the related receivable is reasonably assured. Components comprise of photovoltaic panels and solar energy system mounting hardware. In instances where there are multiple deliverables in a single arrangement, the Company allocates the arrangement consideration to the various elements in the arrangement based on the relative selling price method. The Company recognizes revenue when it installs a solar energy system and the solar energy system passes inspection by the utility or the authority having jurisdiction, provided all other revenue recognition criteria have been met. Costs incurred on residential installations before the solar energy systems are completed are included in inventories as work in progress in the consolidated balance sheets.
The Company recognizes revenue for solar energy systems constructed for certain commercial customers according to ASC 605-35, Revenue Recognition—Construction-Type and Production Type Contracts. Revenue is recognized on a percentage-of-completion basis, based on the ratio of labor costs incurred to date to total projected labor costs. Provisions are made for the full amount of any anticipated losses on a contract-by-contract basis. The Company recognized $2.1 million, $2.9 million and $2.6 million of total losses for these types of contracts for the years ended December 31, 2014, 2013 and 2012, respectively. Costs in excess of billings are recorded where costs recognized are in excess of amounts billed to customers of purchased commercial solar energy systems. Costs in excess of billings as of December 31, 2014 and 2013 were $0.3 million and $0.1 million, respectively, and are included in prepaid expenses and other current assets in the consolidated balance sheets. Billings in excess of costs as of December 31, 2014 and 2013 were $0.2 million and $0.2 million, respectively, and are included in deferred revenue in the consolidated balance sheets.
For solar energy systems sold under a MyPower contract, the Company has determined that the arrangement consideration may not currently be fixed or determinable due to the lack of Company-specific or market history for similar programs with similar asset classes over an extended term. Accordingly, the Company initially defers the revenue associated with the sale of a solar energy system under a MyPower contract when it delivers a system that has passed inspection by the utility or the authority having jurisdiction. In instances where there are multiple deliverables in a single MyPower contract, the Company also allocates the arrangement consideration to the various elements in the contract based on the relative selling price method. Then, the Company recognizes revenue for the system over the term of the contract as the customer pays the loan’s principal and interest. The deferred revenue is included in the consolidated balance sheets under current portion of deferred revenue for the portion expected to be recognized as revenue in the next 12 months, and the non-current portion is included under deferred revenue, net of current portion. The Company records a note receivable when the customer secures a loan from a subsidiary of Company to finance the purchase.
The costs associated with solar energy systems sold under MyPower contracts are initially capitalized as deferred costs of revenue and subsequently recognized as a component of cost of revenue from solar energy systems and components sales, generally in proportion to the reduction of the loan’s outstanding principal. The deferred cost of revenue is included in the consolidated balance sheets under prepaid expenses and other current assets for the portion expected to be recognized as cost of revenue in the next twelve months, and the non-current portion is included under other assets.
The deferred revenue activity under MyPower was as follows (in thousands):
		As of and for the
		Year Ended
		December 31,
		2014
Balance - beginning of the period		$	—
MyPower agreements executed in the period			33,738
Recognized in the period			(87	)
Balance - end of the period		$	33,651
Of the ending balance, $1.0 million is included in the consolidated balance sheets under current portion of deferred revenue, as of December 31, 2014. The balances in the table above do not include amounts allocated to remote monitoring services, other deliverables or sales taxes.
The deferred cost of revenue activity under MyPower was as follows (in thousands):
		As of and for the
		Year Ended
		December 31,
		2014
Balance - beginning of the period		$	—
MyPower agreements executed in the period			13,614
Recognized in the period			(43	)
Balance - end of the period		$	13,571
Of the ending balance, $0.4 million is included in the consolidated balance sheets under prepaid expenses and other current assets, as of December 31, 2014.
Operating Leases and Power Purchase Agreements
The Company is the lessor under lease agreements for solar energy systems, which are accounted for as operating leases in accordance with ASC 840. The Company records operating lease revenue from minimum lease payments, including upfront rebates and incentives earned from such systems, on a straight-line basis over the life of the lease term, assuming all other revenue recognition criteria are met. For incentives that are earned based on amount of electricity generated by the system, the Company records revenue as the amounts are earned.
The difference between the payments received and the revenue recognized is recorded as deferred revenue in the consolidated balance sheets.
For solar energy systems where customers purchase electricity from the Company under power purchase agreements, the Company has determined that these agreements should be accounted for, in substance, as operating leases pursuant to ASC 840. Revenue is recognized based upon the amount of electricity delivered at rates specified under the contracts, assuming all other revenue recognition criteria are met.
The portion of rebates and incentives recognized within operating leases and solar energy systems incentives revenue for the years ended December 31, 2014, 2013 and 2012 was $33.4 million, $26.6 million and $18.2 million, respectively.
Initial direct costs related to customer solar energy system lease acquisition costs (the incremental cost of contract administration, referral fees and sales commissions) are capitalized as an element of solar energy systems and amortized over the term of the related lease or power purchase agreement, which generally ranges from 10 to 20 years. Refer to Note 7, Solar Energy Systems, Leased and To Be Leased – Net, for a summary of initial direct costs related to customer solar energy system lease acquisition costs.
Remote Monitoring Services
The Company provides solar energy system remote monitoring services, which are generally bundled with both sales and leases of solar energy systems. The Company allocates revenue between remote monitoring services and the other elements in a bundled sale of a solar energy system using the relative selling price method. The selling prices used in the allocation are determined by reference to the prices charged by third parties for similar services and products on a standalone basis. For remote monitoring services bundled with a sale of a solar energy system, the Company recognizes the revenue allocated to remote monitoring services over the term specified in the associated contract or over the warranty period of the solar energy system if the contract does not specify the term. To date, remote monitoring services revenue has not been material and is included in the consolidated statements of operations under both operating leases and solar energy systems incentives revenue, when remote monitoring services are bundled with leases of solar energy systems, and solar energy system sales revenue, when remote monitoring services are bundled with sales of solar energy systems.
Sale-Leaseback
The Company is party to master lease agreements that provide for the sale of solar energy systems to third parties and the simultaneous leaseback of the systems, which the Company then subleases to customers. In sale-leaseback arrangements, the Company first determines whether the solar energy system under the sale-leaseback arrangement is “integral equipment.” A solar energy system is determined to be integral equipment when the cost to remove the system from its existing location, including the shipping and reinstallation costs of the solar energy system at the new site, including any diminution in fair value, exceeds ten percent of the fair value of the solar energy system at the time of its original installation. When the leaseback arrangements expire, the Company has the option to purchase the solar energy system, and in most cases, the lessor has the option to sell the system back to the Company, though in some instances the lessor can only sell the system back to the Company prior to expiration of the arrangement.
For solar energy systems that the Company has determined to be integral equipment, the Company has concluded that these rights create a continuing involvement. Therefore, the Company uses the financing method to account for the sale-leaseback of such solar energy systems. Under the financing method, the Company does not recognize as revenue any of the sale proceeds received from the lessor that contractually constitutes a payment to acquire the solar energy system. Instead, the Company treats any such sale proceeds received as financing capital to install and deliver the solar energy system and accordingly records the proceeds as a sale-leaseback financing obligation in the consolidated balance sheets. The Company allocates the leaseback payments made to the lessor between interest expense and a reduction to the sale-leaseback financing obligation. Interest on the financing obligation is calculated using the Company’s incremental borrowing rate at the inception of the arrangement on the outstanding financing obligation. The Company determines its incremental borrowing rate by reference to the interest rates that it would obtain in the financial markets to borrow amounts equal to the sale-leaseback financing obligation over a term similar to the master lease term.
For solar energy systems that the Company has determined not to be integral equipment, the Company determines if the leaseback is classified as a capital lease or an operating lease. For leasebacks classified as capital leases, the Company initially records a capital lease asset and capital lease obligation in the consolidated balance sheet equal to the lower of the present value of the future minimum leaseback payments or the fair value of the solar energy system. For capital leasebacks, the Company does not recognize any revenue but defers the gross profit comprising of the net of the revenue and the associated cost of sale. For leasebacks classified as operating leases, the Company recognizes a portion of the revenue and the associated cost of sale and defers the portion of revenue and cost of sale that represents the gross profit that is equal to the present value of the future minimum lease payments over the master leaseback term. For both capital and operating leasebacks, the Company records the deferred gross profit in the consolidated balance sheet as deferred income and amortizes the deferred income over the leaseback term as a reduction to the leaseback rental expense included in operating leases and solar energy systems incentives cost of revenue in the consolidated statement of operations.
Cost of Revenue
Operating leases and solar energy systems incentives cost of revenue is primarily comprised of depreciation of the cost of leased solar energy systems reduced by amortization of U.S. Treasury grants income, maintenance costs associated with those systems and amortization of initial direct lease costs associated with those systems.
Solar energy systems and components sales cost of revenue includes direct and indirect material and labor costs, warehouse rent, freight, warranty expense, depreciation on vehicles and other overhead costs. In addition, for solar energy systems and components sales accounted for under the percentage-of-completion method, cost of revenue includes the full amount of any anticipated future losses on a contract-by-contract basis. However, for solar energy systems sold under MyPower contracts, the cost of revenue in a period is recognized in proportion to the revenue recognized for each system in the period.
Advertising Costs
Advertising costs are expensed as incurred and are included as an element of sales and marketing expense in the consolidated statement of operations. The Company incurred advertising costs of $3.4 million, $0.5 million and $3.8 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Income Taxes
The Company accounts for income taxes under an asset and liability approach. Deferred income taxes reflect the impact of temporary differences between assets and liabilities recognized for financial reporting purposes and the amounts recognized for income tax reporting purposes, net operating loss, or NOL, carryforwards and other tax credits measured by applying currently enacted tax laws. A valuation allowance is provided when necessary to reduce deferred tax assets to an amount that is more likely than not to be realized. The Company is eligible for federal investment tax credits. The Company accounts for federal investment tax credits under the flow-through method of accounting. As permitted in ASC 740-10-25-46, under the “flow-through” method of accounting, the tax benefit from an investment tax credit is recorded as a reduction of federal income taxes in the period that the credit is generated.
The Company determines whether a tax position is more likely than not to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. The Company uses a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained upon tax authority examination, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon ultimate settlement.
The Company’s policy is to include interest and penalties related to unrecognized tax benefits, if any, within the provision for taxes in the consolidated statements of operations.
Comprehensive Income (Loss)
The Company accounts for comprehensive income (loss) in accordance with ASC 220, Comprehensive Income. Under ASC 220, the Company is required to report comprehensive income (loss), which includes net income (loss) as well as other comprehensive income (loss). There were no significant other comprehensive income (losses) and no significant differences between comprehensive loss as defined by ASC 220 and net loss as reported in the consolidated statements of operations, for the periods presented.
Solar Renewable Energy Credits
The Company accounts for solar renewable energy credits, or SRECs, when they are minted by government agencies, purchased by the Company or sold to third parties. For SRECs generated by the Company’s solar energy systems and minted by government agencies, the Company does not recognize any specifically identifiable costs for those SRECs. For SRECs purchased by the Company, the Company carries these SRECs at their purchase price, subject to testing for impairment. When a SREC is sold to a third party, the Company recognizes operating leases and solar energy systems incentives revenue upon transfer of the SREC to the third party, and the cost of the SREC, if any, is recorded to operating leases and solar energy systems incentives cost of revenue.
Stock-Based Compensation
The Company accounts for stock-based compensation costs under the provisions of ASC 718, Compensation—Stock Compensation, which requires the measurement and recognition of compensation expense related to the fair value of stock-based compensation awards that are ultimately expected to vest. Stock-based compensation expense recognized includes the compensation cost for all share-based payments granted to employees based on the grant date fair value estimated in accordance with the provisions of ASC 718. ASC 718 is also applied to awards modified, repurchased, or canceled during the periods reported.
The Company applies ASC 718 and ASC Subtopic 505-50, Equity-Based Payments to Non Employees, to options and other stock-based awards issued to nonemployees. In accordance with ASC 718 and ASC Subtopic 505-50, the Company uses the Black-Scholes option-pricing model to measure the fair value of the options at the measurement date. The measurement of stock-based compensation is subject to periodic adjustments as the awards vest and the resulting change in fair value is recognized in the consolidated statements of operations in the period the related services are rendered.
Noncontrolling Interests and Redeemable Noncontrolling Interests
Noncontrolling interests and redeemable noncontrolling interests represent third-party interests in the net assets under certain funding arrangements, or funds, that the Company has entered into to finance the cost of solar energy systems under operating leases. The Company has determined that the contractual provisions in the funds represent substantive profit sharing arrangements. The Company has further determined that the appropriate methodology for calculating the noncontrolling interest and redeemable noncontrolling interests balances that reflect the substantive profit sharing arrangements is a balance sheet approach using the hypothetical liquidation at book value, or HLBV, method. The Company therefore determines the amount of the noncontrolling interests and redeemable noncontrolling interests in the net assets at each balance sheet date using the HLBV method, which is presented on the consolidated balance sheets as noncontrolling interests in subsidiaries and redeemable noncontrolling interests in subsidiaries. Under the HLBV method, the amounts reported as noncontrolling interests and redeemable noncontrolling interests in the consolidated balance sheets represent the amounts the third parties would hypothetically receive at each balance sheet date under the liquidation provisions of the funds, assuming the net assets of the funds were liquidated at the recorded amounts determined in accordance with GAAP and distributed to the third parties. The third parties’ interests in the results of operations of the funds is determined as the difference in the noncontrolling interests and redeemable noncontrolling interests balance in the consolidated balance sheets between the start and end of each reporting period, after taking into account any capital transactions between the funds and the third parties. However, the redeemable noncontrolling interests balance is at least equal to the redemption amount. The noncontrolling interests and redeemable noncontrolling interests balance is presented as a component of permanent equity in the consolidated balance sheets or as temporary equity in the mezzanine section of the consolidated balance sheets as redeemable noncontrolling interests when the third-parties have the right to redeem their interests in the funds for cash or other assets.
Segment Information
Operating segments are defined as components of a company about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or decision making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is the executive team, which is comprised of the chief executive officer, the chief technology officer, the chief revenue officer, chief operating officer and the chief financial officer. Based on the financial information presented to and reviewed by the chief operating decision maker in deciding how to allocate the resources and in assessing the performance of the Company, the Company has determined that it has a single operating and reporting segment: solar energy products and services. The Company’s principal operations, revenue and decision-making functions are located in the United States.
Basic and Diluted Net Income (Loss) Per Share
The Company’s basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period.
Prior to the Company’s initial public offering of its common stock, its convertible redeemable preferred stock was entitled to receive dividends of up to $0.01 per share if dividends would have been declared on the common stock and thereafter would have participated pro rata on an as-converted basis with the common stockholders on any distributions to common stockholders. The convertible redeemable preferred stock was therefore a participating security. As a result, the Company calculated the net income (loss) per share using the two-class method. Accordingly, the net income (loss) attributable to common stockholders was derived from the net income (loss) for the period and, in periods in which the Company had net income attributable to common stockholders, an adjustment was made for the noncumulative dividends and allocations of earnings to participating securities based on their outstanding shareholder rights. Under the two-class method, the net loss attributable to common stockholders was not allocated to the convertible redeemable preferred stockholders as the convertible redeemable preferred stock did not have a contractual obligation to share in the Company’s losses.
The diluted net income (loss) per share attributable to common stockholders is computed by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method or the if-converted method, as applicable. In periods when the Company incurred a net loss attributable to common stockholders, convertible redeemable preferred stock, stock options, restricted stock units, warrants to purchase common stock, warrants to purchase convertible redeemable preferred stock and convertible senior notes were considered to be common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive.
Recently Issued Accounting Standards
In May 2014, the FASB issued Accounting Standards Update, or ASU, No. 2014-09, Revenue from Contracts with Customers (Topic 606), to replace the existing revenue recognition criteria for contracts with customers and to establish the disclosure requirements for revenue from contracts with customers. The ASU is effective for interim and annual periods beginning after December 15, 2016. Adoption of the ASU is either retrospective to each prior period presented or retrospective with a cumulative adjustment to retained earnings or accumulated deficit as of the adoption date. The Company is currently assessing the impact of the ASU on its consolidated financial statements.
In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40), to provide guidance within GAAP requiring management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and requiring related disclosures. The ASU is effective for annual periods ending after December 15, 2016. The Company believes that the ASU will have no impact on its consolidated financial statements.
In February 2015, the FASB issued ASU No. 2015-02, Consolidation (Topic 810) — Amendments to the Consolidation Analysis, to amend the criteria for consolidation of certain legal entities. The ASU is effective for interim and annual periods beginning after December 15, 2015. Adoption of the ASU is either retrospective to each prior period presented or retrospective with a cumulative adjustment to retained earnings or accumulated deficit as of the adoption date. The Company is currently assessing the impact of the ASU on its consolidated financial statements.

Acquisition

Acquisition	12 Months Ended
	Dec. 31, 2014
Business Combinations [Abstract]
Acquisition	3. Acquisitions
	Paramount Energy
	On September 6, 2013, the Company purchased certain assets of Paramount Energy Solutions, LLC, or Paramount Energy. Paramount Energy was a leading direct-to-consumer marketer and was one of the Company’s channel partners through a customer referral arrangement. The acquired assets included Paramount Energy’s interest in a financing fund that it had formed with an investor that is also the investor in some of the Company’s existing funds, executed end-user customer agreements together with the associated solar energy systems in various stages of completion and various databases and arrangements used by Paramount Energy in its acquisition of new customers. The acquisition was meant to enable the Company to develop and offer its solar energy systems directly to a broader customer base and to better compete with other energy producers, as well as to drive a lower cost of customer acquisition. In connection with the acquisition, the former chief executive officer of Paramount Energy joined the Company as the chief revenue officer. The purchase consideration comprised of $3.7 million in cash and 3,674,565 shares of the Company’s common stock, inclusive of 379,146 shares held in escrow and released in September 2014 to cover any general representations and warranties, with an aggregate fair value of $108.8 million based on the closing price of the Company’s common stock on the acquisition date. Additionally, the Company was obligated to pay to the sellers an additional $4.0 million after the acquisition date, of which $3.2 million was paid in October 2013 and the balance in January 2014.
	The following table summarizes the fair value of the purchase consideration as of the acquisition date (in thousands):
	Cash	$	3,700
	Common stock		108,804
	Deferred consideration		4,039
	Total purchase consideration	$	116,543
	The following table summarizes the fair value of the assets acquired, liabilities assumed and the noncontrolling interest as of the acquisition date (in thousands):
	Cash	$	12
	Deposits and prepaid costs		409
	Solar energy systems under construction		2,130
	Solar energy systems, leased and to be leased		5,475
	Property and equipment		96
	Intangible assets		58,725
	Deferred revenue		(207	)
	Total identifiable net assets at fair value		66,640
	Noncontrolling interest		(549	)
	Goodwill		50,452
	Total purchase consideration	$	116,543
	The noncontrolling interest represents the fair value of an investor’s interest in the financing fund acquired as part of the acquisition. The Company has determined that it is the primary beneficiary of the financing fund and, accordingly, consolidates the financial position and results of operations of the financing fund in the consolidated financial statements.
	The goodwill recognized was primarily attributable to expected synergies, anticipated cost savings and efficiencies and the assembled workforce of Paramount Energy. The full amount of the goodwill is deductible for tax purposes.
	The following table summarizes the acquired intangible assets as of the acquisition date:
			Fair Value		Weighted-
					Average
					Useful Life
			(in thousands)		(in years)
	Marketing database	$	17,427		5
	PowerSaver agreement		17,077		10
	Solar energy systems backlog		12,434		30
	Non-compete agreement		6,959		5
	Mortgage database		4,628		3
	Funding commitment by fund investor		200		5
	Total	$	58,725
	Zep Solar
	In December 2013, the Company completed its acquisition of Zep Solar, Inc., or Zep Solar. Zep Solar designs and supplies solar energy system mounting solutions for photovoltaic panels and also licenses its patented technology to other third parties. Zep Solar contracts with manufacturers in China to produce its products and it was a key supplier to the Company. The acquisition is expected to enable the Company to control the design and manufacture of the Zep Solar products that are key components in the installation of the Company’s solar energy systems. The Company expects that the acquisition will lead to improved efficiencies and cost reductions. In connection with the acquisition, certain former employees of Zep Solar accepted employment with the Company.
	The acquisition consideration was comprised of $2.4 million in cash, 2,751,793 shares of the Company’s common stock and the assumption of fully vested options to purchase 303,151 shares of the Company’s common stock, which replaced certain fully vested options of Zep Solar’s common stock. The following table summarizes the determination of the fair value of the purchase consideration in the acquired business as of the acquisition date (in thousands):
	Cash	$	2,368
	Common stock		140,562
	Common stock options		14,893
	Total purchase consideration	$	157,823
	The following table summarizes the fair value of the assets acquired and liabilities assumed as of the acquisition date (in thousands):
	Cash	$	2,300
	Accounts receivable		1,293
	Inventory		4,255
	Property and equipment		366
	Other assets		251
	Accounts payable and other liabilities assumed		(9,646	)
	Deferred tax liabilities		(24,797	)
	Intangible assets		86,000
	Total identifiable net assets at fair value		60,022
	Goodwill		97,801
	Total purchase consideration	$	157,823
	The goodwill recognized was primarily attributable to efficiencies and cost savings that the Company expects to achieve from leveraging Zep Solar’s technology in its installation of solar energy systems. The acquisition of Zep Solar technology will allow the Company to reduce the costs of purchasing solar energy system mounting hardware, minimize the installation time of solar energy systems and lead to improve efficiencies and profitability. The full amount of the goodwill is not deductible for tax purposes.
	The following table summarizes the acquired intangible assets as of the acquisition date:
			Fair Value		Weighted-
					Average
					Useful Life
			(in thousands)		(in years)
	Developed technology	$	60,100		7
	Trademarks and trade names		24,700		7
	Customer orders backlog		700		1
	Internally developed software		500		3
	Total	$	86,000
Silevo
On September 23, 2014, the Company completed its acquisition of Silevo a designer and manufacturer of high performance solar cells that are manufactured into photovoltaic panels. Silevo’s primary operations are in the United States, where it carries-out research and development activities as well as sales of products, and in China, where it is the managing partner in a joint venture that manufactures the solar cells for the subsequent contract manufacturing of high performing photovoltaic panels. The acquisition is expected to enable the Company to manage its supply chain and control the design and manufacturing of solar cells and photovoltaic panels that are a key component of the Company’s solar energy systems, as well as enable the Company to utilize and combine Silevo’s technology with economies of scale to achieve significant cost reductions.
The purchase consideration was comprised of $0.3 million in cash and 2,284,070 shares of the Company’s common stock, inclusive of 429,301 shares held in escrow until November 2015 to secure the indemnification obligations of Silevo’s former stockholders, with an aggregate fair value of $138.0 million based on the closing price of the Company’s common stock on the acquisition date. Additionally, the Company may pay up to approximately $150.0 million in additional shares of the Company’s common stock to Silevo’s former stockholders, subject to the achievement of specified production milestones, as contingent consideration. No amounts would be payable for any milestones not achieved. The Company has estimated the fair value of the contingent consideration to be $115.3 million using a probability-weighted discounted cash flow methodology. The Company also issued Silevo employees rights to receive SolarCity common stock as replacement for unvested Silevo common stock options that vest as the employees provide future services to the Company. Purchase consideration included $15.8 million that had previously been advanced to Silevo. The table below summarizes the preliminary determination of the fair value of the purchase consideration as of the acquisition date (in thousands):
Cash	$	326
Common stock		137,958
Restricted stock units issued to replace Silevo's unvested stock		132
options
Amounts advanced to Silevo prior to acquisition and costs paid		16,760
on behalf of sellers at acquisition
Closing consideration payable		413
Contingent consideration payable		115,319
Total purchase consideration	$	270,908
The Company is in the process of reviewing a third-party valuation of the contingent consideration payable. Accordingly, the preliminary fair values reflected in the table above are subject to change.
The following table summarizes the preliminary assessment of the fair values of the assets acquired, the liabilities assumed and the noncontrolling interests as of the acquisition date (in thousands). The Company is in the process of reviewing a third-party valuation of the assets acquired including the intangible assets, inventory, property, plant and equipment, the liabilities and term loan assumed and the noncontrolling interests. Accordingly, the preliminary fair values reflected in the following table are subject to change:
Cash	$	2,899
Accounts receivable		642
Inventories		8,182
Prepaid and other assets		899
Property, plant and equipment		28,281
Accounts payable and other liabilities		(5,427	)
Term loan		(9,103	)
Deferred tax liabilities		(27,332	)
Intangible assets		119,000
Total identifiable net assets at fair value		118,041
Redeemable noncontrolling interests		(14,174	)
Goodwill		167,041
Total purchase consideration	$	270,908
The goodwill recognized was primarily attributable to the value of expected synergies, efficiencies and cost savings that the Company expects to achieve in leveraging Silevo’s technology in the volume manufacturing of high efficiency photovoltaic panels, in addition to the value of the assembled workforce and the manufacturing experience of Silevo. The acquisition of Silevo’s technology is anticipated to reduce the Company’s costs of procuring photovoltaic panels, reduce the number of photovoltaic panels and other components used in solar energy systems, reduce the installation time of solar energy systems and improve efficiencies and profitability. The full amount of the goodwill is not deductible for tax purposes.
Subsequent to the acquisition date, the Company obtained valuations for the intangible assets and contingent consideration as well as completed studies on tax implications of the acquisition, including the amount of net operating losses available for future utilization by the Company. On the basis of the information obtained, the Company revised the estimated fair value of the contingent consideration and the deferred taxes arising from the acquisition by increasing the previously disclosed fair value of the contingent consideration by $19.8 million and increasing the deferred tax liability by $3.6 million. These resulted in an increase to goodwill by $23.4 million. The adjustments did not affect the previously reported cash flows. As a result of the adjustments, the Company released additional deferred tax asset valuation allowances to the consolidated statements of operations. The impact of the adjustments on the consolidated statements of operations was to reduce the net loss by $3.6 million. The revised amounts are reflected in the tables above.
The following table summarizes the acquired intangible assets as of the acquisition date:
				Weighted-
				Average
	Fair Value			Useful Life
	(in thousands)			(in years)
Developed technology	$	115,000			10
Build-to-suit lease arrangement		4,000			10
Total	$	119,000
The consolidated statement of operations for the year ended December 31, 2014 includes revenue of $1.1 million and a net loss of $9.7 million from Silevo. In addition, the Company incurred $3.5 million of general and administrative expenses for acquisition-related legal and other professional services fees and the termination of a pre-existing contract.
The unaudited pro forma financial information for the acquisition of Silevo, as if it had been consummated on January 1, 2013, is as follows (in thousands):
	Year Ended December 31,
	2014			2013
Total revenue	$	259,693		$	164,996
Net loss attributable to common stockholders	$	(109,401	)	$	(95,764	)
Net loss per share attributable to common	$	(1.15	)	$	(1.17	)
stockholders, diluted
The pro forma financial information is hypothetical and based on the combined results of operations of Silevo and the Company with adjustments primarily for the release of deferred tax asset valuation allowances, the interest expense on the convertible notes issued by Silevo as the convertible notes are assumed to have converted and been settled with the Company’s common stock on January 1, 2013, the amortization of the acquired intangible assets, the accretion on the contingent consideration payable, acquisition expenses and the income allocated to Silevo’s noncontrolling interests. The pro forma financial information is not necessarily indicative of the actual consolidated results of operations in prior or future periods had the acquisition actually consummated on January 1, 2013. For instance, the Company anticipates that it will consume the vast majority of Silevo’s products for the near future. Generally, Silevo products sold to the Company will be initially capitalized as inventory and eventually recognized as either a cost of leased solar energy systems or a cost of sold solar energy systems.
Silevo’s Joint Venture in China
Silevo operates a joint venture, Silevo China Company Limited, or the JV, with three other Chinese legal entities, or the JV Partners, to develop, manufacture and market high performance solar cells. Silevo owns approximately 65.7% of the outstanding capital of the JV, and the rest is owned by the JV Partners. Silevo has a Manufacturing Services and Technology Licensing Agreement with the JV to acquire solar cells on a “cost-plus” basis. The JV is required to obtain Silevo’s consent to sell products to any third-party. The agreement had an initial term of one year and automatically renews for successive one-year periods.
The Company has determined that the JV is a VIE and that Silevo is the primary beneficiary of the JV since the variable interests held by Silevo empower it to direct the activities that most significantly impact the joint venture’s economic performance. In reaching this determination, the Company considered the significant control exercised by Silevo over the JV’s Board of Directors, management and the daily operations of the JV.
Silevo has the right to acquire the JV Partners’ interests in the JV at any time within five years from the date of their initial capital contribution. The JV Partners have the right to sell all or part of their interests in the JV to Silevo if the JV does not meet certain conditions set out in the JV contract, which include meeting set production targets within a specified time frame. The JV did not meet some of those targets, and as such, the option is currently exercisable. The JV is not allowed to make a profit distribution to investors prior to the full exit of JV Partners from their investments in the JV.
Since Silevo has been determined to be the primary beneficiary of the JV, the JV’s assets, liabilities and results of operations are included in the Company’s consolidated financial statements. The JV Partners’ interests in the JV are reflected in redeemable noncontrolling interests on the consolidated balance sheets. The JV Partners’ interests in the JV were recorded at fair value as of the Silevo acquisition date, which considered the JV Partners’ share of the JV’s enterprise value and the value of the JV Partners’ option to sell their interests in the JV to Silevo.
The following table summarizes the carrying amounts of the JV’s assets and liabilities included in the Company’s consolidated balance sheet at December 31, 2014 (in thousands):
Cash	$	1,401
Inventories		614
Prepaid and other current assets		1,224
Property, plant and equipment - net		24,286
Total assets	$	27,525
Accounts payable	$	2,748
Accrued and other current liabilities		633
Current portion of long-term debt		9,134
Total liabilities	$	12,515

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	4. Goodwill and Intangible Assets
	Intangible Assets
	The following is a summary of intangible assets as of December 31, 2014 (in thousands):
											Transfers to
		Weighted-									solar energy
		average									systems,			Write-offs
		useful life						Accumulated			leased and to be			and
		(in years)			Gross			amortization			leased			cancellations			Net
	Developed technology - Silevo		10		$	115,000		$	(3,096	)	$	—		$	—		$	111,904
	Developed technology - Zep Solar		7			60,100			(9,070	)		—			—			51,030
	Trademarks and trade names		7			24,700			(3,728	)		—			—			20,972
	Marketing database		5			17,427			(4,599	)		—			—			12,828
	PowerSaver agreement		10			17,077			(2,253	)		—			—			14,824
	Solar energy systems backlog		30			12,434			—			(10,755	)		(1,679	)		—
	Non-compete agreement		5			6,959			(1,836	)		—			—			5,123
	Mortgage database		3			4,628			(2,035	)		—			—			2,593
	Build-to-suit lease arrangement		10			4,000			(108	)		—			—			3,892
	Customer orders backlog		1			700			(700	)		—			—			—
	Internally developed software		3			500			(176	)		—			—			324
	Funding commitment		5			200			(53	)		—			—			147
	Total		9.35		$	263,725		$	(27,654	)	$	(10,755	)	$	(1,679	)	$	223,637
	The following is a summary of intangible assets as of December 31, 2013 (in thousands):
											Transfers to
		Weighted-									solar energy
		average									systems,			Write-offs
		useful life						Accumulated			leased and to be			and
		(in years)			Gross			amortization			leased			cancellations			Net
	Developed technology - Zep Solar		7		$	60,100		$	(485	)	$	—		$	—		$	59,615
	Trademarks and trade names		7			24,700			(199	)		—			—			24,501
	Marketing database		5			17,427			(1,113	)		—			—			16,314
	PowerSaver agreement		10			17,077			(546	)		—			—			16,531
	Solar energy systems backlog		30			12,434			—			(10,615	)		(1,429	)		390
	Non-compete agreement		5			6,959			(444	)		—			—			6,515
	Mortgage database		3			4,628			(493	)		—			—			4,135
	Customer orders backlog		1			700			(89	)		—			—			611
	Internally developed software		3			500			(9	)		—			—			491
	Funding commitment		5			200			(13	)		—			—			187
	Total		8.82		$	144,725		$	(3,391	)	$	(10,615	)	$	(1,429	)	$	129,290
	Developed Technology – Silevo
	Silevo developed technology represents high performance solar cell technology acquired through the Silevo acquisition. The high performance technology would allow the Company to achieve improved solar energy system performance and reduce the overall deployment cost per watt of the solar energy systems sold or leased. In addition, the high performance technology would increase the Company’s market opportunity to a broader customer base who would benefit economically from more efficient solar energy systems.
	Developed Technology – Zep Solar
	Zep Solar developed technology represents solar panel interlocking technology that includes a rail-free installation system, auto-grounding connections and a rapid, drop-in module installation design. These features allow solar energy systems to be installed easily and produce significant performance-based and aesthetic improvements compared to other solar energy system installation technologies.
	Trademarks and Trade Names
	Trademarks and trade names are related to established market recognition from acquired businesses.
	Marketing Database
	The marketing database is a comprehensive platform for targeted marketing, including a prospective customer scoring engine, a marketing campaign manager and monthly updates. The prospective customer scoring engine improves the results of marketing initiatives by predicting which customer leads in the marketing database will respond favorably to a particular marketing campaign. The marketing campaign manager monitors the results of marketing campaigns and provides feedback for optimizing future marketing campaigns.
	PowerSaver Agreement
	Under the PowerSaver program, Fannie Mae makes available additional loans of up to $25,000 to eligible Fannie Mae borrowers. The additional loan amounts can only be used for energy efficiency projects that include the installation of solar energy systems. The PowerSaver program provides an additional source of financing for customers and therefore helps broaden the Company’s customer base. Under the PowerSaver agreement, the Company is provided with the exclusive right to market solar energy systems to the customers of Paramount Mortgage, an affiliate of Paramount Energy.
	Solar Energy Systems Backlog
	Solar energy systems backlog represents the value attributable to the contractual arrangements entered into between Paramount Energy and its customers to install solar energy systems for which the installation had not commenced as of the acquisition date. The arrangements were acquired by the Company. This balance is transferred to solar energy systems, leased and to be leased, as the solar energy systems are installed and placed in service and subsequently depreciated as cost of solar energy systems over the estimated useful lives of the solar energy systems of 30 years.
	Non-Compete Agreement
	Certain former key employees of businesses acquired by the Company became employees of the Company and executed non-compete agreements with the Company.
	Mortgage Database
	The mortgage database contains data pertaining to households that the Company can directly market to.
	Build-to-Suit Lease Arrangement
	The build-to-suit lease arrangement represents an agreement with an affiliate of the State of New York whereby the affiliate will construct a facility to manufacture photovoltaic panels, procure manufacturing equipment for use in the facility and subsequently lease the facility and the manufacturing equipment to the Company. The Company is obligated to meet certain operational milestones, including meeting specified hiring and capital expenditure targets, among others, over the initial lease term. The build-to-suit lease arrangement is further discussed in Note 22, Commitments and Contingencies.
	Internally Developed Software
	Internally developed software consists of Zep Solar’s Zepulator System Designer, or Zepulator, online application. Zepulator can project the size, scope, layout, materials and costs of potential solar energy system installations, which assists with optimizing solar energy system installations.
	All intangible assets, with the exception of the solar energy systems backlog, are amortized over their estimated useful lives. The changes to the carrying value of intangible assets were as follows (in thousands):
		Year Ended December 31,
		2014			2013
	Balance - beginning of the period	$	129,290		$	—
	Acquisition of Paramount Energy		—			58,725
	Acquisition of Zep Solar		—			86,000
Acquisition of Silevo		119,000			—
Amortization		(24,263	)		(3,391	)
Transfers to solar energy systems, leased and to be leased		(140	)		(10,615	)
Write-offs and cancellations		(250	)		(1,429	)
Balance - end of the period	$	223,637		$	129,290
During the year ended December 31, 2014, total amortization expense for intangible assets was $24.3 million, of which $10.0 million is included in operating leases and solar energy systems incentives cost of revenue, $2.6 million is included in solar energy systems and components sales cost of revenue and $11.7 million is included in sales and marketing expense, in the consolidated statements of operations. As of December 31, 2013, total amortization expense for intangible assets was $3.4 million, of which $0.6 million is included in operating leases and solar energy systems incentives cost of revenue and $2.8 million is included in sales and marketing expense, in the consolidated statements of operations. No intangible assets were impaired during the years ended December 31, 2014 and 2013. However, the Company wrote-off $0.3 million and $1.4 million of solar energy systems backlog related to contracts cancelled after acquisition, during the years ended December 31, 2014 and 2013, respectively, which was recorded in sales and marketing expense in the consolidated statements of operations. As of December 31, 2014, total future amortization expense for intangible assets was as follows (in thousands):
2015	$	32,349
2016		31,846
2017		30,639
2018		29,068
2019		25,722
Thereafter		74,013
Total	$	223,637
Goodwill
The changes to the carrying value of goodwill were as follows (in thousands):
	Year Ended December 31,
	2014			2013
Balance - beginning of the period	$	148,879		$	626
Acquisition of Paramount Energy		—			50,452
Acquisition of Zep Solar		—			97,801
Acquisition of Silevo		167,041			—
Balance - end of the period	$	315,920		$	148,879
The Company did not recognize any impairment of goodwill during the years ended December 31, 2014, 2013 and 2012.

Noncancelable_Operating_Lease_

Noncancelable Operating Lease Payments Receivable	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Noncancelable Operating Lease Payments Receivable	5. Noncancelable Operating Lease Payments Receivable
	As of December 31, 2014, future minimum lease payments to be received from customers under noncancelable operating leases for each of the next five years and thereafter were as follows (in thousands):
	2015	$	54,759
	2016		54,076
	2017		54,827
	2018		55,681
	2019		56,547
	Thereafter		762,762
	Total	$	1,038,652
	The Company enters into power purchase agreements with its customers that are accounted for, in substance, as leases. These customers are charged solely based on actual power produced by the installed solar energy system at a predefined rate per kilowatt-hour of power produced. The future payments from such arrangements were not included in the table above as they are a function of the power generated by the related solar energy systems in the future.
	Included in revenue for the years ended December 31, 2014, 2013 and 2012 was $79.5 million, $42.0 million and $20.2 million, respectively, that were accounted for as contingent rentals. The contingent rentals comprised of customer payments under power purchase agreements and performance-based incentives received or receivable by the Company from various utility companies.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Inventories	6. Inventories
	Inventories consisted of the following (in thousands):
		As of December 31,
		2014		2013
	Raw materials	$	209,251	$	105,919
	Work in progress		7,972		5,475
	Total	$	217,223	$	111,394
	Raw materials are comprised of component parts that include silicon wafers, process gasses, chemicals and other consumables used in solar cell production, solar cells, photovoltaic panels, inverters, mounting hardware and miscellaneous electrical components that will be deployed to either solar energy systems that will be sold or solar energy systems that will be leased. Work in progress is comprised of installations in progress and includes component parts, labor and other overhead costs incurred up to the balance sheet date on solar energy systems that will be sold and for which binding sales contracts have already been executed. For solar energy systems, leased and to be leased, the Company commences transferring component parts from inventory to construction in progress, a component of solar energy systems, leased and to be leased, once a lease contract with a customer has been executed and installation has initiated. Additional costs incurred on the leased systems, including labor and overhead, are recorded within construction in progress. As of December 31, 2014 and 2013, inventory reserves were $3.1 million and $1.4 million, respectively, and are included in the table above under raw materials.

Solar_Energy_Systems_Leased_an

Solar Energy Systems, Leased and To Be Leased - Net	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Solar Energy Systems, Leased and To Be Leased - Net	7. Solar Energy Systems, Leased and To Be Leased – Net
	Solar energy systems, leased and to be leased – net consisted of the following (in thousands):
		As of December 31,
		2014			2013
	Solar energy systems leased to customers	$	2,388,548		$	1,513,731
	Initial direct costs related to customer solar energy		207,537			94,321
	system lease acquisition costs
			2,596,085			1,608,052
	Less accumulated depreciation and amortization		(159,160	)		(86,457	)
			2,436,925			1,521,595
	Solar energy systems under construction		131,048			53,010
	Solar energy systems to be leased to customers		228,823			107,916
	Solar energy systems, leased and to be leased - net	$	2,796,796		$	1,682,521
	Included under solar energy systems leased to customers as of December 31, 2014 and 2013 was $66.4 million related to capital leased assets, with an accumulated depreciation of $7.9 million and $5.3 million, respectively. As of December 31, 2014, future minimum lease payments to the lessor under this lease arrangement for each of the next five years and thereafter were as follows (in thousands):
	2015	$	2,327
	2016		2,339
	2017		2,353
	2018		2,367
	2019		2,383
	Thereafter		21,072
	Total	$	32,841
	As of December 31, 2014, future minimum lease receipts to be paid to the Company by sub-lessees under this lease arrangement for each of the next five years and thereafter were as follows (in thousands):
	2015	$	2,428
	2016		2,451
	2017		2,480
	2018		2,511
	2019		2,542
	Thereafter		34,273
	Total	$	46,685
	The amounts in the table above are also included as part of the noncancelable operating lease payments from customers disclosed in Note 5, Noncancelable Operating Lease Payments Receivable.

Property_Plant_and_Equipment_N

Property Plant and Equipment - Net	12 Months Ended
	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Property Plant and Equipment - Net	8. Property, Plant and Equipment – Net
	Property, plant and equipment consisted of the following (in thousands):
		As of December 31,
		2014			2013
	Vehicles	$	28,815		$	23,548
	Computer hardware and software		28,724			7,381
	Furniture and fixtures		5,501			2,653
	Leasehold improvements		13,992			7,397
	Build-to-suit lease asset under construction		26,450			—
	Manufacturing and lab equipment		21,677			—
	Buildings		4,288			—
	Land and land use rights		2,423			—
	Other		569			167
			132,439			41,146
	Less accumulated depreciation and amortization		(30,525	)		(18,739	)
	Property, plant and equipment - net	$	101,914		$	22,407
	Build-to-suit lease asset under construction relates to costs incurred to date under the build-to-suit lease arrangement discussed in Note 22, Commitments and Contingencies.

Accrued_and_Other_Current_Liab

Accrued and Other Current Liabilities	12 Months Ended
	Dec. 31, 2014
Payables And Accruals [Abstract]
Accrued and Other Current Liabilities	9. Accrued and Other Current Liabilities
	Accrued and other current liabilities consisted of the following (in thousands):
		As of December 31,
		2014		2013
	Accrued compensation	$	50,414	$	21,634
	Current portion of contingent consideration		41,978		—
	Accrued expenses		27,485		19,943
	Accrued sales and use taxes		10,438		5,229
	Accrued warranty		8,607		7,502
	Accrued professional services fees		6,813		4,031
	Current portion of capital lease obligation		3,430		1,555
	Current portion of deferred gain on sale-leaseback		3,243		3,243
	transactions
	Amounts refundable to an investor		—		5,699
	Income taxes payable		—		1,577
	Current portion of participation interest		—		1,744
	Total	$	152,408	$	72,157
	The amounts refundable to an investor at December 31, 2013 represented the portion of cash received from an investor for the monetization of ITCs that were related to assets not yet placed in service as of that date. The Company refunded the entire amount to the investor in the first quarter of 2014. The current portion of contingent consideration is related to the Company’s acquisition of Silevo in the third quarter of 2014 (see Note 3, Acquisitions).

Other_Liabilities_and_Defereed

Other Liabilities and Defereed Credits	12 Months Ended
	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Other Liabilities and Deferred Credits	10. Other Liabilities and Deferred Credits
	Other liabilities and deferred credits consisted of the following (in thousands):
		As of December 31,
		2014		2013
	Deferred gain on sale-leaseback transactions, net of current	$	54,790	$	58,033
	portion
	Build-to-suit lease liability		26,450		—
	Deferred rent expense		4,838		3,333
	Capital lease obligation		27,791		27,126
	Liability for receipts from an investor		3,213		72,520
	Contingent consideration		75,219		—
	Participation interest		15,556		14,114
	Other noncurrent liabilities		36,617		18,313
	Total	$	244,474	$	193,439
	The liability for receipts from an investor represents amounts received from an investor under a lease pass-through fund arrangement for monetization of ITCs for assets not yet placed in service. This amount is reclassified to deferred revenue when the assets are placed in service.
	The participation interest represents rights granted by the Company to a former investor to share in the future residual returns from securitized solar energy systems as part of the compensation for the termination of a lease pass-through fund arrangement, as described in Note 11, Indebtedness.
	The contingent consideration is related to the Company’s acquisition of Silevo in the third quarter of 2014 (see Note 3, Acquisitions).

Indebtedness

Indebtedness	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Indebtedness	11. Indebtedness
	The following is a summary of the Company’s debt as of December 31, 2014 (dollars in thousands):
				Carrying Value, Net
				of Fees
		Unpaid						Unused
		Principal						Borrowing
		Balance		Current		Long-Term		Capacity		Interest Rate	Maturity Dates
	Recourse debt:
	Revolving credit facility	$	130,000	$	—	$	126,939	$	54,935	3.40%	December 2016
	Vehicle loans		9,724		2,647		7,077		—	1.9%-7.5%	March 2015 -
											June 2019
	2.75% Convertible senior notes due in 2018		230,000		—		230,000		—	2.80%	November 2018
	1.625% Convertible senior notes due in 2019		566,000		—		566,000		—	1.60%	November 2019
	Solar Bonds		3,943		1,150		2,793		—	2.0%-4.0%	October 2015 -
											October 2018
	Total recourse debt		939,667		3,797		932,809		54,935
	Non-recourse debt:
	Term loan assumed from Silevo acquisition		9,134		9,134		—		—	7.80%	June 2015
	Term loan due in May 2016		34,195		—		33,497		90,805	3.20%	May 2016
	Term loan due in December 2016		122,655		—		120,108		127,345	3.4%-3.5%	December 2016
	Solar Asset-backed Notes, Series 2013-1		49,519		3,291		46,228		—	4.80%	November 2038
	Solar Asset-backed Notes, Series 2014-1		67,676		2,779		64,897		—	4.60%	Apr-44
	Solar Asset-backed Notes, Series 2014-2		201,494		7,504		193,268		—	4.0%-Class A	Jul-44
										5.4%-Class B
	Total non-recourse debt		484,673		22,708		457,998		218,150
	Total debt	$	1,424,340	$	26,505	$	1,390,807	$	273,085
	The following is a summary of the Company’s debt as of December 31, 2013 (dollars in thousands):
				Carrying Value, Net
				of Fees
		Unpaid						Unused
		Principal						Borrowing
		Balance		Current		Long-Term		Capacity		Interest Rate	Maturity Date
	Recourse debt:
	Revolving credit facility	$	142,531	$	—	$	138,535	$	54,776	3.4%-5.5%	December 2016
	Vehicle loans		6,517		1,789		4,728		—	0.0%-7.5%	March 2015 -
											December 2018
	2.75% Convertible senior notes due in 2018		230,000		—		230,000		—	2.80%	November 2018
	Total recourse debt		379,048		1,789		373,263		54,776
	Non-recourse debt:
	Working capital financing		9,990		1,197		8,793		—	5.5%-5.6%	December 2024
	Credit facility for SolarStrong		5,733		149		5,297		344,000	6.8%-7.3%	June 2032 -
											December 2032
	Term loan due in June 2015		87,891		4,192		81,259		12,109	3.4%-3.7%	June 2015
	Solar Asset-backed Notes, Series 2013-1		52,935		3,155		49,780		—	4.80%	November 2038
	Total non-recourse debt		156,549		8,693		145,129		356,109
	Other debt		95		95		—		—
	Total debt	$	535,692	$	10,577	$	518,392	$	410,885
	Recourse debt refers to debt that is recourse to the Company’s general assets. Non-recourse debt refers to debt that is recourse to only specified assets or subsidiaries of the Company. The Company’s debt is described further below.
	Recourse Debt Facilities:
	Revolving Credit Facility
	In September 2012, the Company entered into a revolving credit agreement with a syndicate of banks to obtain funding for working capital, letters of credit and funding for general corporate needs. The committed amount under the revolving credit facility was increased from $75.0 million to $200.0 million in 2013. Borrowed funds bear interest, at the Company’s option, at an annual rate of (a) 3.25% plus LIBOR or (b) 2.25% plus the highest of (i) the federal funds rate plus 0.50%, (ii) Bank of America’s published “prime rate” or (iii) LIBOR plus 1.00%. The fee for undrawn commitments is 0.375% per annum. The revolving credit facility is secured by certain of the Company’s machinery and equipment, accounts receivable, inventory and other assets. In each of June, July, September, October and December 2014, the revolving credit facility was amended to increase certain debt covenant thresholds, including those related to permitted investment amounts and capital expenditures by the Company, to make certain changes in connection with the Company’s acquisition of Silevo and to make certain changes in connection with the issuance and payment of certain loans and debt, among other things. The Company was in compliance with all debt covenants as of December 31, 2014.
	Vehicle Loans
	The Company has entered into various vehicle loan agreements with various financial institutions. The vehicle loans are secured by the vehicles financed. The Company was in compliance with all debt covenants as of December 31, 2014.
	2.75% Convertible Senior Notes Due in 2018
	In October 2013, the Company issued $230.0 million in aggregate principal of 2.75% convertible senior notes due on November 1, 2018 through a public offering. The net proceeds from the offering, after deducting transaction costs, were $222.5 million. The Company debt issuance costs were recorded in other assets and are being amortized to interest expense over the contractual term of the convertible senior notes.
	Each $1,000 of principal of the convertible senior notes is initially convertible into 16.2165 shares of the Company’s common stock, which is equivalent to an initial conversion price of $61.67 per share, subject to adjustment upon the occurrence of specified events set forth in the applicable indenture. Holders of the convertible senior notes may convert their convertible senior notes at their option at any time up to and including the second scheduled trading day prior to maturity. If certain events that would constitute a make-whole fundamental change under the applicable indenture occur prior to the maturity date, the Company would increase the conversion rate for a holder who elects to convert its convertible senior notes in connection with such an event in certain circumstances. The maximum conversion rate is capped at 21.4868 shares for each $1,000 of principal of the convertible senior notes, which is equivalent to a minimum conversion price of $46.54 per share. The convertible senior notes do not have a cash conversion option. The convertible senior note holders may require the Company to repurchase their convertible senior notes for cash only under certain defined fundamental changes. The Company was in compliance with all debt covenants as of December 31, 2014.
	1.625% Convertible Senior Notes Due in 2019
	In September 2014, the Company issued $500.0 million in aggregate principal of 1.625% convertible senior notes due on November 1, 2019 through a private placement. The net amount from the issuance, after deducting transaction costs, was $488.3 million. On October 10, 2014, the Company issued an additional $66.0 million in aggregate principal of the 1.625% convertible senior notes, pursuant to the exercise of an option by the initial purchasers. The net amount from the additional issuance, after deducting transaction costs, was $64.5 million. The debt issuance costs were recorded in other assets and are being amortized to interest expense over the contractual term of the convertible senior notes.
	Each $1,000 of principal of the convertible senior notes is initially convertible into 11.972 shares of the Company’s common stock, which is equivalent to an initial conversion price of $83.53 per share, subject to adjustment upon the occurrence of specified events set forth in the applicable indenture. Holders of the convertible senior notes may convert their convertible senior notes at their option at any time up to and including the second scheduled trading day prior to maturity. If certain events that would constitute a make-whole fundamental change under the applicable indenture occur prior to the maturity date, the Company would increase the conversion rate for a holder who elects to convert its convertible senior notes in connection with such an event in certain circumstances. The maximum conversion rate is capped at 15.8629 shares for each $1,000 of principal of the convertible senior notes, which is equivalent to a minimum conversion price of $63.04 per share. The convertible senior notes do not have a cash conversion option. The convertible senior note holders may require the Company to repurchase their convertible senior notes for cash only under certain defined fundamental changes. The Company was in compliance with all debt covenants as of December 31, 2014.
	In connection with the issuance of the convertible senior notes in September 2014, the Company paid $57.6 million to enter into capped call option agreements to reduce the potential dilution to holders of the Company’s common stock upon conversion of the convertible senior notes. In connection with the additional issuance of the convertible senior notes on October 10, 2014, the Company paid $7.6 million to enter into an additional capped call option agreement. The capped call option agreements have a cap price of $126.08 and an initial strike price of $83.53, which is equal to the initial conversion price of the convertible senior notes. The capped call options expire on various dates ranging from September 4, 2019 to October 29, 2019. The capped call option agreements are separate transactions, are not a part of the terms of the convertible senior notes and do not affect the rights of the convertible senior note holders. The capped call option agreements met the criteria for equity classification and were recorded as reductions to additional paid-in capital. The capped call option agreements are excluded from the calculation of diluted net income (loss) per share attributable to common stockholders as their effect is antidilutive.
	Solar Bonds
	In October 2014, the Company commenced issuing Solar Bonds to the general public, which are senior unsecured obligations that are structurally subordinate to the indebtedness and other liabilities of the Company’s subsidiaries. The Company has offered Solar Bonds with terms ranging from one to seven years and interest rates ranging from 2.00% to 4.00% per annum. The Company intends to continue to issue Solar Bonds periodically. The Company was in compliance with all debt covenants as of December 31, 2014.
	Non-Recourse Debt Facilities:
	Term Loan Assumed From Silevo Acquisition
Through the Silevo acquisition, the Company assumed a pre-existing term loan with an outstanding principal balance of $9.1 million. The term loan bears interest at a fixed rate of 7.8% per annum and is denominated in the Chinese Yuan. The term loan is a liability of the Silevo JV only and is non-recourse to Company and its other subsidiaries. The Company was in compliance with all debt covenants as of December 31, 2014.
Term Loan Due in May 2016
On May 23, 2014, a subsidiary of the Company entered into an agreement with a syndicate of banks for a term loan of $125.0 million. The term loan bears interest at an annual rate of 3.00% to 4.00%, depending on the cumulative period the term loan has been outstanding, plus LIBOR or, at the Company’s option, plus the highest of (i) the Federal Funds Rate plus 0.50%, (ii) Bank of America’s published “prime rate” or (iii) LIBOR plus 1.00%. The term loan is secured by certain assets and cash flows of the subsidiary and is non-recourse to the Company’s other assets or cash flows. The Company was in compliance with all debt covenants as of December 31, 2014.
Term Loan Due in December 2016
On February 4, 2014, a subsidiary of the Company entered into an agreement with a syndicate of banks for a term loan of $100.0 million. On February 20, 2014, the agreement was amended to increase the maximum term loan availability to $220.0 million. On March 20, 2014, the agreement was further amended to increase the maximum term loan availability to $250.0 million. The term loan bears interest at an annual rate of LIBOR plus 3.25% or, at the Company’s option, 3.25% plus the highest of (i) the Federal Funds Rate plus 0.50%, (ii) Bank of America’s published “prime rate” or (iii) LIBOR plus 1.00%. The term loan is secured by the assets and cash flows of the subsidiary and is non-recourse to the Company’s other assets. The Company was in compliance with all debt covenants as of December 31, 2014.
Solar Asset-backed Notes, Series 2013-1
The Company has structured and entered into various solar asset-backed note securitization transactions pursuant to its financial strategy of monetizing solar assets at the lowest cost of capital.
In November 2013, the Company pooled and transferred qualifying solar energy systems and the associated customer contracts into a special purpose entity, or SPE, and issued $54.4 million in aggregate principal of Solar Asset-backed Notes, Series 2013-1, backed by these solar assets to certain investors. The SPE is wholly owned by the Company and is consolidated in the Company’s financial statements. Accordingly, the Company did not recognize a gain or loss on the transfer of these solar assets. As of December 31, 2014, these solar assets had a carrying value of $143.9 million and are included under solar energy systems, leased and to be leased — net, in the consolidated balance sheets. The Solar Asset-backed Notes were issued at a discount of 0.05%. The cash flows generated by these solar assets are used to service the monthly principal and interest payments on the Solar Asset-backed Notes and satisfy the SPE’s expenses, and any remaining cash is distributed to a wholly owned subsidiary of the Company. The Company recognizes revenue earned from the associated customer contracts in accordance with the Company’s revenue recognition policy. The assets and cash flows generated by the qualifying solar energy systems are not available to the other creditors of the Company, and the creditors of the SPE, including the Solar Asset-backed Note holders, have no recourse to the Company’s other assets. The Company contracted with the SPE to provide operations and maintenance and administrative services for the qualifying solar energy systems. The Company was in compliance with all debt covenants as of December 31, 2014.
In connection with the pooling of the assets that were transferred to the SPE in November 2013, the Company terminated a lease pass-through arrangement with an investor. The lease pass-through arrangement had been accounted for as a borrowing and any amounts outstanding from the lease pass-through arrangement were recorded as a lease pass-through financing obligation. The balance that was then outstanding from the lease pass-through arrangement was $56.4 million. The Company paid the investor an aggregate of $40.2 million, and the remaining balance is to be paid over time. The remaining balance is paid using the net cash flows generated by the same assets previously leased under the lease pass-through arrangement, after payment of the principal and interest on the Solar Asset-backed Notes and expenses related to the assets and the Notes, including asset management fees, custodial fees and trustee fees, and was contractually documented as a right to participate in future cash flows of the SPE. This right to participate in future residual cash flows generated by the assets of the SPE has been disclosed as a component of other liabilities and deferred credits for the noncurrent portion and as a component of accrued and other current liabilities for the current portion under the caption “participation interest.” The Company accounted for the participation interest as a liability because the investor has no voting or management rights in the SPE, the participation interest would terminate upon the investor achieving a specified return and the investor has the option to put the participation interest to the Company on a specified date for the amount necessary for the investor to achieve the specified return, which would require the Company to settle the participation interest in cash. In addition, under the terms of the participation interest, the Company has the option to purchase the participation interest from the investor for the amount necessary for the investor to achieve the specified return.
Solar Asset-backed Notes, 2014-1
In April 2014, the Company pooled and transferred qualifying solar energy systems and the associated customer contracts into a SPE and issued $70.2 million in aggregate principal of Solar Asset-backed Notes, Series 2014-1, backed by these solar assets to certain investors. The SPE is wholly owned by the Company and is consolidated in the Company’s financial statements. Accordingly, the Company did not recognize a gain or loss on the transfer of these solar assets. As of December 31, 2014, these solar assets had a carrying value of $134.4 million and are included under solar energy systems, leased and to be leased — net, in the consolidated balance sheets. The Solar Asset-backed Notes were issued at a discount of 0.01%. The cash flows generated by these solar assets are used to service the monthly principal and interest payments on the Solar Asset-backed Notes and satisfy the SPE’s expenses, and any remaining cash is distributed to a wholly owned subsidiary of the Company. The Company recognizes revenue earned from the associated customer contracts in accordance with the Company’s revenue recognition policy. The assets and cash flows generated by the qualifying solar energy systems are not available to the other creditors of the Company, and the creditors of the SPE, including the Solar Asset-backed Note holders, have no recourse to the Company’s other assets. The Company contracted with the SPE to provide operations and maintenance and administrative services for the qualifying solar energy systems. The Company was in compliance with all debt covenants as of December 31, 2014.
In connection with the transfer of the assets into the SPE in April 2014, the Company terminated a lease pass-through arrangement with an entity that is a partnership between the Company and an investor. The partnership is a VIE that is consolidated by the Company as the primary beneficiary. To settle the associated lease pass-through financing obligation, the partnership distributed $74.5 million to the investor, including amounts previously accrued for distribution, and amended the expected future distributions to the investor. Additionally, the contractual documents of the partnership were amended to grant the investor the right to put its interest in the partnership back to the partnership. Accordingly, the carrying value of the investor’s interest in the partnership was reclassified from noncontrolling interests in subsidiaries to redeemable noncontrolling interests in subsidiaries in the consolidated balance sheets.
Solar Asset-backed Notes, Series 2014-2
In July 2014, the Company pooled and transferred qualifying solar energy systems and the associated customer contracts into a SPE and issued $160.0 million in aggregate principal of Solar Asset-backed Notes, Series 2014-2, Class A, and $41.5 million in aggregate principal of Solar Asset-backed Notes, Series 2014-2, Class B, to certain investors. The SPE is wholly owned by the Company and is consolidated in the Company’s financial statements. Accordingly, the Company did not recognize a gain or loss on the transfer of these solar assets. As of December 31, 2014, these solar assets had a carrying value of $285.6 million and are included under solar energy systems, leased and to be leased — net, in the consolidated balance sheets. The Solar Asset-backed Notes were issued at a discount of 0.01%. These solar assets and the associated customer contracts are leased to an investor under a lease pass-through arrangement that the Company has accounted for as a borrowing. The rent paid by the investor under the lease pass-through arrangement is used (and, following the expiration of the lease pass-through arrangement, the cash generated by these solar assets will be used) to service the monthly principal and interest payments on the Solar Asset-backed Notes and satisfy the SPE’s expenses, and any remaining cash is distributed to a wholly owned subsidiary of the Company. The Company recognizes revenue earned from the associated customer contracts in accordance with the Company’s revenue recognition policy. The assets and cash flows generated by these solar assets are not available to the other creditors of the Company, and the creditors of the SPE, including the Solar Asset-backed Note holders, have no recourse to the Company’s other assets. The Company contracted with the SPE to provide operations and maintenance and administrative services for the qualifying solar energy systems. The Company was in compliance with all debt covenants as of December 31, 2014.
In connection with the transfer of the assets into the SPE in July 2014, the Company paid $129.3 million to fully settle the term loan obtained on June 7, 2013 that was due in June 2015, as noted below.
Working Capital Financing
On May 26, 2010, a subsidiary of the Company entered into a financing agreement with a bank to obtain funding for working capital. The amount available to be borrowed under the financing agreement was determined based on the present value of expected future lease receipts from solar energy systems owned by the subsidiary and leased to customers, up to a maximum of $16.3 million. The working capital financing was funded in four tranches and was available for draw-down through March 31, 2011. Each tranche bore interest at an annual rate of 2.00% plus the swap rate applicable to the average life of the scheduled lease receipts for the tranche. The working capital financing was secured by substantially all of the subsidiary’s assets and was nonrecourse to the Company’s other assets. On July 2, 2014, the Company fully repaid the outstanding balance of and terminated the working capital financing, recognizing a loss on debt extinguishment of $0.4 million within other expense – net in the consolidated statements of operations.
Credit Facility for SolarStrong
On November 21, 2011, a subsidiary of the Company entered into an agreement with a bank for a credit facility of up to $350.0 million. The credit facility was to be used to partially fund the Company’s SolarStrong initiative, which was a five-year plan to build solar energy systems for privatized U.S. military housing communities across the country. The credit facility was to be drawn-down in tranches, with the interest rates determined when the amounts were drawn-down. The credit facility was secured by the assets of the SolarStrong initiative and was non-recourse to the Company’s other assets. On December 24, 2014, the Company paid $5.5 million to fully settle the outstanding balance of and terminate the credit facility due to the unfavorable financing economics of this facility. As a result, the Company recognized a loss on debt extinguishment of $2.6 million within other expense – net in the consolidated statements of operations.
Term Loan Due in June 2015
On June 7, 2013, a subsidiary of the Company entered into an agreement with a syndicate of banks for a term loan of $100.0 million. On January 6, 2014, the agreement was amended to increase the maximum term loan availability to $158.0 million. Each tranche of the term loan bore interest at an annual rate of LIBOR plus 3.25%. The term loan was secured by the assets and cash flows of the subsidiary and was non-recourse to the Company’s other assets. On July 31, 2014, the Company fully repaid the outstanding balance of and terminated the term loan in connection with the issuance of Solar Asset-backed Notes, Series 2014-2, as described above. Upon the termination of this facility, the Company recognized a loss on debt extinguishment of $1.5 million within other expense – net in the consolidated statements of operations.
Schedule of Principal Maturities of Debt
The future scheduled principal maturities of debt as of December 31, 2014 were as follows (in thousands):
	Recourse Debt
	Excluding
	Convertible		Non-Recourse		Convertible
	Senior Notes		Debt		Senior Notes		Total
2015	$	3,787	$	22,733	$	—	$	26,520
2016		133,137		169,855		—		302,992
2017		3,442		13,609		—		17,051
2018		2,876		13,892		230,000		246,768
2019		425		14,474		566,000		580,899
Thereafter		—		250,110		—		250,110
Total	$	143,667	$	484,673	$	796,000	$	1,424,340
The convertible senior notes do not have a cash conversion option and are therefore expected to be settled in shares of the Company’s common stock.

VIE_Fund_Arrangements

VIE Fund Arrangements	12 Months Ended
	Dec. 31, 2014
Variable Interest Entity Disclosure [Abstract]
VIE Fund Arrangements	12. VIE Fund Arrangements
	The Company has entered into various arrangements with investors to facilitate funding and monetization of solar energy systems. These arrangements include those described in this Note 12, VIE Fund Arrangements, as well as those described in Note 13, Lease Pass-through Financing Obligation, Note 14, Sale-Leaseback Arrangements, and Note 15, Sale-Leaseback Financing Obligation.
	Wholly owned subsidiaries of the Company and fund investors formed and contributed cash or assets to various solar financing funds and entered into related agreements. Additionally, the Company acquired the assets of a fund through a business combination in September 2013 and assumed the related contractual arrangements. As of December 31, 2014, the fund investors had contributed $1,683.0 million into the funds. The table below shows the number of funds by type of investor and the carrying value of solar energy systems in the funds:
				Carrying
				Value of
	Investor	Number		Solar Energy
	Classifcation	of Funds		Systems
	Financial institutions		16	$	1,174,120
	Corporations		5		148,931
	Utilities		2		252,836
	Various other investors		1		5,572
	Total		24	$	1,581,459
	The Company has determined that the funds are VIEs and it is the primary beneficiary of these VIEs by reference to the power and benefits criterion under ASC 810, Consolidation. The Company has considered the provisions within the contractual agreements, which grant it power to manage and make decisions that affect the operation of these VIEs, including determining the solar energy systems and associated customer contracts to be sold or contributed to these VIEs and the redeployment of solar energy systems. The Company considers that the rights granted to the fund investors under the contractual agreements are more protective in nature rather than participating.
	As the primary beneficiary of these VIEs, the Company consolidates in its financial statements the financial position, results of operations and cash flows of these VIEs, and all intercompany balances and transactions between the Company and these VIEs are eliminated in the consolidated financial statements.
	Cash distributions of income and other receipts by a fund, net of agreed upon expenses, estimated expenses, tax benefits and detriments of income and loss and tax credits, are allocated to the fund investor and the Company’s subsidiary as specified in contractual agreements.
	Generally, the Company’s subsidiary has the option to acquire the fund investor’s interest in the fund for an amount based on the market value of the fund or the formula specified in the contractual agreements.
	On March 31, 2014, the Company acquired a fund investor’s interest in one fund for total consideration of $0.5 million.
	As of December 31, 2014 and 2013, the Company was contractually required to make payments to a fund investor in order to ensure the investor is projected to achieve a specified minimum return annually. The amounts of any potential future payments under this guarantee are dependent on the amounts and timing of future distributions to the investor from the fund, the tax benefits that accrue to the investor from the fund’s activities and the amount and timing of the Company’s purchase of the investor’s interest in the fund or the amount and timing of the distributions to the investor upon liquidation of the fund. Due to uncertainties associated with estimating the amount and timing of distributions to the investor and the possibility and timing of the liquidation of the fund, the Company is unable to determine the potential maximum future payments that it would have to make under this guarantee.
	Upon the sale or liquidation of a fund, distributions would occur in the order and priority specified in the contractual agreements.
	Pursuant to management services, maintenance and warranty arrangements, the Company has been contracted to provide services to the funds, such as operations and maintenance support, accounting, lease servicing and performance reporting. In some instances, the Company has guaranteed payments to the investors as specified in the contractual agreements. A fund’s creditors have no recourse to the general credit of the Company or to that of other funds. None of the assets of the funds had been pledged as collateral for their obligations.
	The Company presents the solar energy systems in the VIEs under solar energy systems, leased and to be leased – net in the consolidated balance sheets. The aggregate carrying values of the VIEs’ assets and liabilities, after elimination of intercompany transactions and balances, in the consolidated balance sheets were as follows (in thousands):
		As of December 31,
		2014		2013
	Assets
	Current assets:
	Cash and cash equivalents	$	26,419	$	35,141
	Restricted cash		106		115
	Accounts receivable - net		6,769		4,802
	Rebates receivable		25,397		17,351
	Prepaid expenses and other current assets		615		3,831
	Total current assets		59,306		61,240
	Restricted cash		300		—
	Solar energy systems, leased and to be leased - net		1,581,459		759,148
	Other assets		3,780		2,777
	Total assets	$	1,644,845	$	823,165
	Liabilities
	Current liabilities:
	Distributions payable to noncontrolling interests and	$	8,552	$	20,390
	redeemable noncontrolling interests
	Current portion of deferred U.S. Treasury grant income		6,502		6,668
	Accrued and other current liabilities		336		615
	Customer deposits		6,405		5,291
	Current portion of deferred revenue		16,746		13,754
	Current portion of bank borrowings		—		251
	Total current liabilities		38,541		46,969
	Deferred revenue, net of current portion		256,200		206,324
	Bank borrowings, net of current portion		—		5,482
	Deferred U.S. Treasury grant income, net of current portion		170,548		180,566
	Other liabilities and deferred credits		10,825		1,893
	Total liabilities	$	476,114	$	441,234
	The Company is contractually obligated to make certain fund investors whole for losses that they may suffer in certain limited circumstances resulting from the disallowance or recapture of ITCs or U.S. Treasury grants, including in the event that the U.S. Treasury Department awards ITCs or U.S. Treasury grants for the solar energy systems in the funds that are less than the amounts initially anticipated. The Company accounts for distributions due to the fund investors arising from a reduction of anticipated ITCs or U.S. Treasury grants received under distributions payable to noncontrolling interests and redeemable noncontrolling interests in the consolidated balance sheets. As of December 31, 2014, the Company had accrued $2.7 million for this obligation.

Lease_PassThrough_Financing_Ob

Lease Pass-Through Financing Obligation	12 Months Ended
	Dec. 31, 2014
Lease Pass Through Financing Obligation [Abstract]
Lease Pass-Through Financing Obligation	13. Lease Pass-Through Financing Obligation
	Through December 31, 2014, the Company had entered into eight transactions referred to as “lease pass-through fund arrangements.” Under these arrangements, the Company’s wholly owned subsidiaries finance the cost of solar energy systems with investors through arrangements contractually structured as master leases for an initial term ranging between 10 and 25 years. These solar energy systems are subject to lease or power purchase agreements with customers with an initial term not exceeding 20 years. These solar energy systems are included under solar energy systems, leased and to be leased – net in the consolidated balance sheets. As discussed in Note 11, Indebtedness, in November 2013, in connection with the Company pooling assets for purposes of issuing Solar Asset-backed Notes, the Company terminated a lease pass-through fund arrangement with an investor. The cost of the solar energy systems under the lease pass-through fund arrangements as of December 31, 2014 and 2013 was $540.0 million and $420.4 million, respectively. The accumulated depreciation related to these assets as of December 31, 2014 and 2013 was $34.1 million and $17.6 million, respectively. The total lease pass-through financing obligation as of December 31, 2014 and 2013 was $88.7 million and $93.2 million, respectively, of which $29.2 million and $29.0 million, respectively, was classified as current liabilities.
	The investors make a large upfront payment to the lessor, which is a subsidiary of the Company, and in some cases, subsequent smaller quarterly payments. The Company accounts for the payments received from the investors under the lease pass-through fund arrangements, net of amounts allocated to ITCs revenue, where applicable, as a borrowing by recording the proceeds received as a lease pass-through financing obligation, which would be repaid from U.S. Treasury grants (where applicable), customer payments and incentive rebates that would be received by the investors. Under this approach, the Company continues to account for the arrangement with the customers in its consolidated financial statements, whether the cash generated from the customer arrangements is received by the Company or paid directly to the investors. A portion of the amounts received by the investors from U.S. Treasury grants (where applicable), customer payments and incentive rebates associated with the leases assigned to the investors is applied to reduce the lease pass-through financing obligation, and the balance is allocated to interest expense. The incentive rebates and host customer payments are recognized into revenue consistent with the Company’s revenue recognition accounting policy. The U.S. Treasury grants are initially recorded as deferred U.S. Treasury grants income and subsequently recognized as a reduction to the depreciation expense, consistent with the Company’s accounting policy for recognition of U.S. Treasury grant income. 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 an 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. The lease pass-through financing obligation is nonrecourse once the associated assets have been placed in service and all the customer arrangements have been assigned to the investors.
	As of December 31, 2014, the future minimum lease payments to be received from the investors under the lease pass-through fund arrangements for each of the next five years and thereafter were as follows (in thousands):
	2015	$	24,216
	2016		23,857
	2017		23,989
	2018		24,070
	2019		24,023
	Thereafter		76,468
	Total	$	196,623
	For two of the lease pass-through fund arrangements, the Company’s subsidiaries have pledged its assets to the investors as security for their obligations under the contractual agreements.
	For each of the lease pass-through fund arrangements, the Company is required to comply with certain financial covenants specified in the contractual agreements, which the Company had met as of December 31, 2014.
	Under the lease pass-through fund arrangements, the Company’s subsidiaries are responsible for services such as warranty support, accounting, lease servicing and performance reporting. The performance of the obligations of the Company’s subsidiaries is guaranteed by the Company. As part of the warranty and performance guarantee with host customers, the Company guarantees certain specified minimum annual solar energy production output for the solar energy systems leased to the customers.
	Under the lease pass-through fund arrangements, there is a one-time future lease payment reset mechanism that is set to occur after all of the solar energy systems are delivered and placed in service in a fund. This reset date occurs when the installed capacity of the solar energy systems and in service placement dates are known or on an agreed upon date. As part of this reset process, the lease prepayment will be updated to reflect certain specified conditions as they exist at such date, including the ultimate system size of the equipment that was leased, how much it cost and when it went into service. As a result of this reset, the Company may be obligated to refund a portion of an investor’s lease prepayments or may be entitled to receive an additional lease prepayment from the investor. Additional payments by the investor would be recorded as additional lease pass-through financing obligation, while refunds of lease prepayments would reduce the lease pass-through financing obligation.

SaleLeaseback_Arrangements

Sale-Leaseback Arrangements	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Sale-Leaseback Arrangements	14. Sale-Leaseback Arrangements
	In 2010, the Company executed a sale-leaseback arrangement with an existing investor, under which a wholly owned subsidiary of the Company entered into a 15-year master leaseback arrangement. The assets sold to the investor were valued at $25.2 million. The Company’s subsidiary leased the solar energy systems to end-user customers. The obligations of the Company’s subsidiary to the investor for this arrangement together with a funding arrangement entered into in 2009 with the same investor are guaranteed by the Company and supported by a $1.25 million restricted cash escrow. The amount in escrow is reduced by $0.25 million per annum in each of the first four years commencing in 2010, and the remaining balance remains in place until the end of the master lease period. Under this arrangement, the Company’s subsidiary is responsible for services such as warranty support, accounting, lease servicing and performance reporting.
	As of December 31, 2014 and 2013, the Company had contributed assets with a cost of $44.6 million to its wholly owned subsidiary that in turn sold the assets to a new investor and then executed a 15-year master leaseback agreement with the investor. Under this arrangement, the tax benefits from ITCs or Treasury grants in lieu of tax credits inure to the investor as the owner of the assets. A total of $100 million in financing was available from the investor under this fund arrangement in the form of proceeds from the sale of the assets, which had been utilized by December 31, 2014.
	The Company has committed to make investors that have executed sale-leaseback arrangements with the Company whole for any reductions in the tax credit or U.S. Treasury awards resulting from changes in the tax basis submitted. The Company accrues any such payments due to these investors. As of December 31, 2014, no such amounts were due to these investors.
	The Company has accounted for these sale-leaseback arrangements in accordance with the Company’s accounting policy as described in Note 2, Summary of Significant Accounting Policies and Procedures.

SaleLeaseback_Financing_Obliga

Sale-Leaseback Financing Obligation	12 Months Ended
	Dec. 31, 2014
Sale Leaseback Transaction [Line Items]
Sale-Leaseback Arrangements	14. Sale-Leaseback Arrangements
	In 2010, the Company executed a sale-leaseback arrangement with an existing investor, under which a wholly owned subsidiary of the Company entered into a 15-year master leaseback arrangement. The assets sold to the investor were valued at $25.2 million. The Company’s subsidiary leased the solar energy systems to end-user customers. The obligations of the Company’s subsidiary to the investor for this arrangement together with a funding arrangement entered into in 2009 with the same investor are guaranteed by the Company and supported by a $1.25 million restricted cash escrow. The amount in escrow is reduced by $0.25 million per annum in each of the first four years commencing in 2010, and the remaining balance remains in place until the end of the master lease period. Under this arrangement, the Company’s subsidiary is responsible for services such as warranty support, accounting, lease servicing and performance reporting.
	As of December 31, 2014 and 2013, the Company had contributed assets with a cost of $44.6 million to its wholly owned subsidiary that in turn sold the assets to a new investor and then executed a 15-year master leaseback agreement with the investor. Under this arrangement, the tax benefits from ITCs or Treasury grants in lieu of tax credits inure to the investor as the owner of the assets. A total of $100 million in financing was available from the investor under this fund arrangement in the form of proceeds from the sale of the assets, which had been utilized by December 31, 2014.
	The Company has committed to make investors that have executed sale-leaseback arrangements with the Company whole for any reductions in the tax credit or U.S. Treasury awards resulting from changes in the tax basis submitted. The Company accrues any such payments due to these investors. As of December 31, 2014, no such amounts were due to these investors.
	The Company has accounted for these sale-leaseback arrangements in accordance with the Company’s accounting policy as described in Note 2, Summary of Significant Accounting Policies and Procedures.
Sale-Leaseback Financing Obligation [Member]
Sale Leaseback Transaction [Line Items]
Sale-Leaseback Arrangements	15. Sale-Leaseback Financing Obligation
	In November 2009, the Company entered into an arrangement with an investor to finance the development, construction and installation of a ground mounted solar system that was leased to a customer. The Company also entered into an agreement to sell the system to the investor for a cash consideration of $27.2 million, of which $23.7 million was received prior to December 31, 2014 and the balance of $3.5 million is receivable at the end of the lease period and accrues interest at an annual rate of 4.37%. Concurrent with the sale, a subsidiary of the Company entered into an agreement with the investor to lease back the solar energy system from the investor with lease payments being made on a quarterly basis. The Company’s subsidiary has the option to purchase the system at the end of the lease term of 10 years for a price which is the greater of the fair market value or a predetermined agreed upon value. Additionally, the investor has the option to put its interest in the solar system to the Company within two years following the expiry of six years after placement in service of the solar system, for a value that is the greater of the fair value or a predetermined agreed upon value. As a result of these put and call options, the Company has concluded that it has a continuing involvement with the solar energy system.
	The Company has determined that the ground mounted solar energy system qualifies as integral equipment and therefore as a real estate transaction under ASC 360-20, Real Estate Sales, and has been accounted for as a financing. Under the financing method, the receipts from the tax equity investor are reflected as a sale-leaseback financing obligation on the consolidated balance sheets, and the Company retains the solar energy system asset on the consolidated balance sheets within solar energy systems and depreciates the solar energy system over its estimated useful life of 30 years. The Company also continues to report all of the results of the operations of the system, with the revenue and expenses from the system operations being presented on the consolidated statements of operations on a “gross” basis. As of December 31, 2014, the balance of the sale-leaseback financing obligation outstanding was $14.3 million, of which $0.4 million has been classified as current and the balance of $13.9 million has been classified as noncurrent. As of December 31, 2013, the balance of the sale-leaseback financing obligation outstanding was $14.8 million, of which $0.4 million has been classified as current and the balance of $14.4 million has been classified as noncurrent.
	As of December 31, 2014, future minimum annual rentals to be received from the customer for each of the next five years and thereafter are as follows (in thousands):
	2015	$	475
	2016		485
	2017		494
	2018		504
	2019		514
	Thereafter		2,728
	Total	$	5,200
	The amounts in the table above are also included as part of the noncancelable operating lease payments from customers disclosed in Note 5, Noncancelable Operating Lease Payments Receivable.
	As of December 31, 2014, future minimum annual payments to be paid to the investor under the financing arrangement for each of the next five years and thereafter are as follows (in thousands):
	2015	$	1,257
	2016		1,264
	2017		1,270
	2018		1,277
	2019		1,284
	Thereafter		—
	Total	$	6,352
	The obligations of the Company’s subsidiary to the investor together with the obligations of the Company’s subsidiary under the sale-leaseback fund arrangement are guaranteed by the Company and supported by a $1.25 million restricted cash escrow that reduces by $0.25 million per annum for the first four years and remains in place until the end of the master lease period. As of December 31, 2014, $0.25 million was held as restricted cash.

Redeemable_Noncontrolling_Inte

Redeemable Noncontrolling Interests in Subsidiaries	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests in Subsidiaries	16. Redeemable Noncontrolling Interests in Subsidiaries
	Noncontrolling interests in subsidiaries that are redeemable at the option of the holder are classified as redeemable noncontrolling interests in subsidiaries between liabilities and stockholders’ equity in the consolidated balance sheets. The redeemable noncontrolling interests in subsidiaries balance is determined using the hypothetical liquidation at book value method for the VIE funds or allocation of share of income or losses in other subsidiaries subsequent to initial recognition, however, the noncontrolling interests balance cannot be less than the estimated redemption value. The activity of the redeemable noncontrolling interests in subsidiaries balance was as follows (in thousands):
	Balance at January 1, 2012	$	22,308
	Contributions from noncontrolling interests		46,293
	Net loss		8,696
	Distributions to noncontrolling interests		(54,714	)
	Acquisition of redeemable noncontrolling interest in subsidiaries		(9,756	)
	Balance at December 31, 2012		12,827
	Contributions from noncontrolling interests		172,913
	Net loss		(118,854	)
	Noncontrolling interest arising from acquisition of Paramount		549
	Energy
	Distributions to noncontrolling interests		(22,726	)
	Balance at December 31, 2013		44,709
	Contributions from redeemable noncontrolling interests		260,492
	Net loss		(141,072	)
	Distributions to redeemable noncontrolling interests		(14,313	)
	Transfers from noncontrolling interests in subsidiaries		25,248
	Redeemable noncontrolling interests arising from acquisition		14,174
	of Silevo
	Acquisition of redeemable noncontrolling interests in subsidiaries		(2,450	)
	Balance at December 31, 2014	$	186,788

Stockholders_Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Stockholders' Equity	17. Stockholders’ Equity
	Common Stock
	At the inception of the Company in June 2006, the founders were issued 4.0 million shares of common stock at an issuance price of $0.0001 per share.
	On December 18, 2012, the Company closed its initial public offering of its common stock and issued 11,434,988 shares of common stock at a price of $8.00 per share. On that same date, all then outstanding shares of the Company’s preferred stock converted into 50.4 million shares of its common stock. On December 20, 2012, the Company issued an additional 1,725,000 shares of common stock at a price of $8.00 per share pursuant to the underwriters’ exercise of their over-allotment option. The net proceeds realized from the initial public offering was $92.4 million net of underwriters discounts and commissions and offering costs of $12.9 million.
	On May 8, 2013, a fund investor exercised its warrants to purchase 1,485,010 shares of the Company’s common stock for $8.0 million.
	On September 6, 2013, the Company issued 3,674,565 shares of its common stock pursuant to its acquisition of the assets of Paramount Energy (see Note 3, Acquisitions).
	On October 21, 2013, the Company issued 3,910,000 shares of its common stock in a secondary public offering for aggregate proceeds of $174.1 million, net of underwriting discounts and offering expenses.
	On December 11, 2013, the Company issued 2,751,782 shares of its common stock pursuant to its acquisition of Zep Solar (see Note 3, Acquisitions).
	On September 23, 2014, the Company issued 2,284,070 shares of its common stock pursuant to its acquisition of Silevo (see Note 3, Acquisitions).
	Shares Reserved for Future Issuance
	The Company had reserved shares of common stock for future issuance as follows (in thousands):
		As of December 31,
		2014		2013
	Stock-based compensation plans:
	Awards available for grant		7,919		8,466
	Awards outstanding		14,979		13,969
	Employee Stock Purchase Plan		1,300		1,300
	Convertible senior notes outstanding		13,920		4,942
	Total		38,118		28,677

Equity_Award_Plans

Equity Award Plans	12 Months Ended
	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Award Plans	18. Equity Award Plans
	Stock Options
	Under the Company’s 2012 Equity Incentive Plan, the Company may grant incentive stock options and nonstatutory stock options for common stock to employees, directors and consultants. Stock options may be granted at an exercise price per share not less than 100% of the fair market value per share on the grant date. If an incentive stock option is granted to a 10% or greater stockholder, then the exercise price per share shall not be less than 110% of the fair market value per share on the grant date. Stock options granted are exercisable over a maximum term of 10 years from the date of grant and generally vest over a period of four years.
	In September 2012, the Company adopted a director compensation plan for future non-employee directors. Under the director compensation plan, each individual who joins the board of directors as a non-employee director following the adoption of the plan receives an initial stock option grant to purchase 30,000 shares of common stock at the time of initial election or appointment and additional triennial stock option grants to purchase 15,000 shares of common stock, as well as an annual cash retainer of $15,000, all of which are subject to continued service on the board of directors. Such non-employee directors who serve on committees of the board of directors receive various specified additional equity awards and cash retainers.
	Pursuant to the acquisition of Zep Solar, the Company assumed the Zep Solar, Inc. 2010 Equity Incentive Plan, or Zep Solar Plan, and issued fully vested stock options to purchase 303,151 shares of the Company’s common stock to replace certain fully vested stock options originally issued by Zep Solar. No additional equity awards were or will be granted under the Zep Solar Plan.
	A summary of stock option activity is as follows (in thousands, except per share amounts):
								Weighted-
					Weighted-			Average
					Average			Remaining			Aggregate
		Stock			Exercise			Contractual			Intrinsic
		Options			Price			Term			Value
	Outstanding - January 1, 2012		13,873		$	3.28			8.22		$	37,606
	Granted (weighted-average fair value of $11.08)		3,082			11.08
	Exercised		(902	)		1.91						9,000
	Canceled		(1,150	)		5.55
	Outstanding - December 31, 2012		14,903			4.8			7.67			107,653
	Granted (weighted-average fair value of $27.55)		4,364			39.02
	Issued in connection with a business acquisition		303			1.97
	(weighted-average fair value of $49.13)
	Exercised		(4,260	)		3.65						149,653
	Canceled		(1,361	)		15.3
	Outstanding - December 31, 2013		13,949			14.77			7.52			586,740
	Granted (weighted-average fair value of $47.45)		5,544			65.69
	Exercised		(3,176	)		6.38						185,822
	Canceled		(2,367	)		38.51
	Outstanding - December 31, 2014		13,950		$	32.89			7.64		$	342,293
	Options vested and exercisable - December 31, 2012		7,374		$	2.73			6.89		$	67,864
	Options vested and exercisable - December 31, 2013		6,696		$	4.62			6.54		$	349,523
	Options vested and exercisable - December 31, 2014		6,537		$	12.72			6.3		$	272,140
	Options vested and expected to vest - December 31, 2012		13,940		$	4.61			7.6		$	103,187
	Options vested and expected to vest - December 31, 2013		12,828		$	13.53			7.41		$	555,412
	Options vested and expected to vest - December 31, 2014		12,423		$	30.15			7.46		$	333,813
	As of December 31, 2014, approximately 27% of the outstanding stock options had a performance feature that is required to be satisfied before the option is vested and exercisable. The grant date fair market value of options that vested, excluding the fully vested options assumed in connection with the Zep Solar acquisition, in 2014, 2013 and 2012 was $54.9 million, $28.3 million and $13.3 million, respectively. The fair market value of the fully vested options assumed in connection with the Zep Solar acquisition was $14.9 million.
	As of December 31, 2014 and 2013, there was $242.9 million and $103.0 million, respectively, of total unrecognized stock-based compensation expense, net of estimated forfeitures, related to nonvested stock options, which are expected to be recognized over the weighted-average period of 2.76 years and 2.74 years, respectively.
	Under ASC 718, the Company estimates the fair value of stock options granted on each grant date using the Black-Scholes option valuation model and applies the straight-line method of expense attribution. The fair values were estimated on each grant date with the following weighted-average assumptions:
		Year Ended December 31,
		2014			2013			2012
	Dividend yield		0	%		0	%		0	%
	Annual risk-free rate of return		1.95	%		1.45	%		1.07	%
	Expected volatility		83.66	%		92.86	%		89.52	%
	Expected term (years)		6.25			6.06			6.19
	The expected volatility was calculated based on the average historical volatilities of publicly traded peer companies determined by the Company. The risk-free interest rate used was based on the U.S. Treasury yield curve in effect at the time of grant for the expected term of the stock options to be valued. The expected dividend yield was zero, as the Company does not anticipate paying a dividend within the relevant time frame. The expected term has been estimated using the simplified method allowed under ASC 718.
	Restricted Stock Units
	The Company began granting restricted stock units, or RSUs, to employees, directors and consultants in 2012 under the Company’s 2012 Equity Incentive Plan. A summary of RSU activity is as follows (in thousands, except per share amounts):
					Weighted-
		Restricted			Average
		Stock			Fair
		Units			Value
	Outstanding - January 1, 2012		—		$	—
	Granted		17			18.48
	Outstanding - December 31, 2012		17			18.48
	Granted		17			35
	Released		(14	)		50.18
	Outstanding - December 31, 2013		20			25.46
	Granted		1,097			61.92
	Released		(52	)		60.81
	Cancelled		(36	)		64.79
	Outstanding - December 31, 2014		1,029		$	61.16
	Expected to vest - December 31, 2014		776		$	61.45
	The grant date fair value of RSUs released was $3.2 million and $0.4 million for the year ended December 31, 2014 and 2013, respectively. Under ASC 718, the Company determines the fair value of RSUs granted on each grant date based on the fair value of the Company’s common stock on the grant date and applies the straight-line method of expense attribution. As of December 31, 2014 and 2013, there was $55.2 million and $0.5 million, respectively, of total unrecognized stock-based compensation expense, net of estimated forfeitures, from RSUs, which are expected to be recognized over the weighted-average period of 3.30 years and 1.99 years, respectively.
	Stock-Based Compensation Expense
	As part of the requirements of ASC 718, the Company is required to estimate potential forfeitures of equity awards and adjust stock-based compensation expense accordingly. The estimate of forfeitures will be adjusted over the requisite service period to the extent that actual forfeitures differ, or are expected to differ, from such estimates. Changes in estimated forfeitures will be recognized in the period of change and will also impact the amount of stock-based compensation expenses to be recognized in future periods.
	The amount of stock-based compensation expense recognized during the years ended December 31, 2014, 2013 and 2012 was $88.9 million, $27.9 million and $11.2 million, respectively.
	The amount of stock-based compensation expense that has been capitalized is as follows (in thousands):
	Year Ended December 31,
	2014			2013			2012
Capitalized under:
Inventories	$	192		$	433		$	318
Prepaid expenses and other current assets	$	4		$	—		$	—
Other assets	$	138		$	—		$	—
Property, plant and equipment - net	$	5,340		$	—		$	—
Solar energy systems, leased and to be leased - net	$	17,700		$	6,576		$	2,423
Stock-based compensation expense is included in cost of revenue and operating expenses as follows (in thousands):
	Year Ended December 31,
	2014			2013			2012
Cost of revenue	$	2,251		$	741		$	470
Sales and marketing	$	16,391		$	4,003		$	1,316
General and administrative	$	40,897		$	15,914		$	6,652
Research and development	$	6,023		$	269		$	—

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	19. Income Taxes
	The Company accounts for income taxes using the asset and liability method. Under this method, deferred income tax assets and liabilities are determined based upon the difference between the consolidated financial statement carrying amounts and the tax basis of assets and liabilities and are measured using the then enacted tax rate that is expected to be applicable to taxable income in the years in which the differences are expected to reverse.
	The following table presents domestic and foreign components of (loss) income  before income taxes for the periods presented (in thousands):
		Year Ended December 31,
		2014			2013			2012
	United States	$	(718,416	)	$	(272,603	)	$	(128,119	)
	Noncontrolling interest and redeemable
	noncontrolling interests		319,196			95,968			14,391
	Foreign		(2,746	)		78			56
	Total	$	(401,966	)	$	(176,557	)	$	(113,672	)
	The income tax (benefit) provision is composed of the following (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Current:
	Federal	$	10		$	10		$	10
	State		473			80			16
	Foreign		100			26			15
	Total Current Provision		583			116			41
	Deferred:
	Federal		(26,528	)		(22,691	)		12
	State		(791	)		(2,224	)		1
	Foreign		—			—			—
	Total Deferred Provision		(27,319	)		(24,915	)		13
	Total (benefit) provision for income taxes	$	(26,736	)	$	(24,799	)	$	54
	The following table presents a reconciliation of the statutory federal rate and the Company’s effective tax rate for the periods presented:
		Year Ended December 31,
		2014			2013			2012
	Tax benefit at federal statutory rate		(34.00	)%		(34.00	)%		(34.00	)%
	State income taxes (net of federal benefit)		(1.71	)		(0.88	)		(1.43	)
	Foreign income and withholding taxes		0.44			1.41			0
	Noncontrolling interests and redeemable noncontrolling		5.18			(16.62	)		(32.03	)
	interests adjustment
	Investment in certain financing funds		16.49			36.2			35.84
	Stock-based compensation		2.35			1.77			2.07
	ASC 810 prepaid tax expense		(5.45	)		(1.39	)		0
	Purchase accounting adjustment		0			0			21.24
	Other		1.24			(3.74	)		1.05
	Tax Credits		(1.49	)		(1.75	)		0
	Change in valuation allowance		10.3			4.96			7.3
	Effective tax rate		(6.65	)%		(14.04	)%		0.04	%
	Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents significant components of the Company’s deferred tax assets and liabilities for the periods presented (in thousands):
		As of December 31,
		2014			2013
	Deferred tax assets:
	Accruals and reserves	$	29,142		$	12,693
	Net operating losses		86,322			119,790
	Accelerated gain on assets		25,710			27,712
	Investment in certain financing funds		288,556			69,273
	Tax rebate revenue		41,710			47,360
	Stock-based compensation		21,769			5,873
	Other deferred tax assets		5,507			1,924
	Tax credits		10,849			4,577
	Gross deferred tax assets		509,565			289,202
	Valuation allowance		(111,222	)		(59,902	)
	Net deferred tax assets		398,343			229,300
	Deferred tax liabilities:
	Depreciation and amortization		(239,170	)		(125,765	)
	Investment in certain financing funds		(86,518	)		(69,203	)
	Initial direct costs related to customer solar energy		(72,700	)		(33,725	)
	system lease acquisition costs and Other deferred
	tax liabilities
	Gross deferred tax liabilities		(398,388	)		(228,693	)
	Net deferred taxes	$	(45	)	$	607
	An analysis of current and noncurrent deferred tax assets and liabilities is as follows (in thousands):
	As of December 31,
	2014			2013
Current:
Deferred tax assets	$	17,381		$	12,940
Less: valuation allowance		(4,232	)		(3,095	)
Net current deferred tax assets	$	13,149		$	9,845
Noncurrent:
Deferred tax assets	$	488,043		$	274,588
Deferred tax liabilities		(394,247	)		(227,021	)
Total noncurrent gross deferred tax assets		93,796			47,567
Less: valuation allowance		(106,990	)		(56,805	)
Net noncurrent deferred tax liabilities	$	(13,194	)	$	(9,238	)
The above tables reflect changes to the 2013 balances to reflect comparability in presentation for material deferred items separately disclosed in 2014.
As of December 31, 2014 and 2013, the Company had federal NOL carryforwards of approximately $439.8 million and $419.8 million, respectively. The NOL carryforwards expire at various dates beginning in 2026 if not utilized. In addition, the Company had NOLs for California income tax purposes of approximately $228.4 million and $186.1 million, as of December 31, 2014 and 2013, respectively, which expire at various dates beginning in 2020 if not utilized. The Company also had NOLs for other state income tax purposes of approximately $77.7 million and $77.2 million, as of December 31, 2014 and 2013, respectively, which expire at various dates beginning in 2015 if not utilized. Included in the Federal, California and other state NOL carryovers above, $229.5 million and $109.2 million, respectively, relate to stock option windfall deductions which, when realized, will be credited to equity.
As of December 31, 2014 and 2013, the Company had federal business tax credit carryforwards of approximately $7.2 million and $1.6 million, respectively. The net business tax credit carryforward begins to expire in 2028 if not utilized. As of December 31, 2014 and 2013, the Company had California business tax credit carryforwards of approximately $1.6 million and $0.2 million, respectively. As of December 31, 2014 and 2013, the Company had foreign tax credit carryforwards of approximately $2.2 million and $2.5 million, respectively, which begins to expire in 2023 if not utilized.
In December 2013, the Company acquired Zep Solar, a designer and supplier of mounting solutions for photovoltaic panels. The purchase consideration for the acquisition of Zep Solar, which comprised cash and stock, was $157.8 million. The Company recorded a total of $86.0 million of intangible assets and $97.9 million of goodwill as a result of its acquisition of Zep Solar. For GAAP purposes, the intangible assets are being amortized over a weighted-average life of approximately seven years. The goodwill associated with this acquisition is not deductible for income tax purposes. The Company also recorded a net $24.8 million of long-term deferred tax liabilities that were primarily related to the acquired intangible assets and NOLs, which will provide the Company a future source of taxable income. The recording of the deferred tax liability triggered the subsequent release of a deferred tax valuation allowance, which was accounted for outside of the Zep Solar purchase accounting. Accordingly, the Company released $24.8 million of its deferred tax asset valuation allowance subsequent to the acquisition, which was recognized as a benefit of income taxes during 2013.
In September 2014, the Company acquired Silevo, a designer and manufacturer of high performance solar cells. The purchase consideration for the acquisition of Silevo, which comprised cash and stock including consideration payable upon Silevo attaining certain production and efficiency milestones, was $270.9 million. The Company recorded a total of $119.0 million of intangible assets and $167.0 million of goodwill as a result of the acquisition. For GAAP purposes, the intangible assets are being amortized over a weighted-average life of 10 years. The goodwill associated with this acquisition is not deductible for income tax purposes. The Company also recorded $27.3 million of long-term net deferred tax liabilities that were primarily related to the acquired intangible assets and NOLs, which provide the Company with a source of future taxable income. The recording of the deferred tax liabilities triggered the release of $27.3 million of deferred tax asset valuation allowances, which was accounted for outside of the purchase accounting for Silevo and was recognized as a benefit of income taxes in 2014.
The deferred tax liabilities supporting the realizability of these deferred tax assets in both of the above acquisitions will reverse in the same period, are in the same jurisdiction and are of the same character as the temporary differences that gave rise to these deferred tax assets.
The Company’s valuation allowance increased by approximately $51.3 million for the year ended December 31, 2014 and increased by approximately $1.9 million for the year ended December 31, 2013. The increase in the valuation allowance was primarily related to the Company’s investment in solar financing funds. The valuation allowance is determined in accordance with the provisions of ASC 740, Income Taxes, which requires an assessment of both negative and positive evidence when measuring the need for a valuation allowance. Based on the available objective evidence and the Company’s history of losses, management believes it is more likely than not that the net deferred tax assets will not be realized. As of December 31, 2014 and 2013, the Company has applied a valuation allowance against its deferred tax assets net of the expected income from the reversal of the deferred tax liabilities.
Utilization of the NOL carryforwards and credits may be subject to a substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code of 1986, as amended, and similar state provisions. The annual limitation may result in the expiration of NOL and credits before utilization. Utilization of the NOL carryforwards and credits may be subject to a substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code of 1986, as amended, and similar state provisions. The annual limitation may result in the expiration of NOL and credits before utilization. The Company completed a Section 382 analysis through December 2014. Based on the analysis, NOL carryforwards presented have accounted for any limited and potential lost attributes due to any ownership changes and expiration dates. The Company also analyzed the NOL carryovers related to its acquisition of Zep Solar and Silevo. Based on the analysis, there were no significant limitations to the utilization of either Zep Solar’s or Silevo’s NOLs. The NOLs in the deferred table reflect the available NOLs not expected to expire unutilized.
As part of the assets monetization strategy, the Company has agreements to sell solar energy systems to the solar financing fund joint ventures. The gain on the sale of the assets has been eliminated in the consolidated financial statements. These transactions are treated as inter-company sales and as such, tax is not recognized on the sale until the Company no longer benefits from the underlying asset. Since the systems remain within the consolidated group, the tax expense incurred related to these sales is being deferred and amortized over the estimated useful life of the underlying systems which has been estimated to be 30 years. The deferral of the tax expense results in recording of a prepaid tax expense that is included in the consolidated balance sheets as other assets. As of December 31, 2014 and 2013, the Company recorded a long-term prepaid tax expense of $3.7 million and $3.7 million, respectively, net of amortization. The amortization of the prepaid tax expense in each period makes up the major component of the tax expense.
As a result of the Company’s acquisition of the noncontrolling interest in certain of its partnership funds during second quarter of 2014, the Company accounted for the direct impacts of the acquisition as an adjustment to other paid in capital, while the indirect impacts of the transaction were accounted for in the statement of operations. Since the Company owns 100% of these funds, the partnerships were treated as terminated for U.S. income tax purposes. Due to the deemed liquidation of these partnerships, no gain was recognized resulting from liquidating distributions of cash and assets. The Company also recognized a net deferred tax liability of $1.6 million resulting mainly from accelerated depreciation previously taken for tax purposes not for book purposes. The impact of setting up this deferred tax liability was offset by a release of valuation allowance, resulting in a net zero impact to the statement of operations.
The Company has an immaterial amount of undistributed earnings of foreign subsidiaries at December 31, 2014. Those earnings are considered to be indefinitely reinvested; accordingly, no provisions for U.S. federal and state income taxes have been provided thereon. Upon repatriation of those earnings, in the form of dividends or otherwise, the Company would be subject to both U.S. income taxes (subject to an adjustment for foreign tax credits) and withholding taxes payable to the various foreign countries. Determination of the amount of unrecognized deferred U.S. income tax liability is not practicable due to the complexities associated with its hypothetical calculation. In addition, unrecognized foreign tax credit carryforwards would be available to reduce a portion of such U.S. tax liability. An immaterial amount of withholding taxes may be payable upon remittance of all previously unremitted earnings at December 31, 2014.
On September 13, 2013, the U.S. Treasury Department and the Internal Revenue Service, or IRS, issued final regulations, Tangible Property Regulations, providing comprehensive guidance on the tax treatment of costs incurred to acquire, repair or improve tangible property. The final regulations are generally effective for taxable years beginning on or after January 1, 2014. On January 24, 2014, the IRS issued procedural guidance pursuant to which taxpayers will be granted automatic consent to change their tax accounting methods to comply with the final regulations. We are currently assessing the impact of these regulations but do not anticipate a material impact on our financial condition, results of operations or cash flows.
Uncertain Tax Positions
A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (in thousands):
Balance, January 1, 2013	$	—
Acquired from ZepSolar		120
Balance, December 31, 2013		120
Acquired from Silevo		434
True-up to prior year ending balance		(23	)
Balance, December 31, 2014	$	531
The interest expense and penalties for uncertain tax positions will be classified in the consolidated financial statements as income tax expense. There were no interest and penalties accrued for any uncertain tax positions as of December 31, 2014 and 2013.
The Company does not have any tax positions for which it is reasonably possible the total amount of gross unrecognized benefits will increase or decrease within 12 months of the year ended December 31, 2014.
The Company is subject to taxation and files income tax returns in the U.S., various state, local, and foreign jurisdictions. Due to the Company’s net losses, substantially all of its federal, state, local, and foreign income tax returns since inception are still subject to audit.

Defined_Contribution_Plan

Defined Contribution Plan	12 Months Ended
	Dec. 31, 2014
Compensation And Retirement Disclosure [Abstract]
Defined Contribution Plan	20. Defined Contribution Plan
	In January 2007, the Company established a 401(k) plan, or the Retirement Plan, available to employees who meet the Retirement Plan’s eligibility requirements. Participants may elect to contribute a percentage of their compensation to the Retirement Plan, up to a statutory limit. Participants are fully vested in their contributions. The Company may make discretionary contributions to the Retirement Plan as a percentage of participant contributions, subject to established limits. The Company did not make any contributions to the Retirement Plan during the years ended December 31, 2014, 2013 and 2012.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Related Party Transactions	21. Related Party Transactions
	The Company’s operations included the following related party transactions (in thousands):
		Year Ended December 31,
		2014		2013		2012
	Revenue:
	Solar energy systems sales to related parties	$	2,479	$	17	$	937
	Expenditures:
	Purchases of inventories from related parties	$	3,383	$	1,741	$	—
	Fees paid or payable to related parties (included in	$	103	$	81	$	—
	sales and marketing expense)
	Interest paid or payable to related parties (included in	$	3	$	—	$	—
	interest expense — net)
	Related party balances were comprised of the following (in thousands):
		As of December 31,
		2014		2013
	Due from related parties (included in accounts receivable)	$	30	$	9
	Due to related parties (included in accounts payable)	$	300	$	427
	Due to related parties (included in customer deposits)	$	—	$	83
	Due to related parties (included in long-term debt)	$	530	$	—
	Due to related parties (included in accrued and other current	$	3	$	—
	liabilities)
	Deferred revenue from related parties (included in current	$	—	$	831
	portion of deferred revenue)

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	22. Commitments and Contingencies
	Noncancelable Leases
	The Company leases offices, warehouse facilities, equipment, vehicles and solar energy systems under noncancelable leases. Aggregate rent expense for facilities and equipment for the years ended December 31, 2014, 2013 and 2012 was $32.9 million, $13.8 million and $4.2 million, respectively.
	Future minimum lease payments under noncancelable leases as of December 31, 2014 are as follows (in thousands):
	2015	$	26,432
	2016		23,172
	2017		19,451
	2018		13,835
	2019		11,472
	Thereafter		44,860
	Total minimum lease payments	$	139,222
	Build-to-Suit Lease Arrangement
	In September 2014, a subsidiary of the Company entered into a build-to-suit lease arrangement with the Research Foundation for the State University of New York, or the Foundation, for the construction of an approximately 1,000,000 square foot manufacturing facility with the capacity to produce at least 1 gigawatt of solar panels annually on an approximately 88.24 acre site located in Buffalo, New York. Under the terms of the agreement, the Foundation will construct the manufacturing facility and install certain utilities and other improvements, with participation by the Company as to the design and construction of the manufacturing facility, and acquire certain manufacturing equipment designated by the Company to be used in the manufacturing facility. The Foundation will cover construction costs related to the manufacturing facility in an amount up to $350.0 million and the acquisition and commissioning of the manufacturing equipment in an amount up to $400.0 million, in each case, subject to the maximum funding allocation from the State of New York, and the Company will be responsible for any construction and equipment costs in excess of such amounts. The Foundation will own the manufacturing facility and manufacturing equipment. Following completion of the manufacturing facility, the Company will lease the manufacturing facility from the Foundation for an initial period of 10 years, with an option to renew, for$1 per year plus utilities, and the Foundation will grant the Company the right to use the manufacturing equipment during the initial lease term at no charge.
	Under the terms of the build-to-suit lease arrangement, the Company is required to achieve specific operational milestones during the initial term of the lease, which include employing a certain number of employees at the facility and within the State of New York within specified time periods following the completion of the facility. The Company is also required to spend or incur approximately $5 billion in combined capital, operational expenses and other costs in the State of New York over the 10 years following full production. On an annual basis during the initial lease term, as measured on each anniversary of the commissioning of the facility, if the Company fails to meet its specified investment and job creation obligations, then it would be obligated to pay a $41.2 million “program payment” to the Foundation for each year that it fails to meet these requirements. Furthermore, if the agreement is terminated due to a material breach by the Company, then additional amounts might be payable by the Company.
	Due to the Company’s involvement with the construction of the facility, its exposure to any potential cost overruns and its other commitments under the agreement, the Company is deemed to be the owner of the facility and the manufacturing equipment for accounting purposes during the construction phase. Accordingly, as of December 31, 2014, the Company had recorded a build-to-suit lease asset under construction of $26.5 million, which is a component of property, plant and equipment – net, and a corresponding build-to-suit lease liability, which is a component of other liabilities and deferred credits, on the consolidated balance sheets.
	Indemnification and Guaranteed Returns
	As disclosed in Notes 12 and 14, the Company is contractually committed to compensate certain fund investors for any losses that they may suffer in certain limited circumstances resulting from reductions in U.S. Treasury grants or ITCs. Generally, such obligations would arise as a result of reductions to the value of the underlying solar energy systems as assessed by the U.S. Treasury Department for purposes of claiming U.S. Treasury grants or as assessed by the IRS for purposes of claiming ITCs or U.S. Treasury grants. For each balance sheet date, the Company assesses and recognizes, when applicable, the potential exposure from this obligation based on all the information available at that time, including any guidelines issued by the U.S. Treasury Department on solar energy system valuations for purposes of claiming U.S. Treasury grants and any audits undertaken by the IRS. The Company believes that any payments to the fund investors in excess of the amount already recognized by the Company for this obligation are not probable based on the facts known at the reporting date.
	The maximum potential future payments that the Company could have to make under this obligation would depend on the difference between the fair values of the solar energy systems sold or transferred to the funds as determined by the Company and the values that the U.S. Treasury Department would determine as fair value for the systems for purposes of claiming U.S. Treasury grants or the values the IRS would determine as the fair value for the systems for purposes of claiming ITCs or U.S. Treasury grants. The Company claims U.S. Treasury grants based on guidelines provided by the U.S. Treasury department and the statutory regulations from the IRS. The Company uses fair values determined with the assistance of independent third-party appraisals commissioned by the Company as the basis for determining the ITCs that are passed-through to and claimed by the fund investors. Since the Company cannot determine future revisions to U.S. Treasury Department guidelines governing system values or how the IRS will evaluate system values used in claiming ITCs or U.S. Treasury grants, the Company is unable to reliably estimate the maximum potential future payments that it could have to make under this obligation as of each balance sheet date.
	The Company is eligible to receive certain state and local incentives that are associated with renewable energy generation. The amount of incentives that can be claimed is based on the projected or actual solar energy system size and/or the amount of solar energy produced. The Company also currently participates in one state’s incentive program that is based on either the fair market value or the tax basis of solar energy systems placed in service. State and local incentives received are allocated between the Company and fund investors in accordance with the contractual provisions of each fund. The Company is not contractually obligated to indemnify any fund investor for any losses they may incur due to a shortfall in the amount of state or local incentives actually received.
	As disclosed in Note 12, VIE Fund Arrangements, the Company is contractually required to make payments to one fund investor to ensure that the fund investor achieves a specified minimum internal rate of return. The fund investor has already received a significant portion of the projected economic benefits from U.S. Treasury grant distributions and tax depreciation benefits. The contractual provisions of the fund state that the fund has an indefinite term unless the members agree to dissolve the fund. Based on the Company’s current financial projections regarding the amount and timing of future distributions to the fund investor, the Company does not expect to make any payments as a result of this guarantee and has not accrued any liabilities for this guarantee. The amount of potential future payments under this guarantee is dependent on the amount and timing of future distributions to the fund investor and future tax benefits that accrue to the fund investor. Due to the uncertainties surrounding estimating the amounts of these factors, the Company is unable to estimate the maximum potential payments under this guarantee. As of December 31, 2014, the fund investor has achieved the specified minimum internal rate of return as determined in accordance with the contractual provisions of the fund.
	As disclosed in Note 16, Lease Pass-Through Financing Obligation, the lease pass-through financing funds have a one-time lease payment reset mechanism that occurs after the installation of all solar energy systems in a fund. As a result of this mechanism, the Company may be required to refund master lease prepayments previously received from investors. Any refunds of master lease prepayments would reduce the lease pass-through financing obligation.
	Letters of Credit
	As of December 31, 2014, the Company had $15.1 million of unused letters of credit outstanding, which carry a fee of 3.375% per annum.
	Other Contingencies
	In July 2012, the Company, along with other companies in the solar energy industry, received a subpoena from the U.S. Treasury Department’s Office of the Inspector General to deliver certain documents in the Company’s possession that were dated, created, revised or referred to after January 1, 2007 and that relate to the Company’s applications for U.S. Treasury grants or communications with certain other solar energy development companies or with certain firms that appraise solar energy property for U.S Treasury grant application purposes. The Inspector General and the Civil Division of the U.S. Department of Justice are investigating the administration and implementation of the U.S Treasury grant program, including possible misrepresentations concerning the fair market value of the solar energy systems submitted by the Company in U.S. Treasury grant applications. If the Inspector General concludes that misrepresentations were made, the U.S. Department of Justice could decide to bring a civil action to recover amounts it believes were improperly paid to the Company. If the U.S. Department of Justice is successful in asserting this action, the Company could then be required to pay material damages and penalties for any funds received based on such misrepresentations, which, in turn, could require the Company to make indemnity payments to certain fund investors. The Company is unable to estimate the possible loss, if any, associated with this ongoing investigation as information is still being produced by the Company for further review by the Inspector General.
	On April 30, 2013, the U.S. Department of Labor, or DOL, notified the Company that it was undertaking a wage and hour investigation related to the Company’s Foster City, California facility. In the course of this investigation, the DOL subsequently asked the Company to provide information regarding certain employee positions throughout the Company for the three years preceding April 2013. On February 28, 2014, the DOL informed the Company that it had made a preliminary determination that some of its employee positions were not properly classified but has made no assessment of damages or penalties. If the DOL were to conclusively determine that the Company violated labor laws and regulations, the Company would be required to make the appropriate payments of back wages and other amounts to employees, and the Company might be subject to fines or penalties. The Company is currently unable to estimate the maximum potential exposure that may arise from this investigation based on the information currently available. The Company has recognized a liability as a result of this investigation.
	On March 28, 2014, a purported stockholder class action lawsuit was filed in the United States District Court for the Northern District of California against the Company and two of its officers. The complaint alleges claims for violations of the federal securities laws, and seeks unspecified compensatory damages and other relief on behalf of a purported class of purchasers of our securities from March 6, 2013 to March 18, 2014. The Company has filed a motion to dismiss the complaint.  The Company believes that the claims are without merit and intends to defend itself vigorously. The Company is unable to estimate the possible loss, if any, associated with this lawsuit.
	On June 5 and 11, 2014, stockholder derivative actions were filed in the Superior Court of California for the County of San Mateo, purportedly on behalf of the Company and against the board of directors, alleging that the board of directors breached its duties to the Company by failing to prevent the conduct alleged in the pending purported stockholder class action lawsuit. The Company and the individual board member defendants have filed a motion to dismiss the complaint. The Company is reviewing the claims asserted by the stockholders and is unable to estimate the possible loss, if any, associated with this lawsuit.
	From time to time, claims have been asserted, and may in the future be asserted, including claims from regulatory authorities related to labor practices and other matters. Such assertions arise in the normal course of the Company’s operations. The resolution of any such assertions or claims cannot be predicted with certainty.

Basic_and_Diluted_Net_Loss_Per

Basic and Diluted Net Loss Per Share	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Share	23. Basic and Diluted Net Loss Per Share
	The following table sets forth the computation of the Company’s basic and diluted net loss per share (in thousands, except share and per share amounts):
			Year Ended December 31,
			2014			2013			2012
	Net loss attributable to stockholders		$	(56,034	)	$	(55,790	)	$	(99,335	)
	Deemed dividend to Series G convertible redeemable			—			—			(10,091	)
	preferred stock prior to conversion(1)
	Net loss attributable to common stockholders, basic		$	(56,034	)	$	(55,790	)	$	(109,426	)
	Adjustment to revaluation of convertible redeemable			—			—			(277	)
	preferred stock warrants(2)
	Net loss attributable to common stockholders, diluted		$	(56,034	)	$	(55,790	)	$	(109,703	)
	Weighted-average shares used to compute net loss per share			93,333,880			79,781,976			14,240,187
	attributable to common stockholders, basic
	Weighted-average of dilutive convertible redeemable preferred stock warrants outstanding			—			—			27,580
	Weighted-average shares used to compute net loss per share			93,333,880			79,781,976			14,267,767
	attributable to common stockholders, diluted
	Net loss per share attributable to common stockholders, basic		$	(0.60	)	$	(0.70	)	$	(7.68	)
	Net loss per share attributable to common stockholders,		$	(0.60	)	$	(0.70	)	$	(7.69	)
	diluted
	-1	Deemed dividend to Series G convertible redeemable preferred stock prior to conversion represents the value attributable to a beneficial conversion feature associated with the Series G convertible redeemable preferred stock. The amount was calculated based upon the initial public offering of common stock price of $8.00 per share. Upon the closing of the initial public offering, each outstanding share of Series G convertible redeemable preferred stock converted automatically into a number of shares of common stock equal to the quotient obtained by dividing (A) the original issue price of $23.92 per share by (B) the greater of (i) 60% of the initial public offering price (before deducting underwriting discounts and commissions) and (ii) $9.68 (the conversion price of the Series F convertible redeemable preferred stock). As a result of this calculation, and based upon the initial public offering price of $8.00 per share, the 3,386,986 shares of Series G convertible redeemable preferred stock converted into 8,372,065 shares of common stock. The deemed dividend was calculated as the difference between the product of the number of shares of common stock issued upon conversion of the Series G convertible redeemable preferred stock multiplied by the estimated fair value of a share of common stock when the Series G convertible redeemable preferred stock was issued, less the proceeds that were realized upon the issuance of the Series G convertible redeemable preferred stock. The fair value of common stock used for this calculation was determined at each of the three closing dates of the issuance of Series G convertible redeemable preferred stock in February and March 2012. The fair value of common stock was estimated to be between $10.84 and $10.93 per share, based on an interpolation between the fair values the Company previously determined as of January 31, 2012 and March 12, 2012.
	-2	Adjustment to revaluation of convertible redeemable preferred stock warrants represents the impact of no revaluation of convertible redeemable preferred stock warrants, as discussed in Note 2, Summary of Significant Accounting Policies and Procedures, to reflect the potential impact of dilutive securities.
	The following outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive:
			Year Ended December 31,
			2014			2013			2012
	Convertible redeemable preferred stock			—			—			42,488,627
	Preferred stock warrants and common stock warrants			—			516,702			835,698
	Common stock options			14,332,220			14,412,968			14,623,766
	Restricted stock units			341,598			21,681			—
	Convertible senior notes			5,434,673			735,740			—

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	24. Subsequent Events
	New Debt Facility
	On January 9, 2015, certain subsidiaries of the Company obtained a non-recourse conduit financing facility. The conduit financing facility provides for up to $160.0 million of Class A notes and up to $40.0 million of Class B notes outstanding at any time during the term of the conduit financing facility. The Class A notes bear interest at a rate per annum equal to the cost of funds plus 2.5%, and the Class B notes bear interest at a rate per annum equal to the cost of funds plus 5.0%. Both notes are recourse to the payments owed to the Company or its subsidiaries under the MyPower program and are non-recourse to the Company’s other assets or cash flows. Both notes mature on January 20, 2017.
	New Financing Fund
	In February 2015, the Company formed two new non-recourse financing funds with new and existing fund investors with an aggregate financing commitment of $800.0 million.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies and Procedures (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation
	The accompanying consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles, or GAAP, and reflect the accounts and operations of the Company and those of its subsidiaries in which the Company has a controlling financial interest. In accordance with the provisions of Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, 810, Consolidation, the Company consolidates any variable interest entity, or VIE, of which it is the primary beneficiary. The typical condition for a controlling financial interest ownership is holding a majority of the voting interests of an entity; however, a controlling financial interest may also exist in entities, such as VIEs, through arrangements that do not involve controlling voting interests. ASC 810 requires a variable interest holder to consolidate a VIE if that party has the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. The Company does not consolidate a VIE in which it has a majority ownership interest when the Company is not considered the primary beneficiary. The Company has determined that it is the primary beneficiary of a number of VIEs (see Note 3, Acquisitions, and Note 12, VIE Fund Arrangements). The Company evaluates its relationships with all 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.
	The Company and its subsidiaries’ fiscal quarters and years are the same as calendar quarters and years except for one acquired subsidiary, Silevo, Inc., or Silevo, which continues to have fiscal quarters based on 13-week periods and fiscal years based on 52-week periods. For 2014, Silevo’s fiscal year ended on December 27, 2014, and it did not have any material activity between that date and December 31, 2014.
Reclassifications	Reclassifications
	Prior period research and development expenses were reclassified from general and administrative expense and disclosed separately as research and development expense in the consolidated financial statements and accompanying notes in order to provide comparability to current period balances. The reclassifications did not impact prior period results of operations, cash flows, total assets, total liabilities or total equity.
Use of Estimates	Use of Estimates
	The preparation of the consolidated financial statements requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. Management regularly makes significant estimates and assumptions regarding the selling price of undelivered elements for revenue recognition purposes, the collectability of accounts and rebates receivable, the valuation of inventories, the labor costs for long-term contracts used as a basis for determining the percentage of completion for such contracts, the fair values and residual values of solar energy systems subject to leases, the accounting for business combinations, the fair values and useful lives of acquired tangible and intangible assets, the fair value of debt assumed under business combinations, the fair value of contingent consideration payable under business combinations, the fair value of short-term investments, the useful lives of solar energy systems, property, plant and equipment, the determination of accrued warranty, the determination of accrued performance guarantee, the determination of lease pass-through financing obligations, the discount rates used to determine the fair values of investment tax credits, the valuation of stock-based compensation, the determination of valuation allowances associated with deferred tax assets, asset impairment and other items. Management bases its estimates on historical experience and on various other assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ materially from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents
	The Company considers all highly liquid investments with maturities of three months or less at the time of purchase to be cash equivalents. The Company maintains cash and cash equivalents, which consist principally of demand deposits with high-credit-quality financial institutions. The Company has exposure to credit risk to the extent cash and cash equivalent balances, including any restricted cash balances on deposit, exceed amounts covered by federal deposit insurance. The Company believes that its credit risk is not significant.
Short-Term Investments	Short-Term Investments
	The Company’s short-term investments comprise of corporate debt securities and asset-backed securities. The Company classifies short-term investments as available-for-sale and carries them at fair value, with any unrealized gains or losses recognized as other comprehensive income or loss in the consolidated balance sheet. The specific identification method is used to determine the cost of any securities disposed of, with any realized gains or losses recognized as other income or expense in the consolidated statement of operations. Short-term investments are anticipated to be used for current operations and are, therefore, classified as current assets even though their maturities may extend beyond one year. The Company periodically reviews short-term investments for impairment. In the event a decline in value is determined to be other-than-temporary, an impairment loss is recognized. When determining if a decline in value is other-than-temporary, the Company takes into consideration the current market conditions and the duration and severity of and the reason for the decline, as well as the likelihood that it would need to sell the security prior to a recovery of par value.
	The Company did not have any short-term investments as of December 31, 2013. As of December 31, 2014, short-term investments were comprised of $126.2 million of corporate debt securities and $12.1 million of asset-backed securities. The costs of these securities approximated their fair values, and there were no material gross realized or unrealized gains, gross realized or unrealized losses or impairment losses recognized for the year ended December 31, 2014. As of December 31, 2014, all short-term investments were scheduled to mature within the next twelve months.
Restricted Cash	Restricted Cash
	Restricted cash includes cash received from certain fund investors that had not been released for use by the Company, cash held to service certain payments under various securitization transactions including management expenses and principal and interest payments to solar asset-backed note holders and balances collateralizing outstanding letters of credit, outstanding credit card borrowing facilities and obligations under certain operating leases.
Accounts Receivable	Accounts Receivable
	Accounts receivable primarily represent trade receivables from sales to residential and commercial customers recorded at net realizable value. The Company maintains an allowance for doubtful accounts to reserve for potentially uncollectible accounts receivable. The Company reviews its accounts receivable by aging category to identify significant customer balances with known disputes or collection issues. In determining the allowance, the Company makes judgments about the creditworthiness of a majority of its customers based on ongoing credit evaluations. The Company also considers its historical level of credit losses and current economic trends that might impact the level of future credit losses. The Company writes off accounts receivable when they are deemed uncollectible.
Customer Notes Receivable	Customer Notes Receivable
	In the fourth quarter of 2014, the Company launched MyPower, a program that offers residential customers the option to finance the purchase of solar energy systems through a 30-year loan provided by a wholly owned subsidiary of the Company. In order to qualify for a loan, a customer must pass the Company’s credit evaluation process, and the loans are secured by the solar energy systems financed. The outstanding loan balances, net of any allowance for potentially uncollectible amounts, are presented on the consolidated balance sheets as a component of prepaid expenses and other current assets for the current portion and as customer notes receivable, net of current portion, for the long-term portion. In determining the allowance and credit quality, the Company identifies significant customers with known disputes or collection issues and considers its historical level of credit losses and current economic trends that might impact the level of future credit losses. Customer notes receivable that are individually impaired are charged-off as a write-off of allowance for losses. As of December 31, 2014, there were no significant customers with known disputes or collection issues, and the amount of potentially uncollectible amounts was also insignificant. Accordingly, the Company did not establish an allowance for losses against customer notes receivable. In addition, there were no non-accrual or past due customer notes receivable as of December 31, 2014.
Rebates Receivable	Rebates Receivable
	Rebates receivable represent rebates due from utility companies and government agencies. These receivables include rebates that have been assigned to the Company by its cash customers on state-approved solar energy system installations sold to the customers and also uncollected incentives from state and local government agencies for solar energy system installations that have been leased to customers or are used to generate and sell electricity to customers under power purchase agreements. For the rebates assigned to the Company by its customers, the Company assumes the responsibility for the application and collection of the rebate. The processing cycle for these rebates and incentives involves a multi-step process in which the Company accumulates and submits information required by the utility company or state agency necessary for the collection of the rebate. The entire process typically can take up to several months to complete. The Company recognizes rebates receivable upon the solar energy system passing inspection by the utility or authority having jurisdiction after completion of system installation. The Company maintains an allowance to reserve for potentially uncollectible rebates. In determining the allowance, the Company makes judgments based on the length of period that a rebate amount has been outstanding and reasons for the delays in collecting the rebate.
Concentrations of Risk	Concentrations of Risk
	Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents, short-term investments, accounts receivable and rebates receivable. The associated risk of concentration for cash and cash equivalents is mitigated by banking with creditworthy institutions. At certain times, amounts on deposit exceed federal deposit insurance limits. The associated risk of concentration for short-term investments is mitigated by holding a diversified portfolio of highly rated short-term investments. The Company does not require collateral or other security to support accounts receivable. To reduce credit risk, management performs periodic credit evaluations and ongoing evaluations of its customers’ financial condition. Rebates receivable are due from various states and local governments as well as various utility companies. The Company maintains reserves for any amounts that it considers to be uncollectable.
Fair Value of Financial Instruments	Fair Value of Financial Instruments
	ASC 820, Fair Value Measurements, clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or a liability.
	ASC 820 requires that the valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. ASC 820 establishes a three-tier fair value hierarchy, which prioritizes inputs that may be used to measure fair value as follows:
	—	Level 1—Observable inputs that reflect quoted prices for identical assets or liabilities in active markets.
	—	Level 2—Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	—	Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	As of December 31, 2013, there were no fair value measurements of assets or liabilities subsequent to initial recognition. As of December 31, 2014, the assets and liabilities carried at fair value on a recurring basis included cash equivalents, short-term investments and contingent consideration (see Note 3, Acquisitions). As of December 31, 2014, the fair value of the Company’s cash equivalents, short-term investments and contingent consideration were as follows (in thousands):
		Level 1				Level 2				Level 3
	Cash equivalents:
	Money market funds	$	54,229			$	—			$	—
	Corporate debt securities	$	—			$	7,599			$	—
	Short-term investments:
	Corporate debt securities	$	—			$	126,159			$	—
	Asset-backed securities	$	—			$	12,152			$	—
	Liabilities:
	Contingent consideration	$	—			$	—			$	117,197
	The Company classified its money market funds within Level 1 because their fair values are based on their quoted market prices. The Company classified its corporate debt securities and asset-backed securities within Level 2 because their fair values are determined using alternative pricing sources and models that utilized market observable inputs to determine their fair values. The Company classified its contingent consideration within Level 3 because their fair values are determined using unobservable probability estimates and an unobservable estimated discount rate applicable to the acquisition to determine the fair value. Furthermore, during the year ended December 31, 2014, there were no transfers between the levels of the fair value hierarchy.
	The contingent consideration is dependent on the achievement of specified production milestones for the acquired business as discussed in Note 3, Acquisitions. The fair value of the contingent consideration is directly proportional to the estimated probabilities of achievement of these milestones. As of December 31, 2014, the estimated probabilities ranged from 90% to 95%, the estimated discount rates ranged from 5.0% to 7.0%, $42.0 million was included under accrued and other current liabilities on the consolidated balance sheets and $75.2 million was included under other liabilities and deferred credits on the consolidated balance sheets. The following table summarizes the activity of the Level 3 contingent consideration balance in the year ended December 31, 2014 (in thousands):
	Balance - beginning of the period		$	—
	Acquisition of Silevo			115,319
	Change in fair value recorded in other income (expense) - net			1,878
	Balance - end of the period		$	117,197
	The Company’s financial instruments that are not re-measured at fair value include accounts receivable, customer notes receivable, rebates receivable, accounts payable, customer deposits, distributions payable to noncontrolling interests and redeemable noncontrolling interests, participation interest, solar asset-backed notes, convertible senior notes, Solar Bonds and long-term debt. The carrying values of these financial instruments other than the participation interest, solar asset-backed notes, convertible senior notes, Solar Bonds and long-term debt approximate their fair values due to the fact that they were short-term in nature at December 31, 2014 and 2013 (Level 1). The fair value of convertible senior notes was $752.2 million and $273.0 million as of December 31, 2014 and 2013, respectively, based on their last actively traded prices (Level 1). The Company estimates the fair value of customer notes receivable, solar asset-backed notes, Solar Bonds and long-term debt based on rates currently offered for debt with similar maturities and terms (Level 3). The Company has estimated the fair value of customer notes receivable, Solar Bonds and long-term debt to approximate their carrying values. The Company has estimated the fair value of solar asset-backed notes to be $328.3 million and $52.9 million as of December 31, 2014 and 2013, respectively. The Company has estimated the fair value of the participation interest to be $14.1 million and $15.1 million as of December 31, 2014 and 2013, respectively, based on rates currently offered for instruments with similar maturities and terms (Level 3).
Business Combinations	Business Combinations
	The Company accounts for business acquisitions under ASC 805, Business Combinations. The cost of an acquisition is measured at the fair value of the assets given, equity instruments issued and liabilities assumed at the acquisition date. Costs that are directly attributable to the acquisition are expensed as incurred. Identifiable assets, including intangible assets, acquired and liabilities, including contingent liabilities, assumed in the acquisition are measured initially at their fair values at the acquisition date. Any noncontrolling interests in the acquired business are also initially measured at fair value. The Company recognizes goodwill if the aggregate fair value of the total purchase consideration and the noncontrolling interests is in excess of the aggregate fair value of the identifiable assets acquired and the liabilities assumed.
Goodwill	Goodwill
	Goodwill represents the difference between the purchase price and the aggregate fair value of the identifiable assets acquired and the liabilities assumed in a business combination. The Company assesses goodwill impairment annually, in the fourth quarter of each fiscal year, and whenever events or changes in circumstances indicate that the carrying value of goodwill may exceed its fair value at the consolidated-level, which is the sole reporting unit. When assessing goodwill for impairment, the Company considers its market capitalization adjusted for a control premium and, if necessary, the Company’s discounted cash flow model, which involves significant assumptions and estimates, including the Company’s future financial performance, weighted-average cost of capital and interpretation of currently enacted tax laws. Circumstances that could indicate impairment and require the Company to perform an impairment test include a significant decline in the Company’s financial results, a significant decline in the Company’s market capitalization relative to its net book value, an unanticipated change in competition or the Company’s market share and a significant change in the Company’s strategic plans.
Inventories	Inventories
	Inventories include raw materials that include silicon wafers, process gasses, chemicals and other consumables used in solar cell production, solar cells, photovoltaic panels, inverters, mounting hardware and miscellaneous electrical components. Inventories also include work in process that includes raw materials partially installed and direct and indirect capitalized installation costs. Raw materials and work in process are stated at the lower of cost or market (on a first-in-first-out basis). Work in process primarily relates to solar energy systems that will be sold to customers, which are under construction and have yet to pass inspection.
	The Company also evaluates its inventory reserves on a quarterly basis and writes down the value of inventories for estimated excess and obsolete inventories based upon assumptions about future demand and market conditions.
Solar Energy Systems, Leased and To Be Leased	Solar Energy Systems, Leased and To Be Leased
	The Company is the operating lessor of the solar energy systems under leases that qualify as operating leases. The Company accounts for the leases in accordance with ASC 840, Leases. To determine lease classification, the Company evaluates lease terms to determine whether there is a transfer of ownership or bargain purchase option at the end of the lease, whether the lease term is greater than 75% of the useful life, or whether the present value of minimum lease payments exceed 90% of the fair value at lease inception. The Company utilizes periodic appraisals to estimate useful life and fair values at lease inception, and residual values at lease termination. Solar energy systems are stated at cost, less accumulated depreciation.
	Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the respective assets as follows.
			Useful Lives
	Solar energy systems leased to customers		30 years
	Initial direct costs related to customer solar energy		Lease term
	system lease acquisition costs		(10 to 20 years)
	Solar energy systems held for lease to customers are installed systems pending interconnection with the respective utility companies and will be depreciated as solar energy systems leased to customers when the respective systems have been interconnected and placed in service.
	Solar energy systems under construction represents systems that are under installation, which will be depreciated as solar energy systems leased to customers when the respective systems are completed, interconnected and subsequently leased to customers.
	Initial direct costs related to customer solar energy system lease acquisition costs are capitalized and amortized over the term of the related customer lease agreements.
Presentation of Cash Flows Associated with Solar Energy Systems	Presentation of Cash Flows Associated with Solar Energy Systems
	The Company classifies cash flows associated with solar energy systems in accordance with ASC 230, Statement of Cash Flows. The Company determines the appropriate classification of cash payments related to solar energy systems depending on the activity that is likely to be the predominant source of cash flows for the item being paid for. Accordingly, the Company presents payments made in a period for costs incurred to install solar energy systems that will be leased to customers, including the payments for cost of the inventory that is utilized in such systems, as investing activities in the consolidated statement of cash flows. Payments made for inventory that will be utilized for solar energy systems that will be sold to customers are presented as cash flows from operations in the consolidated statement of cash flows.
Property and Equipment	Property, Plant and Equipment
	Property, plant and equipment, including leasehold improvements, are stated at cost, less accumulated depreciation and amortization.
	Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the respective assets as follows.
			Useful Lives
	Furniture and fixtures		3-7 years
	Vehicles		5 years
	Computer hardware and software		3-10 years
	Manufacturing & lab equipment		2 to 3 years
	Buildings		20 years
	Land & land use rights		50 years
	Leasehold improvements are amortized over the shorter of the lease term or their estimated useful lives, currently seven years.
	Repairs and maintenance costs are expensed as incurred.
	Upon disposition, the cost and related accumulated depreciation of the assets are removed from property, plant and equipment and the resulting gain or loss is reflected in the consolidated statements of operations.
Property, Plant and Equipment, Impairment [Policy Text Block]	Long-Lived Assets
	The Company’s long-lived assets include property, plant and equipment, solar energy systems, leased and to be leased, and intangible assets acquired through business combinations. Intangible assets with definite useful lives are amortized over their estimated useful lives, which range from 1 to 30 years.
	In accordance with ASC 360, Property, Plant, and Equipment, the Company evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying value of a long-lived asset, or group of assets, as appropriate, may not be recoverable. If the aggregate undiscounted future net cash flows expected to result from the use and the eventual disposition of a long-lived asset is less than its carrying value, then the Company would recognize an impairment loss based on the discounted future net cash flows. No impairment charges were recorded for the years ended December 31, 2014, 2013 or 2012.
Capitalization of Software Costs	Capitalization of Software Costs
	For costs incurred in development of internal use software, the Company capitalizes costs incurred during the application development stage. Costs related to preliminary project activities and post implementation activities are expensed as incurred. Internal-use software is amortized on a straight-line basis over its estimated useful life of 10 years. The Company evaluates the useful lives of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets.
Warranties	Warranties
	The Company warrants its products for various periods against defects in material or installation workmanship. The Company generally provides a warranty on the generating and non-generating parts of the solar energy systems it sells of typically between 10 to 30 years. The manufacturer’s warranty on the solar energy systems’ components, which is typically passed-through to customers, ranges from one to 25 years. The changes in the accrued warranty balance, recorded as a component of accrued and other current liabilities on the consolidated balance sheets, consisted of the following (in thousands):
			As of and for the
			Year Ended
			December 31,
			2014				2013
	Balance - beginning of the period		$	7,502			$	4,019
	Change in estimate (credited) charged to warranty expense			(468	)			1,514
	Current year provision charged to warranty expense			2,022				2,257
	Assumed warranty obligation arising from business			—				188
	acquisitions
	Less warranty claims			(449	)			(476	)
	Balance - end of the period		$	8,607			$	7,502
Solar Energy Systems Performance Guarantees	Solar Energy Systems Performance Guarantees
	The Company guarantees certain specified minimum solar energy production output for certain systems leased or sold to customers generally for a term of 20 years. The Company monitors the solar energy systems to ensure that these outputs are being achieved. The Company evaluates if any amounts are due to its customers. As of December 31, 2014 and 2013, the Company had recorded liabilities of $1.6 million and $1.0 million, respectively, under accrued and other current liabilities in the consolidated balance sheets, relating to these guarantees based on the Company’s assessment of its current exposure.
Deferred U.S. Treasury Grants Income	Deferred U.S. Treasury Grants Income
	The Company is eligible for U.S. Treasury grants received or receivable on eligible property as defined under Section 1603 of the American Recovery and Reinvestment Act of 2009, as amended by the Tax Relief Unemployment Insurance Reauthorization and Job Creation Act of December 2010, which includes solar energy system installations, upon approval by the U.S. Treasury Department. However, to be eligible for U.S. Treasury grants, a solar energy system must have commenced construction in 2011 either physically or through the incurrence of sufficient project costs. For solar energy systems under lease pass-through fund arrangements, as described in Note 13, Lease Pass-Through Financing Obligation, the Company reduces the financing obligation and records deferred income for the U.S. Treasury grants which are paid directly to the investors upon receipt of the grants by the investors. The benefit of the U.S. Treasury grants is recorded as deferred income and is amortized on a straight-line basis over the estimated useful lives of the related solar energy systems of 30 years. The amortization of the deferred income is recorded as a reduction to depreciation expense, which is a component of the cost of revenue of operating leases and solar energy systems incentives in the consolidated statements of operations. A catch-up adjustment is recorded in the period in which the grant is approved by the U.S. Treasury Department or received by lease pass-through investors to recognize the portion of the grant that matches proportionally the amortization for the period between the date of placement in service of the solar energy systems and approval by the U.S. Treasury Department or receipt by lease pass-through investors of the associated grant. The changes in deferred U.S. Treasury grants income were as follows (in thousands):
	Balance at January 1, 2012		$	137,434
	U.S. Treasury grants received and receivable			112,520
	U.S. Treasury grants received by investors under lease			58,685
	pass-through fund arrangements
	Amortized as a credit to depreciation expense			(10,379	)
	Balance at December 31, 2012			298,260
	U.S. Treasury grants received and receivable			124,404
	U.S. Treasury grants received by investors under lease			20,599
	pass-through fund arrangements
	Amortized as a credit to depreciation expense			(15,454	)
	Balance at December 31, 2013			427,809
	U.S. Treasury grants received and receivable			342
	Amortized as a credit to depreciation expense			(15,335	)
	Balance at December 31, 2014		$	412,816
	Of the balance outstanding as of December 31, 2014 and 2013, $397.5 million and $412.5 million, respectively, are classified as noncurrent deferred U.S. Treasury grants income in the consolidated balance sheets.
Deferred Investment Tax Credits Revenue	Deferred Investment Tax Credits Revenue
	The Company’s solar energy systems are eligible for investment tax credits, or ITCs, that accrue to eligible property under the Internal Revenue Code. Under Section 50(d)(5) of the Internal Revenue Code and the related regulations, a lessor of qualifying property may elect to treat the lessee as the owner of such property for the purposes of claiming government ITCs associated with such property. These regulations enable the ITCs to be separated from the ownership of the property and allow the transfer of these ITCs. Under the lease pass-through fund arrangements, the Company can make a tax election to pass through the ITCs to the investor, who is the legal lessee of the property. The Company is therefore able to monetize the ITCs to investors who can utilize them in return for cash payments. The Company considers the monetization of ITCs to constitute one of the key elements of realizing the value associated with solar energy systems. The Company therefore views the proceeds from the monetization of ITCs to be a component of revenue generated from the solar energy systems.
	For the lease pass-through fund arrangements, the Company allocates a portion of the aggregate payments received from the investor to the estimated fair value of the assigned ITCs and the balance to the future customer lease payments that are also assigned to the investors. The estimated fair value of the ITCs are determined by discounting the estimated cash flows impact of the ITCs using an appropriate discount rate that reflects a market interest rate.
	The Company recognizes the revenue associated with the monetization of ITCs in accordance with ASC 605-10-S99, Revenue Recognition-Overall-SEC Materials. The revenue associated with the monetization of the ITCs is recognized when (1) persuasive evidence of an arrangement exists, (2) delivery has occurred or services have been rendered, (3) the sales price is fixed or determinable and (4) collection of the related receivable is reasonably assured. The ITCs are subject to recapture under the Internal Revenue Code if the underlying solar energy system either ceases to be a qualifying property or undergoes a change in ownership within five years of its placed in service date. The recapture amount decreases on the anniversary of the placed in service date. As the Company has an obligation to ensure the solar energy system is in service and operational for a term of five years to avoid any recapture of the ITCs, the Company recognizes revenue as the recapture provisions lapse assuming the other aforementioned revenue recognition criteria have been met. The monetized ITCs are initially recorded as deferred revenue on the consolidated balance sheet, and subsequently, one-fifth of the monetized ITCs is recognized as revenue from operating leases and solar energy systems incentives in the consolidated statement of operations on each anniversary of the solar energy system’s placed in service date over the next five years.
	The Company guarantees its fund investors that in the event of a subsequent recapture of the ITCs by the taxing authority due to the Company’s noncompliance with the applicable ITC guidelines, the Company will compensate the investor for any recaptured credits. The Company has concluded that the likelihood of a recapture event is remote and consequently has not recorded any liability in the consolidated financial statements for any potential recapture exposure.
	The balance of deferred investment tax credits revenue, which is included as part of deferred revenue in the consolidated balance sheets, as of December 31, 2014 and 2013 was $210.9 million and $139.5 million, respectively. For the year ended December 31, 2014 and 2013, the Company recognized $28.2 million and $0.5 million, respectively, of revenue related to the monetization of ITCs, which is included in operating leases and solar energy systems incentives revenue in the consolidated statements of operations. The Company had not recognized any revenue related to the monetization of ITCs prior to 2013.
Deferred Revenue	Deferred Revenue
	The Company records as deferred revenue any amounts that are collected from customers, including lease prepayments, in excess of revenue recognized. Deferred revenue also includes the portion of rebates and incentives received from utility companies and various local and state government agencies, which are recognized as revenue over the lease term, as well as the remote monitoring fee (discussed below), which is recognized as revenue ratably over the respective customer contract term. As of December 31, 2014 and 2013, deferred revenue related to customer payments, which is included in the deferred revenue balances in the consolidated balance sheets, amounted to $229.5 million and $186.9 million, respectively. As of December 31, 2014 and 2013, deferred revenue from rebates and incentives, which is included in the deferred revenue balances in the consolidated balance sheets, amounted to $169.6 million and $143.6 million, respectively. In addition, under MyPower customer contracts, all initial revenue associated with financed sales of solar energy systems are also recorded as a component of deferred revenue. As of December 31, 2014, deferred revenue from MyPower contracts amounted to $33.7 million.
Revenue Recognition	Revenue Recognition
	The Company provides design, installation, maintenance services and ongoing remote monitoring services for solar energy systems to residential and commercial customers. Customers generally purchase solar energy systems from the Company under fixed-price contracts or lease Company-owned solar energy systems, which also include remote monitoring services. A residential customer that purchases a solar energy system has the option to pay the full purchase price for the system at the time of purchase or finance the purchase through a 30-year loan from a wholly owned subsidiary of the Company, under the new MyPower program that the Company launched in the fourth quarter of 2014. The Company can also earn rebates, where available, that have been assigned to the Company by its customers on state-approved solar energy system installations sold to the customers, as well as rebates and incentives from utility companies and state and local governments on solar energy systems leased to customers or used to sell electricity to customers under power purchase agreements. The Company had also offered energy efficiency solutions aimed at improving residential energy efficiency and lowering overall residential energy costs. The energy efficiency services were comprised of energy efficiency evaluations and upgrades to homes and household appliances to improve energy efficiency.
	Solar Energy Systems and Components Sales
	For solar energy systems and components sales in which customers pay the full purchase price upon delivery of the system, the Company recognizes revenue, net of any applicable governmental sales taxes, in accordance with ASC 605-25, Revenue Recognition—Multiple-Element Arrangements, and ASC 605-10-S99, Revenue Recognition—Overall—SEC Materials. Revenue is recognized when (1) persuasive evidence of an arrangement exists, (2) delivery has occurred or services have been rendered, (3) the sales price is fixed or determinable and (4) collection of the related receivable is reasonably assured. Components comprise of photovoltaic panels and solar energy system mounting hardware. In instances where there are multiple deliverables in a single arrangement, the Company allocates the arrangement consideration to the various elements in the arrangement based on the relative selling price method. The Company recognizes revenue when it installs a solar energy system and the solar energy system passes inspection by the utility or the authority having jurisdiction, provided all other revenue recognition criteria have been met. Costs incurred on residential installations before the solar energy systems are completed are included in inventories as work in progress in the consolidated balance sheets.
	The Company recognizes revenue for solar energy systems constructed for certain commercial customers according to ASC 605-35, Revenue Recognition—Construction-Type and Production Type Contracts. Revenue is recognized on a percentage-of-completion basis, based on the ratio of labor costs incurred to date to total projected labor costs. Provisions are made for the full amount of any anticipated losses on a contract-by-contract basis. The Company recognized $2.1 million, $2.9 million and $2.6 million of total losses for these types of contracts for the years ended December 31, 2014, 2013 and 2012, respectively. Costs in excess of billings are recorded where costs recognized are in excess of amounts billed to customers of purchased commercial solar energy systems. Costs in excess of billings as of December 31, 2014 and 2013 were $0.3 million and $0.1 million, respectively, and are included in prepaid expenses and other current assets in the consolidated balance sheets. Billings in excess of costs as of December 31, 2014 and 2013 were $0.2 million and $0.2 million, respectively, and are included in deferred revenue in the consolidated balance sheets.
	For solar energy systems sold under a MyPower contract, the Company has determined that the arrangement consideration may not currently be fixed or determinable due to the lack of Company-specific or market history for similar programs with similar asset classes over an extended term. Accordingly, the Company initially defers the revenue associated with the sale of a solar energy system under a MyPower contract when it delivers a system that has passed inspection by the utility or the authority having jurisdiction. In instances where there are multiple deliverables in a single MyPower contract, the Company also allocates the arrangement consideration to the various elements in the contract based on the relative selling price method. Then, the Company recognizes revenue for the system over the term of the contract as the customer pays the loan’s principal and interest. The deferred revenue is included in the consolidated balance sheets under current portion of deferred revenue for the portion expected to be recognized as revenue in the next 12 months, and the non-current portion is included under deferred revenue, net of current portion. The Company records a note receivable when the customer secures a loan from a subsidiary of Company to finance the purchase.
	The costs associated with solar energy systems sold under MyPower contracts are initially capitalized as deferred costs of revenue and subsequently recognized as a component of cost of revenue from solar energy systems and components sales, generally in proportion to the reduction of the loan’s outstanding principal. The deferred cost of revenue is included in the consolidated balance sheets under prepaid expenses and other current assets for the portion expected to be recognized as cost of revenue in the next twelve months, and the non-current portion is included under other assets.
	The deferred revenue activity under MyPower was as follows (in thousands):
			As of and for the
			Year Ended
			December 31,
			2014
	Balance - beginning of the period		$	—
	MyPower agreements executed in the period			33,738
	Recognized in the period			(87	)
	Balance - end of the period		$	33,651
	Of the ending balance, $1.0 million is included in the consolidated balance sheets under current portion of deferred revenue, as of December 31, 2014. The balances in the table above do not include amounts allocated to remote monitoring services, other deliverables or sales taxes.
	The deferred cost of revenue activity under MyPower was as follows (in thousands):
			As of and for the
			Year Ended
			December 31,
			2014
	Balance - beginning of the period		$	—
	MyPower agreements executed in the period			13,614
	Recognized in the period			(43	)
	Balance - end of the period		$	13,571
	Of the ending balance, $0.4 million is included in the consolidated balance sheets under prepaid expenses and other current assets, as of December 31, 2014.
	Operating Leases and Power Purchase Agreements
	The Company is the lessor under lease agreements for solar energy systems, which are accounted for as operating leases in accordance with ASC 840. The Company records operating lease revenue from minimum lease payments, including upfront rebates and incentives earned from such systems, on a straight-line basis over the life of the lease term, assuming all other revenue recognition criteria are met. For incentives that are earned based on amount of electricity generated by the system, the Company records revenue as the amounts are earned.
	The difference between the payments received and the revenue recognized is recorded as deferred revenue in the consolidated balance sheets.
	For solar energy systems where customers purchase electricity from the Company under power purchase agreements, the Company has determined that these agreements should be accounted for, in substance, as operating leases pursuant to ASC 840. Revenue is recognized based upon the amount of electricity delivered at rates specified under the contracts, assuming all other revenue recognition criteria are met.
	The portion of rebates and incentives recognized within operating leases and solar energy systems incentives revenue for the years ended December 31, 2014, 2013 and 2012 was $33.4 million, $26.6 million and $18.2 million, respectively.
	Initial direct costs related to customer solar energy system lease acquisition costs (the incremental cost of contract administration, referral fees and sales commissions) are capitalized as an element of solar energy systems and amortized over the term of the related lease or power purchase agreement, which generally ranges from 10 to 20 years. Refer to Note 7, Solar Energy Systems, Leased and To Be Leased – Net, for a summary of initial direct costs related to customer solar energy system lease acquisition costs.
	Remote Monitoring Services
	The Company provides solar energy system remote monitoring services, which are generally bundled with both sales and leases of solar energy systems. The Company allocates revenue between remote monitoring services and the other elements in a bundled sale of a solar energy system using the relative selling price method. The selling prices used in the allocation are determined by reference to the prices charged by third parties for similar services and products on a standalone basis. For remote monitoring services bundled with a sale of a solar energy system, the Company recognizes the revenue allocated to remote monitoring services over the term specified in the associated contract or over the warranty period of the solar energy system if the contract does not specify the term. To date, remote monitoring services revenue has not been material and is included in the consolidated statements of operations under both operating leases and solar energy systems incentives revenue, when remote monitoring services are bundled with leases of solar energy systems, and solar energy system sales revenue, when remote monitoring services are bundled with sales of solar energy systems.
	Sale-Leaseback
	The Company is party to master lease agreements that provide for the sale of solar energy systems to third parties and the simultaneous leaseback of the systems, which the Company then subleases to customers. In sale-leaseback arrangements, the Company first determines whether the solar energy system under the sale-leaseback arrangement is “integral equipment.” A solar energy system is determined to be integral equipment when the cost to remove the system from its existing location, including the shipping and reinstallation costs of the solar energy system at the new site, including any diminution in fair value, exceeds ten percent of the fair value of the solar energy system at the time of its original installation. When the leaseback arrangements expire, the Company has the option to purchase the solar energy system, and in most cases, the lessor has the option to sell the system back to the Company, though in some instances the lessor can only sell the system back to the Company prior to expiration of the arrangement.
	For solar energy systems that the Company has determined to be integral equipment, the Company has concluded that these rights create a continuing involvement. Therefore, the Company uses the financing method to account for the sale-leaseback of such solar energy systems. Under the financing method, the Company does not recognize as revenue any of the sale proceeds received from the lessor that contractually constitutes a payment to acquire the solar energy system. Instead, the Company treats any such sale proceeds received as financing capital to install and deliver the solar energy system and accordingly records the proceeds as a sale-leaseback financing obligation in the consolidated balance sheets. The Company allocates the leaseback payments made to the lessor between interest expense and a reduction to the sale-leaseback financing obligation. Interest on the financing obligation is calculated using the Company’s incremental borrowing rate at the inception of the arrangement on the outstanding financing obligation. The Company determines its incremental borrowing rate by reference to the interest rates that it would obtain in the financial markets to borrow amounts equal to the sale-leaseback financing obligation over a term similar to the master lease term.
	For solar energy systems that the Company has determined not to be integral equipment, the Company determines if the leaseback is classified as a capital lease or an operating lease. For leasebacks classified as capital leases, the Company initially records a capital lease asset and capital lease obligation in the consolidated balance sheet equal to the lower of the present value of the future minimum leaseback payments or the fair value of the solar energy system. For capital leasebacks, the Company does not recognize any revenue but defers the gross profit comprising of the net of the revenue and the associated cost of sale. For leasebacks classified as operating leases, the Company recognizes a portion of the revenue and the associated cost of sale and defers the portion of revenue and cost of sale that represents the gross profit that is equal to the present value of the future minimum lease payments over the master leaseback term. For both capital and operating leasebacks, the Company records the deferred gross profit in the consolidated balance sheet as deferred income and amortizes the deferred income over the leaseback term as a reduction to the leaseback rental expense included in operating leases and solar energy systems incentives cost of revenue in the consolidated statement of operations.
Cost of Revenue	Cost of Revenue
	Operating leases and solar energy systems incentives cost of revenue is primarily comprised of depreciation of the cost of leased solar energy systems reduced by amortization of U.S. Treasury grants income, maintenance costs associated with those systems and amortization of initial direct lease costs associated with those systems.
	Solar energy systems and components sales cost of revenue includes direct and indirect material and labor costs, warehouse rent, freight, warranty expense, depreciation on vehicles and other overhead costs. In addition, for solar energy systems and components sales accounted for under the percentage-of-completion method, cost of revenue includes the full amount of any anticipated future losses on a contract-by-contract basis. However, for solar energy systems sold under MyPower contracts, the cost of revenue in a period is recognized in proportion to the revenue recognized for each system in the period.
Advertising Costs	Advertising Costs
	Advertising costs are expensed as incurred and are included as an element of sales and marketing expense in the consolidated statement of operations. The Company incurred advertising costs of $3.4 million, $0.5 million and $3.8 million for the years ended December 31, 2014, 2013 and 2012, respectively.
Income Taxes	Income Taxes
	The Company accounts for income taxes under an asset and liability approach. Deferred income taxes reflect the impact of temporary differences between assets and liabilities recognized for financial reporting purposes and the amounts recognized for income tax reporting purposes, net operating loss, or NOL, carryforwards and other tax credits measured by applying currently enacted tax laws. A valuation allowance is provided when necessary to reduce deferred tax assets to an amount that is more likely than not to be realized. The Company is eligible for federal investment tax credits. The Company accounts for federal investment tax credits under the flow-through method of accounting. As permitted in ASC 740-10-25-46, under the “flow-through” method of accounting, the tax benefit from an investment tax credit is recorded as a reduction of federal income taxes in the period that the credit is generated.
	The Company determines whether a tax position is more likely than not to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position. The Company uses a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates that it is more likely than not that the position will be sustained upon tax authority examination, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit as the largest amount that is more than 50% likely of being realized upon ultimate settlement.
	The Company’s policy is to include interest and penalties related to unrecognized tax benefits, if any, within the provision for taxes in the consolidated statements of operations.
Comprehensive Income (Loss)	Comprehensive Income (Loss)
	The Company accounts for comprehensive income (loss) in accordance with ASC 220, Comprehensive Income. Under ASC 220, the Company is required to report comprehensive income (loss), which includes net income (loss) as well as other comprehensive income (loss). There were no significant other comprehensive income (losses) and no significant differences between comprehensive loss as defined by ASC 220 and net loss as reported in the consolidated statements of operations, for the periods presented.
Solar Renewable Energy Credits	Solar Renewable Energy Credits
	The Company accounts for solar renewable energy credits, or SRECs, when they are minted by government agencies, purchased by the Company or sold to third parties. For SRECs generated by the Company’s solar energy systems and minted by government agencies, the Company does not recognize any specifically identifiable costs for those SRECs. For SRECs purchased by the Company, the Company carries these SRECs at their purchase price, subject to testing for impairment. When a SREC is sold to a third party, the Company recognizes operating leases and solar energy systems incentives revenue upon transfer of the SREC to the third party, and the cost of the SREC, if any, is recorded to operating leases and solar energy systems incentives cost of revenue.
Stock-Based Compensation	Stock-Based Compensation
	The Company accounts for stock-based compensation costs under the provisions of ASC 718, Compensation—Stock Compensation, which requires the measurement and recognition of compensation expense related to the fair value of stock-based compensation awards that are ultimately expected to vest. Stock-based compensation expense recognized includes the compensation cost for all share-based payments granted to employees based on the grant date fair value estimated in accordance with the provisions of ASC 718. ASC 718 is also applied to awards modified, repurchased, or canceled during the periods reported.
	The Company applies ASC 718 and ASC Subtopic 505-50, Equity-Based Payments to Non Employees, to options and other stock-based awards issued to nonemployees. In accordance with ASC 718 and ASC Subtopic 505-50, the Company uses the Black-Scholes option-pricing model to measure the fair value of the options at the measurement date. The measurement of stock-based compensation is subject to periodic adjustments as the awards vest and the resulting change in fair value is recognized in the consolidated statements of operations in the period the related services are rendered.
Noncontrolling Interests and Redeemable Noncontrolling Interests	Noncontrolling Interests and Redeemable Noncontrolling Interests
	Noncontrolling interests and redeemable noncontrolling interests represent third-party interests in the net assets under certain funding arrangements, or funds, that the Company has entered into to finance the cost of solar energy systems under operating leases. The Company has determined that the contractual provisions in the funds represent substantive profit sharing arrangements. The Company has further determined that the appropriate methodology for calculating the noncontrolling interest and redeemable noncontrolling interests balances that reflect the substantive profit sharing arrangements is a balance sheet approach using the hypothetical liquidation at book value, or HLBV, method. The Company therefore determines the amount of the noncontrolling interests and redeemable noncontrolling interests in the net assets at each balance sheet date using the HLBV method, which is presented on the consolidated balance sheets as noncontrolling interests in subsidiaries and redeemable noncontrolling interests in subsidiaries. Under the HLBV method, the amounts reported as noncontrolling interests and redeemable noncontrolling interests in the consolidated balance sheets represent the amounts the third parties would hypothetically receive at each balance sheet date under the liquidation provisions of the funds, assuming the net assets of the funds were liquidated at the recorded amounts determined in accordance with GAAP and distributed to the third parties. The third parties’ interests in the results of operations of the funds is determined as the difference in the noncontrolling interests and redeemable noncontrolling interests balance in the consolidated balance sheets between the start and end of each reporting period, after taking into account any capital transactions between the funds and the third parties. However, the redeemable noncontrolling interests balance is at least equal to the redemption amount. The noncontrolling interests and redeemable noncontrolling interests balance is presented as a component of permanent equity in the consolidated balance sheets or as temporary equity in the mezzanine section of the consolidated balance sheets as redeemable noncontrolling interests when the third-parties have the right to redeem their interests in the funds for cash or other assets.
Segment Information	Segment Information
	Operating segments are defined as components of a company about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or decision making group, in deciding how to allocate resources and in assessing performance. The Company’s chief operating decision maker is the executive team, which is comprised of the chief executive officer, the chief technology officer, the chief revenue officer, chief operating officer and the chief financial officer. Based on the financial information presented to and reviewed by the chief operating decision maker in deciding how to allocate the resources and in assessing the performance of the Company, the Company has determined that it has a single operating and reporting segment: solar energy products and services. The Company’s principal operations, revenue and decision-making functions are located in the United States.
Basic and Diluted Net Income (Loss) Per Share	Basic and Diluted Net Income (Loss) Per Share
	The Company’s basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period.
	Prior to the Company’s initial public offering of its common stock, its convertible redeemable preferred stock was entitled to receive dividends of up to $0.01 per share if dividends would have been declared on the common stock and thereafter would have participated pro rata on an as-converted basis with the common stockholders on any distributions to common stockholders. The convertible redeemable preferred stock was therefore a participating security. As a result, the Company calculated the net income (loss) per share using the two-class method. Accordingly, the net income (loss) attributable to common stockholders was derived from the net income (loss) for the period and, in periods in which the Company had net income attributable to common stockholders, an adjustment was made for the noncumulative dividends and allocations of earnings to participating securities based on their outstanding shareholder rights. Under the two-class method, the net loss attributable to common stockholders was not allocated to the convertible redeemable preferred stockholders as the convertible redeemable preferred stock did not have a contractual obligation to share in the Company’s losses.
	The diluted net income (loss) per share attributable to common stockholders is computed by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method or the if-converted method, as applicable. In periods when the Company incurred a net loss attributable to common stockholders, convertible redeemable preferred stock, stock options, restricted stock units, warrants to purchase common stock, warrants to purchase convertible redeemable preferred stock and convertible senior notes were considered to be common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is antidilutive.
Recently Issued Accounting Standards	Recently Issued Accounting Standards
	In May 2014, the FASB issued Accounting Standards Update, or ASU, No. 2014-09, Revenue from Contracts with Customers (Topic 606), to replace the existing revenue recognition criteria for contracts with customers and to establish the disclosure requirements for revenue from contracts with customers. The ASU is effective for interim and annual periods beginning after December 15, 2016. Adoption of the ASU is either retrospective to each prior period presented or retrospective with a cumulative adjustment to retained earnings or accumulated deficit as of the adoption date. The Company is currently assessing the impact of the ASU on its consolidated financial statements.
	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements — Going Concern (Subtopic 205-40), to provide guidance within GAAP requiring management to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and requiring related disclosures. The ASU is effective for annual periods ending after December 15, 2016. The Company believes that the ASU will have no impact on its consolidated financial statements.
	In February 2015, the FASB issued ASU No. 2015-02, Consolidation (Topic 810) — Amendments to the Consolidation Analysis, to amend the criteria for consolidation of certain legal entities. The ASU is effective for interim and annual periods beginning after December 15, 2015. Adoption of the ASU is either retrospective to each prior period presented or retrospective with a cumulative adjustment to retained earnings or accumulated deficit as of the adoption date. The Company is currently assessing the impact of the ASU on its consolidated financial statements.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies and Procedures (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Fair Value of Company's Cash Equivalents, Short-Term Investments and Contingent Consideration	As of December 31, 2014, the fair value of the Company’s cash equivalents, short-term investments and contingent consideration were as follows (in thousands):
		Level 1				Level 2				Level 3
	Cash equivalents:
	Money market funds	$	54,229			$	—			$	—
	Corporate debt securities	$	—			$	7,599			$	—
	Short-term investments:
	Corporate debt securities	$	—			$	126,159			$	—
	Asset-backed securities	$	—			$	12,152			$	—
	Liabilities:
	Contingent consideration	$	—			$	—			$	117,197
Summary of the Activity of the Level 3 Contingent Consideration	The following table summarizes the activity of the Level 3 contingent consideration balance in the year ended December 31, 2014 (in thousands):
	Balance - beginning of the period		$	—
	Acquisition of Silevo			115,319
	Change in fair value recorded in other income (expense) - net			1,878
	Balance - end of the period		$	117,197
Estimated Useful Lives of Respective Assets	Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the respective assets as follows.
			Useful Lives
	Solar energy systems leased to customers		30 years
	Initial direct costs related to customer solar energy		Lease term
	system lease acquisition costs		(10 to 20 years)
Estimated Useful Lives of Property, Plant and Equipment	Depreciation and amortization is calculated using the straight-line method over the estimated useful lives of the respective assets as follows.
			Useful Lives
	Furniture and fixtures		3-7 years
	Vehicles		5 years
	Computer hardware and software		3-10 years
	Manufacturing & lab equipment		2 to 3 years
	Buildings		20 years
	Land & land use rights		50 years
Schedule of Changes in Accrued Warranty Balance	The changes in the accrued warranty balance, recorded as a component of accrued and other current liabilities on the consolidated balance sheets, consisted of the following (in thousands):
			As of and for the
			Year Ended
			December 31,
			2014				2013
	Balance - beginning of the period		$	7,502			$	4,019
	Change in estimate (credited) charged to warranty expense			(468	)			1,514
	Current year provision charged to warranty expense			2,022				2,257
	Assumed warranty obligation arising from business			—				188
	acquisitions
	Less warranty claims			(449	)			(476	)
	Balance - end of the period		$	8,607			$	7,502
Schedule of Changes in Deferred U.S. Treasury Grant Income	The changes in deferred U.S. Treasury grants income were as follows (in thousands):
	Balance at January 1, 2012		$	137,434
	U.S. Treasury grants received and receivable			112,520
	U.S. Treasury grants received by investors under lease			58,685
	pass-through fund arrangements
	Amortized as a credit to depreciation expense			(10,379	)
	Balance at December 31, 2012			298,260
	U.S. Treasury grants received and receivable			124,404
	U.S. Treasury grants received by investors under lease			20,599
	pass-through fund arrangements
	Amortized as a credit to depreciation expense			(15,454	)
	Balance at December 31, 2013			427,809
	U.S. Treasury grants received and receivable			342
	Amortized as a credit to depreciation expense			(15,335	)
	Balance at December 31, 2014		$	412,816
Summary of Deferred Cost of Revenue Activity Under MyPower	The deferred revenue activity under MyPower was as follows (in thousands):
			As of and for the
			Year Ended
			December 31,
			2014
	Balance - beginning of the period		$	—
	MyPower agreements executed in the period			33,738
	Recognized in the period			(87	)
	Balance - end of the period		$	33,651
Deferred Cost By Arrangement Disclosure Text Block	The deferred cost of revenue activity under MyPower was as follows (in thousands):
			As of and for the
			Year Ended
			December 31,
			2014
	Balance - beginning of the period		$	—
	MyPower agreements executed in the period			13,614
	Recognized in the period			(43	)
	Balance - end of the period		$	13,571

Acquisition_Tables

Acquisition (Tables)	12 Months Ended
	Dec. 31, 2014
Silevo's Joint Venture in China [Member]
Summary of Fair Value of Assets Acquired, Liabilities Assumed and Noncontrolling Interest	The following table summarizes the carrying amounts of the JV’s assets and liabilities included in the Company’s consolidated balance sheet at December 31, 2014 (in thousands):
	Cash	$	1,401
	Inventories		614
	Prepaid and other current assets		1,224
	Property, plant and equipment - net		24,286
	Total assets	$	27,525
	Accounts payable	$	2,748
	Accrued and other current liabilities		633
	Current portion of long-term debt		9,134
	Total liabilities	$	12,515
Paramount Energy [Member]
Schedule of Determination of Fair Value Purchase Consideration as of Acquisition Date	The following table summarizes the fair value of the purchase consideration as of the acquisition date (in thousands):
	Cash	$	3,700
	Common stock		108,804
	Deferred consideration		4,039
	Total purchase consideration	$	116,543
Summary of Fair Value of Assets Acquired, Liabilities Assumed and Noncontrolling Interest	The following table summarizes the fair value of the assets acquired, liabilities assumed and the noncontrolling interest as of the acquisition date (in thousands):
	Cash	$	12
	Deposits and prepaid costs		409
	Solar energy systems under construction		2,130
	Solar energy systems, leased and to be leased		5,475
	Property and equipment		96
	Intangible assets		58,725
	Deferred revenue		(207	)
	Total identifiable net assets at fair value		66,640
	Noncontrolling interest		(549	)
	Goodwill		50,452
	Total purchase consideration	$	116,543
Summary of Intangible Assets Acquired	The following table summarizes the acquired intangible assets as of the acquisition date:
			Fair Value		Weighted-
					Average
					Useful Life
			(in thousands)		(in years)
	Marketing database	$	17,427		5
	PowerSaver agreement		17,077		10
	Solar energy systems backlog		12,434		30
	Non-compete agreement		6,959		5
	Mortgage database		4,628		3
	Funding commitment by fund investor		200		5
	Total	$	58,725
Zep Solar [Member]
Schedule of Determination of Fair Value Purchase Consideration as of Acquisition Date	The following table summarizes the determination of the fair value of the purchase consideration in the acquired business as of the acquisition date (in thousands):
	Cash	$	2,368
	Common stock		140,562
	Common stock options		14,893
	Total purchase consideration	$	157,823
Summary of Fair Value of Assets Acquired, Liabilities Assumed and Noncontrolling Interest	The following table summarizes the fair value of the assets acquired and liabilities assumed as of the acquisition date (in thousands):
	Cash	$	2,300
	Accounts receivable		1,293
	Inventory		4,255
	Property and equipment		366
	Other assets		251
	Accounts payable and other liabilities assumed		(9,646	)
	Deferred tax liabilities		(24,797	)
	Intangible assets		86,000
	Total identifiable net assets at fair value		60,022
	Goodwill		97,801
	Total purchase consideration	$	157,823
Summary of Intangible Assets Acquired	The following table summarizes the acquired intangible assets as of the acquisition date:
			Fair Value		Weighted-
					Average
					Useful Life
			(in thousands)		(in years)
	Developed technology	$	60,100		7
	Trademarks and trade names		24,700		7
	Customer orders backlog		700		1
	Internally developed software		500		3
	Total	$	86,000
Silevo, Inc [Member]
Schedule of Determination of Fair Value Purchase Consideration as of Acquisition Date	The table below summarizes the preliminary determination of the fair value of the purchase consideration as of the acquisition date (in thousands):
	Cash	$	326
	Common stock		137,958
	Restricted stock units issued to replace Silevo's unvested stock		132
	options
	Amounts advanced to Silevo prior to acquisition and costs paid		16,760
	on behalf of sellers at acquisition
	Closing consideration payable		413
	Contingent consideration payable		115,319
	Total purchase consideration	$	270,908
Summary of Fair Value of Assets Acquired, Liabilities Assumed and Noncontrolling Interest	The following table summarizes the preliminary assessment of the fair values of the assets acquired, the liabilities assumed and the noncontrolling interests as of the acquisition date (in thousands).
	Cash	$	2,899
	Accounts receivable		642
	Inventories		8,182
	Prepaid and other assets		899
	Property, plant and equipment		28,281
	Accounts payable and other liabilities		(5,427	)
	Term loan		(9,103	)
	Deferred tax liabilities		(27,332	)
	Intangible assets		119,000
	Total identifiable net assets at fair value		118,041
	Redeemable noncontrolling interests		(14,174	)
	Goodwill		167,041
	Total purchase consideration	$	270,908
Summary of Intangible Assets Acquired	The following table summarizes the acquired intangible assets as of the acquisition date:
					Weighted-
					Average
		Fair Value			Useful Life
		(in thousands)			(in years)
	Developed technology	$	115,000			10
	Build-to-suit lease arrangement		4,000			10
	Total	$	119,000
Unaudited Pro Forma Financial Information	The unaudited pro forma financial information for the acquisition of Silevo, as if it had been consummated on January 1, 2013, is as follows (in thousands):
		Year Ended December 31,
		2014			2013
	Total revenue	$	259,693		$	164,996
	Net loss attributable to common stockholders	$	(109,401	)	$	(95,764	)
	Net loss per share attributable to common	$	(1.15	)	$	(1.17	)
	stockholders, diluted

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	The following is a summary of intangible assets as of December 31, 2014 (in thousands):
											Transfers to
		Weighted-									solar energy
		average									systems,			Write-offs
		useful life						Accumulated			leased and to be			and
		(in years)			Gross			amortization			leased			cancellations			Net
	Developed technology - Silevo		10		$	115,000		$	(3,096	)	$	—		$	—		$	111,904
	Developed technology - Zep Solar		7			60,100			(9,070	)		—			—			51,030
	Trademarks and trade names		7			24,700			(3,728	)		—			—			20,972
	Marketing database		5			17,427			(4,599	)		—			—			12,828
	PowerSaver agreement		10			17,077			(2,253	)		—			—			14,824
	Solar energy systems backlog		30			12,434			—			(10,755	)		(1,679	)		—
	Non-compete agreement		5			6,959			(1,836	)		—			—			5,123
	Mortgage database		3			4,628			(2,035	)		—			—			2,593
	Build-to-suit lease arrangement		10			4,000			(108	)		—			—			3,892
	Customer orders backlog		1			700			(700	)		—			—			—
	Internally developed software		3			500			(176	)		—			—			324
	Funding commitment		5			200			(53	)		—			—			147
	Total		9.35		$	263,725		$	(27,654	)	$	(10,755	)	$	(1,679	)	$	223,637
	The following is a summary of intangible assets as of December 31, 2013 (in thousands):
											Transfers to
		Weighted-									solar energy
		average									systems,			Write-offs
		useful life						Accumulated			leased and to be			and
		(in years)			Gross			amortization			leased			cancellations			Net
	Developed technology - Zep Solar		7		$	60,100		$	(485	)	$	—		$	—		$	59,615
	Trademarks and trade names		7			24,700			(199	)		—			—			24,501
	Marketing database		5			17,427			(1,113	)		—			—			16,314
	PowerSaver agreement		10			17,077			(546	)		—			—			16,531
	Solar energy systems backlog		30			12,434			—			(10,615	)		(1,429	)		390
	Non-compete agreement		5			6,959			(444	)		—			—			6,515
	Mortgage database		3			4,628			(493	)		—			—			4,135
	Customer orders backlog		1			700			(89	)		—			—			611
	Internally developed software		3			500			(9	)		—			—			491
	Funding commitment		5			200			(13	)		—			—			187
	Total		8.82		$	144,725		$	(3,391	)	$	(10,615	)	$	(1,429	)	$	129,290
Summary of Carrying Value of Intangible Assets	The changes to the carrying value of intangible assets were as follows (in thousands):
		Year Ended December 31,
		2014			2013
	Balance - beginning of the period	$	129,290		$	—
	Acquisition of Paramount Energy		—			58,725
	Acquisition of Zep Solar		—			86,000
	Acquisition of Silevo		119,000			—
	Amortization		(24,263	)		(3,391	)
	Transfers to solar energy systems, leased and to be leased		(140	)		(10,615	)
	Write-offs and cancellations		(250	)		(1,429	)
	Balance - end of the period	$	223,637		$	129,290
Summary of Future Amortization Expense for Intangible Assets	As of December 31, 2014, total future amortization expense for intangible assets was as follows (in thousands):
	2015	$	32,349
	2016		31,846
	2017		30,639
	2018		29,068
	2019		25,722
	Thereafter		74,013
	Total	$	223,637
Summary of Carrying Value of Goodwill	The changes to the carrying value of goodwill were as follows (in thousands):
		Year Ended December 31,
		2014			2013
	Balance - beginning of the period	$	148,879		$	626
	Acquisition of Paramount Energy		—			50,452
	Acquisition of Zep Solar		—			97,801
	Acquisition of Silevo		167,041			—
	Balance - end of the period	$	315,920		$	148,879

Noncancelable_Operating_Lease_1

Noncancelable Operating Lease Payments Receivable (Tables)	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Summary of Future Minimum Lease Payments to be Received from Customers under Noncancelable Operating Leases	As of December 31, 2014, future minimum lease payments to be received from customers under noncancelable operating leases for each of the next five years and thereafter were as follows (in thousands):
	2015	$	54,759
	2016		54,076
	2017		54,827
	2018		55,681
	2019		56,547
	Thereafter		762,762
	Total	$	1,038,652

Inventories_Tables

Inventories (Tables)	12 Months Ended
	Dec. 31, 2014
Inventory Disclosure [Abstract]
Summary of Inventories	Inventories consisted of the following (in thousands):
		As of December 31,
		2014		2013
	Raw materials	$	209,251	$	105,919
	Work in progress		7,972		5,475
	Total	$	217,223	$	111,394

Solar_Energy_Systems_Leased_an1

Solar Energy Systems, Leased and To Be Leased - Net (Tables)	12 Months Ended
	Dec. 31, 2014
Property Subject To Or Available For Operating Lease [Line Items]
Schedule of Future Minimum Annual Lease Receipts from Sublessees	As of December 31, 2014, future minimum lease receipts to be paid to the Company by sub-lessees under this lease arrangement for each of the next five years and thereafter were as follows (in thousands):
	2015	$	2,428
	2016		2,451
	2017		2,480
	2018		2,511
	2019		2,542
	Thereafter		34,273
	Total	$	46,685
Solar Energy Systems Leased and to be Leased [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Components of Solar Energy Systems, Leased and to Be Leased	Solar energy systems, leased and to be leased – net consisted of the following (in thousands):
		As of December 31,
		2014			2013
	Solar energy systems leased to customers	$	2,388,548		$	1,513,731
	Initial direct costs related to customer solar energy		207,537			94,321
	system lease acquisition costs
			2,596,085			1,608,052
	Less accumulated depreciation and amortization		(159,160	)		(86,457	)
			2,436,925			1,521,595
	Solar energy systems under construction		131,048			53,010
	Solar energy systems to be leased to customers		228,823			107,916
	Solar energy systems, leased and to be leased - net	$	2,796,796		$	1,682,521
Schedule of Future Minimum Lease Payments to Lessor	As of December 31, 2014, future minimum lease payments to the lessor under this lease arrangement for each of the next five years and thereafter were as follows (in thousands):
	2015	$	2,327
	2016		2,339
	2017		2,353
	2018		2,367
	2019		2,383
	Thereafter		21,072
	Total	$	32,841

Property_Plant_and_Equipment_N1

Property Plant and Equipment - Net (Tables)	12 Months Ended
	Dec. 31, 2014
Property Plant And Equipment [Abstract]
Components of Property and Equipment	Property, plant and equipment consisted of the following (in thousands):
		As of December 31,
		2014			2013
	Vehicles	$	28,815		$	23,548
	Computer hardware and software		28,724			7,381
	Furniture and fixtures		5,501			2,653
	Leasehold improvements		13,992			7,397
	Build-to-suit lease asset under construction		26,450			—
	Manufacturing and lab equipment		21,677			—
	Buildings		4,288			—
	Land and land use rights		2,423			—
	Other		569			167
			132,439			41,146
	Less accumulated depreciation and amortization		(30,525	)		(18,739	)
	Property, plant and equipment - net	$	101,914		$	22,407

Accrued_and_Other_Current_Liab1

Accrued and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Payables And Accruals [Abstract]
Schedule of Accrued and Other Current Liabilities	Accrued and other current liabilities consisted of the following (in thousands):
		As of December 31,
		2014		2013
	Accrued compensation	$	50,414	$	21,634
	Current portion of contingent consideration		41,978		—
	Accrued expenses		27,485		19,943
	Accrued sales and use taxes		10,438		5,229
	Accrued warranty		8,607		7,502
	Accrued professional services fees		6,813		4,031
	Current portion of capital lease obligation		3,430		1,555
	Current portion of deferred gain on sale-leaseback		3,243		3,243
	transactions
	Amounts refundable to an investor		—		5,699
	Income taxes payable		—		1,577
	Current portion of participation interest		—		1,744
	Total	$	152,408	$	72,157

Other_Liabilities_and_Deferred

Other Liabilities and Deferred Credits (Tables)	12 Months Ended
	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Summary of Other Liabilities and Deferred Credits	Other liabilities and deferred credits consisted of the following (in thousands):
		As of December 31,
		2014		2013
	Deferred gain on sale-leaseback transactions, net of current	$	54,790	$	58,033
	portion
	Build-to-suit lease liability		26,450		—
	Deferred rent expense		4,838		3,333
	Capital lease obligation		27,791		27,126
	Liability for receipts from an investor		3,213		72,520
	Contingent consideration		75,219		—
	Participation interest		15,556		14,114
	Other noncurrent liabilities		36,617		18,313
	Total	$	244,474	$	193,439

Indebtedness_Tables

Indebtedness (Tables)	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Summary of Debt	The following is a summary of the Company’s debt as of December 31, 2014 (dollars in thousands):
				Carrying Value, Net
				of Fees
		Unpaid						Unused
		Principal						Borrowing
		Balance		Current		Long-Term		Capacity		Interest Rate	Maturity Dates
	Recourse debt:
	Revolving credit facility	$	130,000	$	—	$	126,939	$	54,935	3.40%	December 2016
	Vehicle loans		9,724		2,647		7,077		—	1.9%-7.5%	March 2015 -
											June 2019
	2.75% Convertible senior notes due in 2018		230,000		—		230,000		—	2.80%	November 2018
	1.625% Convertible senior notes due in 2019		566,000		—		566,000		—	1.60%	November 2019
	Solar Bonds		3,943		1,150		2,793		—	2.0%-4.0%	October 2015 -
											October 2018
	Total recourse debt		939,667		3,797		932,809		54,935
	Non-recourse debt:
	Term loan assumed from Silevo acquisition		9,134		9,134		—		—	7.80%	June 2015
	Term loan due in May 2016		34,195		—		33,497		90,805	3.20%	May 2016
	Term loan due in December 2016		122,655		—		120,108		127,345	3.4%-3.5%	December 2016
	Solar Asset-backed Notes, Series 2013-1		49,519		3,291		46,228		—	4.80%	November 2038
	Solar Asset-backed Notes, Series 2014-1		67,676		2,779		64,897		—	4.60%	Apr-44
	Solar Asset-backed Notes, Series 2014-2		201,494		7,504		193,268		—	4.0%-Class A	Jul-44
										5.4%-Class B
	Total non-recourse debt		484,673		22,708		457,998		218,150
	Total debt	$	1,424,340	$	26,505	$	1,390,807	$	273,085
	The following is a summary of the Company’s debt as of December 31, 2013 (dollars in thousands):
				Carrying Value, Net
				of Fees
		Unpaid						Unused
		Principal						Borrowing
		Balance		Current		Long-Term		Capacity		Interest Rate	Maturity Date
	Recourse debt:
	Revolving credit facility	$	142,531	$	—	$	138,535	$	54,776	3.4%-5.5%	December 2016
	Vehicle loans		6,517		1,789		4,728		—	0.0%-7.5%	March 2015 -
											December 2018
	2.75% Convertible senior notes due in 2018		230,000		—		230,000		—	2.80%	November 2018
	Total recourse debt		379,048		1,789		373,263		54,776
	Non-recourse debt:
	Working capital financing		9,990		1,197		8,793		—	5.5%-5.6%	December 2024
	Credit facility for SolarStrong		5,733		149		5,297		344,000	6.8%-7.3%	June 2032 -
											December 2032
	Term loan due in June 2015		87,891		4,192		81,259		12,109	3.4%-3.7%	June 2015
	Solar Asset-backed Notes, Series 2013-1		52,935		3,155		49,780		—	4.80%	November 2038
	Total non-recourse debt		156,549		8,693		145,129		356,109
	Other debt		95		95		—		—
	Total debt	$	535,692	$	10,577	$	518,392	$	410,885
Schedule of Principal Maturities of Debt	The future scheduled principal maturities of debt as of December 31, 2014 were as follows (in thousands):
		Recourse Debt
		Excluding
		Convertible		Non-Recourse		Convertible
		Senior Notes		Debt		Senior Notes		Total
	2015	$	3,787	$	22,733	$	—	$	26,520
	2016		133,137		169,855		—		302,992
	2017		3,442		13,609		—		17,051
	2018		2,876		13,892		230,000		246,768
	2019		425		14,474		566,000		580,899
	Thereafter		—		250,110		—		250,110
	Total	$	143,667	$	484,673	$	796,000	$	1,424,340

VIE_Fund_Arrangements_Tables

VIE Fund Arrangements (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Number Of Funds By Type Of Investor And The Carrying Value	The table below shows the number of funds by type of investor and the carrying value of solar energy systems in the funds:
				Carrying
				Value of
	Investor	Number		Solar Energy
	Classifcation	of Funds		Systems
	Financial institutions		16	$	1,174,120
	Corporations		5		148,931
	Utilities		2		252,836
	Various other investors		1		5,572
	Total		24	$	1,581,459
Carrying Values of Assets and Liabilities of Subsidiary in Consolidated Balance Sheets	The aggregate carrying values of the VIEs’ assets and liabilities, after elimination of intercompany transactions and balances, in the consolidated balance sheets were as follows (in thousands):
		As of December 31,
		2014		2013
	Assets
	Current assets:
	Cash and cash equivalents	$	26,419	$	35,141
	Restricted cash		106		115
	Accounts receivable - net		6,769		4,802
	Rebates receivable		25,397		17,351
	Prepaid expenses and other current assets		615		3,831
	Total current assets		59,306		61,240
	Restricted cash		300		—
	Solar energy systems, leased and to be leased - net		1,581,459		759,148
	Other assets		3,780		2,777
	Total assets	$	1,644,845	$	823,165
	Liabilities
	Current liabilities:
	Distributions payable to noncontrolling interests and	$	8,552	$	20,390
	redeemable noncontrolling interests
	Current portion of deferred U.S. Treasury grant income		6,502		6,668
	Accrued and other current liabilities		336		615
	Customer deposits		6,405		5,291
	Current portion of deferred revenue		16,746		13,754
	Current portion of bank borrowings		—		251
	Total current liabilities		38,541		46,969
	Deferred revenue, net of current portion		256,200		206,324
	Bank borrowings, net of current portion		—		5,482
	Deferred U.S. Treasury grant income, net of current portion		170,548		180,566
	Other liabilities and deferred credits		10,825		1,893
	Total liabilities	$	476,114	$	441,234

Lease_PassThrough_Financing_Ob1

Lease Pass-Through Financing Obligation (Tables) (Investors [Member])	12 Months Ended
	Dec. 31, 2014
Investors [Member]
Summary of Future Minimum Lease Payments to be Received from Investors	As of December 31, 2014, the future minimum lease payments to be received from the investors under the lease pass-through fund arrangements for each of the next five years and thereafter were as follows (in thousands):
	2015	$	24,216
	2016		23,857
	2017		23,989
	2018		24,070
	2019		24,023
	Thereafter		76,468
	Total	$	196,623

SaleLeaseback_Financing_Obliga1

Sale-Leaseback Financing Obligation (Tables)	12 Months Ended
	Dec. 31, 2014
Leases [Abstract]
Schedule of Future Minimum Annual Rentals to Be Received from Customers	As of December 31, 2014, future minimum annual rentals to be received from the customer for each of the next five years and thereafter are as follows (in thousands):
	2015	$	475
	2016		485
	2017		494
	2018		504
	2019		514
	Thereafter		2,728
	Total	$	5,200
Schedule of Future Minimum Annual Lease Payments to Investor under Financing Arrangement	As of December 31, 2014, future minimum annual payments to be paid to the investor under the financing arrangement for each of the next five years and thereafter are as follows (in thousands):
	2015	$	1,257
	2016		1,264
	2017		1,270
	2018		1,277
	2019		1,284
	Thereafter		—
	Total	$	6,352

Redeemable_Noncontrolling_Inte1

Redeemable Noncontrolling Interests in Subsidiaries (Tables)	12 Months Ended
	Dec. 31, 2014
Noncontrolling Interest [Abstract]
Activity of Redeemable Noncontrolling Interests in Subsidiaries	The activity of the redeemable noncontrolling interests in subsidiaries balance was as follows (in thousands):
	Balance at January 1, 2012	$	22,308
	Contributions from noncontrolling interests		46,293
	Net loss		8,696
	Distributions to noncontrolling interests		(54,714	)
	Acquisition of redeemable noncontrolling interest in subsidiaries		(9,756	)
	Balance at December 31, 2012		12,827
	Contributions from noncontrolling interests		172,913
	Net loss		(118,854	)
	Noncontrolling interest arising from acquisition of Paramount		549
	Energy
	Distributions to noncontrolling interests		(22,726	)
	Balance at December 31, 2013		44,709
	Contributions from redeemable noncontrolling interests		260,492
	Net loss		(141,072	)
	Distributions to redeemable noncontrolling interests		(14,313	)
	Transfers from noncontrolling interests in subsidiaries		25,248
	Redeemable noncontrolling interests arising from acquisition		14,174
	of Silevo
	Acquisition of redeemable noncontrolling interests in subsidiaries		(2,450	)
	Balance at December 31, 2014	$	186,788

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Schedule of Reserved Shares of Common Stock for Future Issuance	The Company had reserved shares of common stock for future issuance as follows (in thousands):
		As of December 31,
		2014		2013
	Stock-based compensation plans:
	Awards available for grant		7,919		8,466
	Awards outstanding		14,979		13,969
	Employee Stock Purchase Plan		1,300		1,300
	Convertible senior notes outstanding		13,920		4,942
	Total		38,118		28,677

Equity_Award_Plans_Tables

Equity Award Plans (Tables)	12 Months Ended
	Dec. 31, 2014
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	A summary of stock option activity is as follows (in thousands, except per share amounts):
								Weighted-
					Weighted-			Average
					Average			Remaining			Aggregate
		Stock			Exercise			Contractual			Intrinsic
		Options			Price			Term			Value
	Outstanding - January 1, 2012		13,873		$	3.28			8.22		$	37,606
	Granted (weighted-average fair value of $11.08)		3,082			11.08
	Exercised		(902	)		1.91						9,000
	Canceled		(1,150	)		5.55
	Outstanding - December 31, 2012		14,903			4.8			7.67			107,653
	Granted (weighted-average fair value of $27.55)		4,364			39.02
	Issued in connection with a business acquisition		303			1.97
	(weighted-average fair value of $49.13)
	Exercised		(4,260	)		3.65						149,653
	Canceled		(1,361	)		15.3
	Outstanding - December 31, 2013		13,949			14.77			7.52			586,740
	Granted (weighted-average fair value of $47.45)		5,544			65.69
	Exercised		(3,176	)		6.38						185,822
	Canceled		(2,367	)		38.51
	Outstanding - December 31, 2014		13,950		$	32.89			7.64		$	342,293
	Options vested and exercisable - December 31, 2012		7,374		$	2.73			6.89		$	67,864
	Options vested and exercisable - December 31, 2013		6,696		$	4.62			6.54		$	349,523
	Options vested and exercisable - December 31, 2014		6,537		$	12.72			6.3		$	272,140
	Options vested and expected to vest - December 31, 2012		13,940		$	4.61			7.6		$	103,187
	Options vested and expected to vest - December 31, 2013		12,828		$	13.53			7.41		$	555,412
	Options vested and expected to vest - December 31, 2014		12,423		$	30.15			7.46		$	333,813
Summary of Fair Value of Stock Options Granted Using Weighted-Average Assumptions	The fair values were estimated on each grant date with the following weighted-average assumptions:
		Year Ended December 31,
		2014			2013			2012
	Dividend yield		0	%		0	%		0	%
	Annual risk-free rate of return		1.95	%		1.45	%		1.07	%
	Expected volatility		83.66	%		92.86	%		89.52	%
	Expected term (years)		6.25			6.06			6.19
Summary of RSU Activity	A summary of RSU activity is as follows (in thousands, except per share amounts):
					Weighted-
		Restricted			Average
		Stock			Fair
		Units			Value
	Outstanding - January 1, 2012		—		$	—
	Granted		17			18.48
	Outstanding - December 31, 2012		17			18.48
	Granted		17			35
	Released		(14	)		50.18
	Outstanding - December 31, 2013		20			25.46
	Granted		1,097			61.92
	Released		(52	)		60.81
	Cancelled		(36	)		64.79
	Outstanding - December 31, 2014		1,029		$	61.16
	Expected to vest - December 31, 2014		776		$	61.45
Summary of Stock-Based Compensation Expense Capitalized	The amount of stock-based compensation expense that has been capitalized is as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Capitalized under:
	Inventories	$	192		$	433		$	318
	Prepaid expenses and other current assets	$	4		$	—		$	—
	Other assets	$	138		$	—		$	—
	Property, plant and equipment - net	$	5,340		$	—		$	—
	Solar energy systems, leased and to be leased - net	$	17,700		$	6,576		$	2,423
Summary of Stock-Based Compensation Expense Recognized	Stock-based compensation expense is included in cost of revenue and operating expenses as follows (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Cost of revenue	$	2,251		$	741		$	470
	Sales and marketing	$	16,391		$	4,003		$	1,316
	General and administrative	$	40,897		$	15,914		$	6,652
	Research and development	$	6,023		$	269		$	—

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Components of Domestic and Foreign (Loss) Income before Income Taxes	The following table presents domestic and foreign components of (loss) income  before income taxes for the periods presented (in thousands):
		Year Ended December 31,
		2014			2013			2012
	United States	$	(718,416	)	$	(272,603	)	$	(128,119	)
	Noncontrolling interest and redeemable
	noncontrolling interests		319,196			95,968			14,391
	Foreign		(2,746	)		78			56
	Total	$	(401,966	)	$	(176,557	)	$	(113,672	)
Schedule of Income Tax (Benefit) Provision	The income tax (benefit) provision is composed of the following (in thousands):
		Year Ended December 31,
		2014			2013			2012
	Current:
	Federal	$	10		$	10		$	10
	State		473			80			16
	Foreign		100			26			15
	Total Current Provision		583			116			41
	Deferred:
	Federal		(26,528	)		(22,691	)		12
	State		(791	)		(2,224	)		1
	Foreign		—			—			—
	Total Deferred Provision		(27,319	)		(24,915	)		13
	Total (benefit) provision for income taxes	$	(26,736	)	$	(24,799	)	$	54
Schedule of Reconciliation of Effective Tax Rate	The following table presents a reconciliation of the statutory federal rate and the Company’s effective tax rate for the periods presented:
		Year Ended December 31,
		2014			2013			2012
	Tax benefit at federal statutory rate		(34.00	)%		(34.00	)%		(34.00	)%
	State income taxes (net of federal benefit)		(1.71	)		(0.88	)		(1.43	)
	Foreign income and withholding taxes		0.44			1.41			0
	Noncontrolling interests and redeemable noncontrolling		5.18			(16.62	)		(32.03	)
	interests adjustment
	Investment in certain financing funds		16.49			36.2			35.84
	Stock-based compensation		2.35			1.77			2.07
	ASC 810 prepaid tax expense		(5.45	)		(1.39	)		0
	Purchase accounting adjustment		0			0			21.24
	Other		1.24			(3.74	)		1.05
	Tax Credits		(1.49	)		(1.75	)		0
	Change in valuation allowance		10.3			4.96			7.3
	Effective tax rate		(6.65	)%		(14.04	)%		0.04	%
Schedule of Deferred Tax Assets and Liabilities	Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The following table presents significant components of the Company’s deferred tax assets and liabilities for the periods presented (in thousands):
		As of December 31,
		2014			2013
	Deferred tax assets:
	Accruals and reserves	$	29,142		$	12,693
	Net operating losses		86,322			119,790
	Accelerated gain on assets		25,710			27,712
	Investment in certain financing funds		288,556			69,273
	Tax rebate revenue		41,710			47,360
	Stock-based compensation		21,769			5,873
	Other deferred tax assets		5,507			1,924
	Tax credits		10,849			4,577
	Gross deferred tax assets		509,565			289,202
	Valuation allowance		(111,222	)		(59,902	)
	Net deferred tax assets		398,343			229,300
	Deferred tax liabilities:
	Depreciation and amortization		(239,170	)		(125,765	)
	Investment in certain financing funds		(86,518	)		(69,203	)
	Initial direct costs related to customer solar energy		(72,700	)		(33,725	)
	system lease acquisition costs and Other deferred
	tax liabilities
	Gross deferred tax liabilities		(398,388	)		(228,693	)
	Net deferred taxes	$	(45	)	$	607
Schedule of Current and Noncurrent Deferred Tax Assets and Liabilities	An analysis of current and noncurrent deferred tax assets and liabilities is as follows (in thousands):
		As of December 31,
		2014			2013
	Current:
	Deferred tax assets	$	17,381		$	12,940
	Less: valuation allowance		(4,232	)		(3,095	)
	Net current deferred tax assets	$	13,149		$	9,845
	Noncurrent:
	Deferred tax assets	$	488,043		$	274,588
	Deferred tax liabilities		(394,247	)		(227,021	)
	Total noncurrent gross deferred tax assets		93,796			47,567
	Less: valuation allowance		(106,990	)		(56,805	)
	Net noncurrent deferred tax liabilities	$	(13,194	)	$	(9,238	)
Reconciliation of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (in thousands):
	Balance, January 1, 2013	$	—
	Acquired from ZepSolar		120
	Balance, December 31, 2013		120
	Acquired from Silevo		434
	True-up to prior year ending balance		(23	)
	Balance, December 31, 2014	$	531

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Components of Related Party Transactions	The Company’s operations included the following related party transactions (in thousands):
		Year Ended December 31,
		2014		2013		2012
	Revenue:
	Solar energy systems sales to related parties	$	2,479	$	17	$	937
	Expenditures:
	Purchases of inventories from related parties	$	3,383	$	1,741	$	—
	Fees paid or payable to related parties (included in	$	103	$	81	$	—
	sales and marketing expense)
	Interest paid or payable to related parties (included in	$	3	$	—	$	—
	interest expense — net)
Summary of Related Party Balances	Related party balances were comprised of the following (in thousands):
		As of December 31,
		2014		2013
	Due from related parties (included in accounts receivable)	$	30	$	9
	Due to related parties (included in accounts payable)	$	300	$	427
	Due to related parties (included in customer deposits)	$	—	$	83
	Due to related parties (included in long-term debt)	$	530	$	—
	Due to related parties (included in accrued and other current	$	3	$	—
	liabilities)
	Deferred revenue from related parties (included in current	$	—	$	831
	portion of deferred revenue)

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2014
Commitments And Contingencies Disclosure [Abstract]
Future Minimum Lease Payments under Noncancelable Leases	Future minimum lease payments under noncancelable leases as of December 31, 2014 are as follows (in thousands):
	2015	$	26,432
	2016		23,172
	2017		19,451
	2018		13,835
	2019		11,472
	Thereafter		44,860
	Total minimum lease payments	$	139,222

Basic_and_Diluted_Net_Loss_Per1

Basic and Diluted Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2014
Earnings Per Share [Abstract]
Computation of Company's Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the Company’s basic and diluted net loss per share (in thousands, except share and per share amounts):
			Year Ended December 31,
			2014			2013			2012
	Net loss attributable to stockholders		$	(56,034	)	$	(55,790	)	$	(99,335	)
	Deemed dividend to Series G convertible redeemable			—			—			(10,091	)
	preferred stock prior to conversion(1)
	Net loss attributable to common stockholders, basic		$	(56,034	)	$	(55,790	)	$	(109,426	)
	Adjustment to revaluation of convertible redeemable			—			—			(277	)
	preferred stock warrants(2)
	Net loss attributable to common stockholders, diluted		$	(56,034	)	$	(55,790	)	$	(109,703	)
	Weighted-average shares used to compute net loss per share			93,333,880			79,781,976			14,240,187
	attributable to common stockholders, basic
	Weighted-average of dilutive convertible redeemable preferred stock warrants outstanding			—			—			27,580
	Weighted-average shares used to compute net loss per share			93,333,880			79,781,976			14,267,767
	attributable to common stockholders, diluted
	Net loss per share attributable to common stockholders, basic		$	(0.60	)	$	(0.70	)	$	(7.68	)
	Net loss per share attributable to common stockholders,		$	(0.60	)	$	(0.70	)	$	(7.69	)
	diluted
	—	Deemed dividend to Series G convertible redeemable preferred stock prior to conversion represents the value attributable to a beneficial conversion feature associated with the Series G convertible redeemable preferred stock. The amount was calculated based upon the initial public offering of common stock price of $8.00 per share. Upon the closing of the initial public offering, each outstanding share of Series G convertible redeemable preferred stock converted automatically into a number of shares of common stock equal to the quotient obtained by dividing (A) the original issue price of $23.92 per share by (B) the greater of (i) 60% of the initial public offering price (before deducting underwriting discounts and commissions) and (ii) $9.68 (the conversion price of the Series F convertible redeemable preferred stock). As a result of this calculation, and based upon the initial public offering price of $8.00 per share, the 3,386,986 shares of Series G convertible redeemable preferred stock converted into 8,372,065 shares of common stock. The deemed dividend was calculated as the difference between the product of the number of shares of common stock issued upon conversion of the Series G convertible redeemable preferred stock multiplied by the estimated fair value of a share of common stock when the Series G convertible redeemable preferred stock was issued, less the proceeds that were realized upon the issuance of the Series G convertible redeemable preferred stock. The fair value of common stock used for this calculation was determined at each of the three closing dates of the issuance of Series G convertible redeemable preferred stock in February and March 2012. The fair value of common stock was estimated to be between $10.84 and $10.93 per share, based on an interpolation between the fair values the Company previously determined as of January 31, 2012 and March 12, 2012.
	—	Adjustment to revaluation of convertible redeemable preferred stock warrants represents the impact of no revaluation of convertible redeemable preferred stock warrants, as discussed in Note 2, Summary of Significant Accounting Policies and Procedures, to reflect the potential impact of dilutive securities.
Schedule of Weighted-Average Outstanding Shares of Common Stock Equivalents Excluded from Computation of Diluted Net Loss Per Share	The following outstanding shares of common stock equivalents were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive:
			Year Ended December 31,
			2014			2013			2012
	Convertible redeemable preferred stock			—			—			42,488,627
	Preferred stock warrants and common stock warrants			—			516,702			835,698
	Common stock options			14,332,220			14,412,968			14,623,766
	Restricted stock units			341,598			21,681			—
	Convertible senior notes			5,434,673			735,740			—

Organization_Additional_Inform

Organization - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Solarcity corporation, date of incorporation	21-Jul-06

Summary_of_Significant_Account3

Summary of Significant Accounting Policies and Procedures - Additional Information (Detail) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Highly liquid investments maturities period	three months or less
Short-term investments	$138,311,000	$0		138,311,000
Gross unrealized gains or losses	0
Gross realized gains or losses	0
Short-term investments, gross unrealized loss position, twelve months or longer, fair Value	0			0
Past due customer notes receivable	0			0
Non-accrual customer notes receivable	0			0
Fair value measurements of assets on recurring basis		0
Fair value measurements of liabilities on recurring basis		0
Fair Value Inputs, Discount Rate	5.00%
Accrued and other current liabilities	152,408,000	72,157,000		152,408,000
Estimated fair value	14,100,000	15,100,000		14,100,000
Operating lease description	The Company accounts for the leases in accordance with ASC 840, Leases. To determine lease classification, the Company evaluates lease terms to determine whether there is a transfer of ownership or bargain purchase option at the end of the lease, whether the lease term is greater than 75% of the useful life, or whether the present value of minimum lease payments exceed 90% of the fair value at lease inception.
Minimum percentage of useful life for lease term	75.00%			75.00%
Percentage of minimum lease payment of fair value	90.00%			90.00%
Estimated useful lives	9 years 4 months 6 days	8 years 9 months 26 days
Impairment charges	0	0	0
Company generally provides a warranty on the generating and non-generating parts of the solar energy systems	10 to 30 years
Initial direct costs related to solar energy systems leased to customers	20 years
Liability recorded relating to guarantees	1,600,000	1,000,000		1,600,000
Deferred U.S. Treasury grant income, net of current portion	397,500,000	412,500,000		397,500,000
Deferred investment tax credits revenue	210,900,000	139,500,000		210,900,000
Revenue recognized related to monetization of ITCs	28,200,000	500,000
Deferred revenue	33,651,000			33,651,000
Recognized losses on contracts	2,100,000	2,900,000	2,600,000
Costs in excess of billings	300,000	100,000		300,000
Billings in excess of costs	200,000	200,000		200,000
Current portion of deferred revenue	86,238,000	59,899,000		86,238,000
Prepaid expenses and other current assets	55,729,000	27,020,000		55,729,000
Rebates and incentives recognized within operating leases and incentive revenue	33,400,000	26,600,000	18,200,000
Advertising costs	3,400,000	500,000	3,800,000
Percentage of tax benefit realized upon ultimate settlement	50.00%
Convertible redeemable preferred stock [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Convertible redeemable preferred stock dividends per share	$0.01
Customer payments [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Deferred revenue	229,500,000	186,900,000		229,500,000
Rebates and incentives [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Deferred revenue	169,600,000	143,600,000		169,600,000
U.S. Treasury grants [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Estimated useful lives	30 years
Manufacturer [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Company generally provides a warranty on the generating and non-generating parts of the solar energy systems	one to 25 years
MyPower Program [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Deferred revenue	33,700,000			33,700,000
Current portion of deferred revenue	1,000,000			1,000,000
Prepaid expenses and other current assets	400,000			400,000
Leasehold Improvements [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Property and equipment, Useful Lives	7 years
Internal-use software [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Estimated useful lives	10 years
Convertible senior notes [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Estimated fair value	752,200,000	273,000,000		752,200,000
Asset-backed notes [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Estimated fair value	328,300,000	52,900,000		328,300,000
Level 3 [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Accrued and other current liabilities	42,000,000			42,000,000
Other liabilities and deferred credits	75,200,000			75,200,000
Minimum [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Fair Value Inputs, Probability of Default	90.00%
Estimated useful lives	1 year
Initial direct costs related to solar energy systems leased to customers	10 years
Maximum [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Fair Value Inputs, Probability of Default	95.00%
Estimated useful lives	30 years
Initial direct costs related to solar energy systems leased to customers	20 years
Solar Energy Systems
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Purchase of solar energy systems through loan				30 years
Short-term investments [Member]
Summary Of Significant Accounting Policies And Recent Accounting Pronouncements [Line Items]
Short-term investments, corporate debt securities	126,200,000			126,200,000
Short-term investments, asset-backed securities	$12,100,000			12,100,000

Summary_of_Significant_Account4

Summary of Significant Accounting Policies and Procedures - Fair Value of Company's Cash Equivalents, Short-Term Investments and Contingent Consideration (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Short-term investments [Member]
Cash equivalents:
Short-term investments, corporate debt securities	$126,200
Short-term investments:
Short-term investments, asset-backed securities	12,100
Level 1 [Member] | Money Market Funds [Member] | Fair Value, Measurements, Recurring
Cash equivalents:
Money market funds	54,229
Level 2 [Member] | Fair Value, Measurements, Recurring | Short-term investments [Member]
Short-term investments:
Corporate debt securities	126,159
Short-term investments, asset-backed securities	12,152
Level 2 [Member] | Cash Equivalents | Fair Value, Measurements, Recurring
Cash equivalents:
Short-term investments, corporate debt securities	7,599
Level 3 [Member] | Fair Value, Measurements, Recurring
Liabilities:
Contingent consideration	$117,197

Summary_of_Significant_Account5

Summary of Significant Accounting Policies and Procedures - Summary of the Activity of the Level 3 Contingent Consideration (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Accounting Policies [Abstract]
Balance - beginning of the period	$0
Acquisition of Silevo	115,319
Change in fair value recorded in other income (expense) - net	1,878
Balance - end of the period	$117,197

Summary_of_Significant_Account6

Summary of Significant Accounting Policies and Procedures - Estimated Useful Lives of Respective Assets (Detail)	12 Months Ended
	Dec. 31, 2014
Property Plant And Equipment [Line Items]
Initial direct costs related to customer solar energy system lease acquisition costs	20 years
Minimum [Member]
Property Plant And Equipment [Line Items]
Initial direct costs related to customer solar energy system lease acquisition costs	10 years
Maximum [Member]
Property Plant And Equipment [Line Items]
Initial direct costs related to customer solar energy system lease acquisition costs	20 years
Solar energy systems leased and to be leased [Member]
Property Plant And Equipment [Line Items]
Solar energy systems leased to customers	30 years

Summary_of_Significant_Account7

Summary of Significant Accounting Policies and Procedures - Estimated Useful Lives of Property, Plant and Equipment (Detail)	12 Months Ended
	Dec. 31, 2014
Vehicles [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Useful Lives	5 years
Buildings [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Useful Lives	20 years
Land & land use rights [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Useful Lives	50 years
Minimum [Member] | Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Useful Lives	3 years
Minimum [Member] | Computer hardware and software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Useful Lives	3 years
Minimum [Member] | Manufacturing equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Useful Lives	2 years
Maximum [Member] | Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Useful Lives	7 years
Maximum [Member] | Computer hardware and software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Useful Lives	10 years
Maximum [Member] | Manufacturing equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, Useful Lives	3 years

Summary_of_Significant_Account8

Summary of Significant Accounting Policies and Procedures - Schedule of Changes in Accrued Warranty Balance (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance - beginning of the period	$7,502	$4,019
Change in estimate (credited) charged to warranty expense	-468	1,514
Current year provision charged to warranty expense	2,022	2,257
Assumed warranty obligation arising from business acquisitions		188
Less warranty claims	-449	-476
Balance - end of the period	$8,607	$7,502

Summary_of_Significant_Account9

Summary of Significant Accounting Policies and Procedures - Schedule of Changes in Deferred U.S. Treasury Grant Income (Detail) (U.S. Treasury grants [Member], USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
U.S. Treasury grants [Member]
Deferred Grant [Line Items]
Balance at January 1, 2012	$427,809	$298,260	$137,434
U.S. Treasury grants received and receivable	342	124,404	112,520
U.S. Treasury grants received by investors under lease pass-through fund arrangements		20,599	58,685
Amortized as a credit to depreciation expense	-15,335	-15,454	-10,379
Balance at December 31, 2012	$412,816	$427,809	$298,260

Recovered_Sheet1

Summary of Significant Accounting Policies and Procedures - Summary of Deferred Revenue Activity Under MyPower (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Deferred Revenue [Abstract]
MyPower agreements executed in the period	$33,738
Recognized in the period	-87
Balance - end of the period	$33,651

Recovered_Sheet2

Summary of Significant Accounting Policies and Procedures - Summary of Deferred Cost of Revenue Activity Under MyPower (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Accounting Policies [Abstract]
MyPower agreements executed in the period	$13,614
Recognized in the period	-43
Balance - end of the period	$13,571

Acquisitions_Additional_Inform

Acquisitions - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended	1 Months Ended	0 Months Ended
	Sep. 23, 2014	Dec. 31, 2014	Sep. 06, 2013	Oct. 31, 2013	Dec. 11, 2013	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Common stock issued for acquisition	2,284,070
Future obligation		117,197,000				$117,197,000	$0
Silevo's Joint Venture in China [Member]
Business Acquisition [Line Items]
Percentage of ownership interest acquired		65.70%				65.70%
Term of agreement		1 year
Automatic renewal period		1 year
Right of acquisition period		5 years
Paramount Energy [Member]
Business Acquisition [Line Items]
Cash consideration paid			3,700,000
Common stock issued for acquisition			3,674,565
Common stock shares held in escrow, period			30-Sep-14
Aggregate fair value of common stock on acquisition date			108,800,000
Future obligation			4,039,000	3,200,000
Common stock			108,804,000
Paramount Energy [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Common stock issued for acquisition			3,674,565
Paramount Energy [Member] | Common Stock Held In Escrow [Member]
Business Acquisition [Line Items]
Common stock shares held in escrow			379,146
Zep Solar [Member]
Business Acquisition [Line Items]
Cash consideration paid					2,368,000
Common stock issued for acquisition					2,751,782
Number of shares to be purchased under fully vested options							303,151
Common stock					140,562,000
Zep Solar [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Common stock issued for acquisition					2,751,793
Silevo, Inc [Member]
Business Acquisition [Line Items]
Cash consideration paid	326,000
Common stock	137,958,000
Future obligation	115,300,000	115,319,000				115,319,000
Purchase consideration advance	15,800,000
Changes in contingent consideration		19,800,000
Changes in deferred tax liability		3,600,000
Changes in Goodwill		23,400,000
Decrease in net loss		-3,600,000
Revenue from acquisition						1,100,000
Net loss from acquisition						-9,700,000
General and administration cost incurred during acquisition						3,500,000
Silevo, Inc [Member] | Maximum [Member]
Business Acquisition [Line Items]
Future obligation	150,000,000
Silevo, Inc [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Common stock issued for acquisition	2,284,070
Silevo, Inc [Member] | Common Stock Held In Escrow [Member]
Business Acquisition [Line Items]
Common stock shares held in escrow	429,301

Acquisitions_Schedule_of_Deter

Acquisitions - Schedule of Determination of Fair Value Purchase Consideration as of Acquisition Date (Detail) (USD $)	12 Months Ended	0 Months Ended	1 Months Ended	0 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 06, 2013	Oct. 31, 2013	Dec. 11, 2013	Dec. 31, 2013
Business Acquisition [Line Items]
Acquisition of Silevo	$115,319
Paramount Energy [Member]
Business Acquisition [Line Items]
Cash		3,700
Common stock		108,804
Future obligation		4,039	3,200
Acquisition of Silevo		116,543
Zep Solar [Member]
Business Acquisition [Line Items]
Cash				2,368
Common stock				140,562
Acquisition of Silevo				157,823	157,800
Stock Options Issued During Period Value Acquisitions				$14,893	$14,893

Acquisitions_Summary_of_Fair_V

Acquisitions - Summary of Fair Value of Assets Acquired, Liabilities Assumed and Noncontrolling Interest (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Oct. 31, 2013	Dec. 31, 2012	Sep. 06, 2013	Sep. 23, 2014
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Goodwill	$315,920	$148,879	$148,879	$626
Paramount Energy [Member]
Business Acquisition [Line Items]
Cash					12
Deposits and prepaid costs					409
Solar energy systems under construction					96
Intangible assets					58,725
Deferred revenue					-207
Total identifiable net assets at fair value					66,640
Noncontrolling interest					-549
Goodwill					50,452
Total purchase consideration					116,543
Paramount Energy [Member] | Asset under Construction
Business Acquisition [Line Items]
Solar energy systems under construction					2,130
Paramount Energy [Member] | Solar energy systems leased and to be leased [Member]
Business Acquisition [Line Items]
Solar energy systems under construction					5,475
Zep Solar [Member]
Business Acquisition [Line Items]
Cash		2,300
Solar energy systems under construction		366
Intangible assets		86,000
Total identifiable net assets at fair value		60,022
Goodwill		97,801
Total purchase consideration		157,823
Accounts receivable		1,293
Inventory		4,255
Other assets		251
Accounts payable and other liabilities assumed		-9,646
Deferred tax liabilities		-24,797
Silevo, Inc [Member]
Business Acquisition [Line Items]
Cash						2,899
Deposits and prepaid costs						899
Solar energy systems under construction						28,281
Intangible assets						119,000
Total identifiable net assets at fair value						118,041
Noncontrolling interest						-14,174
Goodwill						167,041
Total purchase consideration						270,908
Accounts receivable						642
Inventory						8,182
Accounts payable and other liabilities assumed						-5,427
Term loan						-9,103
Deferred tax liabilities						($27,332)

Acquisitions_Summary_of_Intang

Acquisitions - Summary of Intangible Assets Acquired (Detail) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Sep. 06, 2013	Dec. 31, 2014	Dec. 11, 2013	Dec. 31, 2013	Sep. 23, 2014
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets		$263,725		$144,725
Computer Software, Intangible Asset
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets		17,427		17,427
Power Saver Agreement
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets		17,077		17,077
Customer Lists
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets		12,434		12,434
Noncompete Agreements
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets		6,959		6,959
Mortgage Database
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets		4,628		4,628
Funding Commitment By Fund Investor
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets		200		200
Trademarks and Trade Names
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets		24,700		24,700
Internally Developed Software
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets		500		500
Paramount Energy [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets	58,725
Paramount Energy [Member] | Computer Software, Intangible Asset
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life	5 years
Acquired intangible assets	17,427
Paramount Energy [Member] | Power Saver Agreement
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life	10 years
Acquired intangible assets	17,077
Paramount Energy [Member] | Customer Lists
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life	30 years
Acquired intangible assets	12,434
Paramount Energy [Member] | Noncompete Agreements
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life	5 years
Acquired intangible assets	6,959
Paramount Energy [Member] | Mortgage Database
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life	3 years
Acquired intangible assets	4,628
Paramount Energy [Member] | Funding Commitment By Fund Investor
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life	5 years
Acquired intangible assets	200
Zep Solar [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life		7 years
Acquired intangible assets				86,000
Zep Solar [Member] | Developed Technology Rights
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life			7 years
Acquired intangible assets		60,100		60,100
Zep Solar [Member] | Trademarks and Trade Names
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life			7 years
Acquired intangible assets				24,700
Zep Solar [Member] | Order or Production Backlog
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life			1 year
Acquired intangible assets				700
Zep Solar [Member] | Internally Developed Software
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life			3 years
Acquired intangible assets				500
Silevo, Inc [Member]
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets					119,000
Silevo, Inc [Member] | Developed Technology Rights
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life		10 years
Acquired intangible assets					115,000
Silevo, Inc [Member] | Build-to-suit lease arrangement
Acquired Finite Lived Intangible Assets [Line Items]
Acquired intangible assets, weighted average useful life		10 years
Acquired intangible assets					$4,000

Acquisitions_Schedule_of_Preli

Acquisitions - Schedule of Preliminary Determination of Fair Value Purchase Consideration as of Acquisition Date (Detail) (USD $)	12 Months Ended	0 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Sep. 23, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Contingent consideration payable	$117,197		$0
Total purchase consideration	115,319
Silevo, Inc [Member]
Business Acquisition [Line Items]
Cash		326
Common stock		137,958
Amounts advanced to Silevo prior to acquisition and costs paid on behalf of sellers at acquisition	16,760
Closing consideration payable		413
Contingent consideration payable	115,319	115,300
Total purchase consideration		270,908
Silevo, Inc [Member] | Unvested Restricted Stock Units [Member]
Business Acquisition [Line Items]
Common stock		$132

Acquisitions_Unaudited_Pro_For

Acquisitions - Unaudited Pro Forma Financial Information (Detail) (Silevo, Inc [Member], USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Silevo, Inc [Member]
Business Acquisition Pro Forma Information Nonrecurring Adjustment [Line Items]
Total revenue	$259,693	$164,996
Net loss attributable to common stockholders	($109,401)	($95,764)
Net loss per share attributable to common stockholders, diluted	($1.15)	($1.17)

Acquisitions_Summary_of_Carryi

Acquisitions - Summary of Carrying Amounts of Assets and Liabilities (Detail) (Silevo's Joint Venture in China [Member], USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Silevo's Joint Venture in China [Member]
Business Acquisition [Line Items]
Cash	$1,401
Inventory	614
Deposits and prepaid costs	1,224
Property, plant and equipment - net	24,286
Total assets	27,525
Accounts payable	2,748
Accrued and other current liabilities	633
Current portion of long-term debt	9,134
Total liabilities	$12,515

Goodwill_and_Intangible_Assets2

Goodwill and Intangible Assets - Summary of Intangible Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	9 years 4 months 6 days	8 years 9 months 26 days
Intangible assets acquired, Gross	$263,725	$144,725
Accumulated Amortization	-27,654	-3,391
Intangible asset, Transfer to solar energy systems - leased and to be leased	-10,755	-10,615
Write offs and cancellations	-1,679	-1,429
Intangible asset, Net	223,637	129,290
Zep Solar [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired, Gross		86,000
Developed Technology Rights | Silevo, Inc. [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	10 years
Intangible assets acquired, Gross	115,000
Accumulated Amortization	-3,096
Intangible asset, Net	111,904
Developed Technology Rights | Zep Solar [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	7 years	7 years
Intangible assets acquired, Gross	60,100	60,100
Accumulated Amortization	-9,070	-485
Intangible asset, Net	51,030	59,615
Trademarks and Trade Names
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	7 years	7 years
Intangible assets acquired, Gross	24,700	24,700
Accumulated Amortization	-3,728	-199
Intangible asset, Net	20,972	24,501
Trademarks and Trade Names | Zep Solar [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired, Gross		24,700
Computer Software, Intangible Asset
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	5 years	5 years
Intangible assets acquired, Gross	17,427	17,427
Accumulated Amortization	-4,599	-1,113
Intangible asset, Net	12,828	16,314
Power Saver Agreement
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	10 years	10 years
Intangible assets acquired, Gross	17,077	17,077
Accumulated Amortization	-2,253	-546
Intangible asset, Net	14,824	16,531
Customer Lists
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	30 years	30 years
Intangible assets acquired, Gross	12,434	12,434
Intangible asset, Transfer to solar energy systems - leased and to be leased	-10,755	-10,615
Write offs and cancellations	-1,679	-1,429
Intangible asset, Net		390
Noncompete Agreements
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	5 years	5 years
Intangible assets acquired, Gross	6,959	6,959
Accumulated Amortization	-1,836	-444
Intangible asset, Net	5,123	6,515
Mortgage Database
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	3 years	3 years
Intangible assets acquired, Gross	4,628	4,628
Accumulated Amortization	-2,035	-493
Intangible asset, Net	2,593	4,135
Build-to-suit lease arrangement [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	10 years
Intangible assets acquired, Gross	4,000
Accumulated Amortization	-108
Intangible asset, Net	3,892
Customer orders backlog [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	1 year	1 year
Intangible assets acquired, Gross	700	700
Accumulated Amortization	-700	-89
Intangible asset, Net		611
Internally Developed Software
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	3 years	3 years
Intangible assets acquired, Gross	500	500
Accumulated Amortization	-176	-9
Intangible asset, Net	324	491
Internally Developed Software | Zep Solar [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets acquired, Gross		500
Funding Commitment By Fund Investor
Finite Lived Intangible Assets [Line Items]
Intangible assets, Weighted-average useful life (in years)	5 years	5 years
Intangible assets acquired, Gross	200	200
Accumulated Amortization	-53	-13
Intangible asset, Net	$147	$187

Goodwill_and_Intangible_Assets3

Goodwill and Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Finite Lived Intangible Assets [Line Items]
Estimated useful lives	9 years 4 months 6 days	8 years 9 months 26 days
Amortization	$24,263,000	$3,391,000
Intangible assets impairment	0	0
Intangible assets, Write off and cancellations	250,000	1,429,000
Operating leases and solar energy systems incentives [Member]
Finite Lived Intangible Assets [Line Items]
Amortization	10,000,000	600,000
Solar energy systems and components sales [Member]
Finite Lived Intangible Assets [Line Items]
Amortization	2,600,000
Sales and marketing [Member]
Finite Lived Intangible Assets [Line Items]
Amortization	11,700,000	2,800,000
Power Saver Agreement
Finite Lived Intangible Assets [Line Items]
Maximum available additional loan capacity	25,000
Estimated useful lives	10 years	10 years
Customer Lists
Finite Lived Intangible Assets [Line Items]
Estimated useful lives	30 years	30 years
Intangible assets, Write off and cancellations	$300,000	$1,400,000

Goodwill_and_Intangible_Assets4

Goodwill and Intangible Assets - Summary of Carrying Value of Intangible Assets (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Finite Lived Intangible Assets [Line Items]
Balance - beginning of the period	$129,290
Amortization	-24,263	-3,391
Transfers to solar energy systems, leased and to be leased	-140	-10,615
Write-offs and cancellations	-250	-1,429
Balance - end of the period	223,637	129,290
Paramount Energy [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition		58,725
Zep Solar [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition		86,000
Silevo, Inc [Member]
Finite Lived Intangible Assets [Line Items]
Acquisition	$119,000

Goodwill_and_Intangible_Assets5

Goodwill and Intangible Assets - Summary of Future Amortization Expense for Intangible Assets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Finite Lived Intangible Assets Future Amortization Expense [Abstract]
2015	$32,349
2016	31,846
2017	30,639
2018	29,068
2019	25,722
Thereafter	74,013
Total	$223,637	$129,290

Goodwill_and_Intangible_Assets6

Goodwill and Intangible Assets - Summary of Carrying Value of Goodwill (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2014	Oct. 31, 2013	Dec. 31, 2012	Sep. 06, 2013	Sep. 23, 2014
Goodwill [Line Items]
Balance - beginning of the period			$148,879	$626
Balance - end of the period	148,879	315,920	148,879	626
Paramount Energy [Member]
Goodwill [Line Items]
Balance - beginning of the period					50,452
Acquisition of goodwill	50,452
Balance - end of the period					50,452
Zep Solar [Member]
Goodwill [Line Items]
Acquisition of goodwill	97,801
Balance - end of the period	97,801
Silevo, Inc [Member]
Goodwill [Line Items]
Balance - beginning of the period						167,041
Acquisition of goodwill		167,041
Balance - end of the period						$167,041

Noncancelable_Operating_Lease_2

Noncancelable Operating Lease Payments Receivable - Summary of Future Minimum Lease Payments to be Received from Customers under Noncancelable Operating Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Leases [Abstract]
2015	$54,759
2016	54,076
2017	54,827
2018	55,681
2019	56,547
Thereafter	762,762
Total	$1,038,652

Noncancelable_Operating_Lease_3

Noncancelable Operating Lease Payments Receivable - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Leases [Abstract]
Contingent rentals from customers	$79.50	$42	$20.20

Inventories_Summary_of_Invento

Inventories - Summary of Inventories (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Raw materials	$209,251	$105,919
Work in progress	7,972	5,475
Total	$217,223	$111,394

Inventories_Additional_Informa

Inventories - Additional Information (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Inventory Disclosure [Abstract]
Inventory reserves	$3.10	$1.40

Solar_Energy_Systems_Leased_an2

Solar Energy Systems, Leased and To Be Leased - Net - Components of Solar Energy Systems, Leased and to Be Leased (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Leases [Abstract]
Solar energy systems leased to customers	$2,388,548	$1,513,731
Initial direct costs related to customer solar energy system lease acquisition costs	207,537	94,321
Solar energy systems, leased and to be leased, gross	2,596,085	1,608,052
Less accumulated depreciation and amortization	-159,160	-86,457
Solar energy systems, leased and to be leased gross, less accumulated depreciation and amortization	2,436,925	1,521,595
Solar energy systems under construction	131,048	53,010
Solar energy systems to be leased to customers	228,823	107,916
Solar energy systems, leased and to be leased - net	$2,796,796	$1,682,521

Solar_Energy_Systems_Leased_an3

Solar Energy Systems, Leased and To Be Leased - Net - Additional Information (Detail) (Solar energy systems [Member], USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Solar energy systems [Member]
Capital Leased Assets [Line Items]
Capital leased assets	$66.40	$66.40
Accumulated depreciation on capital leased assets	$7.90	$5.30

Solar_Energy_Systems_Leased_an4

Solar Energy Systems, Leased and To Be Leased - Net - Schedule of Future Minimum Lease Payments to Lessor (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Leases [Abstract]
2015	$2,327
2016	2,339
2017	2,353
2018	2,367
2019	2,383
Thereafter	21,072
Total	$32,841

Solar_Energy_Systems_Leased_an5

Solar Energy Systems, Leased and To Be Leased - Net - Schedule of Future Minimum Annual Lease Receipts from Sublessees (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Operating Leased Assets [Line Items]
2015	$54,759
2016	54,076
2017	54,827
2018	55,681
2019	56,547
Thereafter	762,762
Total	1,038,652
Subleases [Member]
Operating Leased Assets [Line Items]
2015	2,428
2016	2,451
2017	2,480
2018	2,511
2019	2,542
Thereafter	34,273
Total	$46,685

Property_and_Equipment_Net_Com

Property and Equipment - Net - Components of Property Plant and Equipment (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$132,439	$41,146
Less accumulated depreciation and amortization	-30,525	-18,739
Property, plant and equipment - net	101,914	22,407
Vehicles [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	28,815	23,548
Computer hardware and software [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	28,724	7,381
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	5,501	2,653
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	13,992	7,397
Build-to-suit lease asset under construction
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	26,450
Manufacturing and lab equipment [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	21,677
Buildings [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	4,288
Land and land use rights [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	2,423
Other [Member]
Property Plant And Equipment [Line Items]
Property, plant and equipment, gross	$569	$167

Accrued_and_Other_Current_Liab2

Accrued and Other Current Liabilities - Schedule of Accrued and Other Current Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified
Payables And Accruals [Abstract]
Accrued compensation	$50,414	$21,634
Current portion of contingent consideration	41,978
Accrued expenses	27,485	19,943
Accrued sales and use taxes	10,438	5,229
Accrued warranty	8,607	7,502	4,019
Accrued professional services fees	6,813	4,031
Current portion of capital lease obligation	3,430	1,555
Current portion of deferred gain on sale-leaseback transactions	3,243	3,243
Amounts refundable to an investor		5,699
Income taxes payable		1,577
Current portion of participation interest		1,744
Total	$152,408	$72,157

Other_Liabilities_and_Deferred1

Other Liabilities and Deferred Credits - Summary of Other Liabilities and Deferred Credits (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Other Liabilities Disclosure [Abstract]
Deferred gain on sale-leaseback transactions, net of current portion	$54,790	$58,033
Build-to-suit lease liability	26,450
Deferred rent expense	4,838	3,333
Capital lease obligation	27,791	27,126
Liability for receipts from an investor	3,213	72,520
Contingent consideration	75,219
Participation interest	15,556	14,114
Other noncurrent liabilities	36,617	18,313
Total	$244,474	$193,439

Indebtedness_Summary_of_Debt_D

Indebtedness - Summary of Debt (Detail) (USD $)	0 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Oct. 31, 2013	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			$1,424,340	$535,692
Current, Carrying Value, Net of Fees			26,505	10,577
Long-Term, Carrying Value, Net of Fees			1,390,807	518,392
Unused Borrowing Capacity			273,085	410,885
2.75% Convertible senior notes due in 2018 [Member]
Debt Instrument [Line Items]
Maturity Date	1-Nov-18
1.625% Convertible senior notes due in 2019 [Member]
Debt Instrument [Line Items]
Maturity Date		1-Nov-19
Recourse debt [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			939,667	379,048
Current, Carrying Value, Net of Fees			3,797	1,789
Long-Term, Carrying Value, Net of Fees			932,809	373,263
Unused Borrowing Capacity			54,935	54,776
Recourse debt [Member] | Revolving credit facility [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			130,000	142,531
Long-Term, Carrying Value, Net of Fees			126,939	138,535
Unused Borrowing Capacity			54,935	54,776
Maturity Date			31-Dec-16	31-Dec-16
Interest Rate, Low			3.40%	3.40%
Interest Rate, High			3.40%	5.50%
Recourse debt [Member] | Vehicle loans [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			9,724	6,517
Current, Carrying Value, Net of Fees			2,647	1,789
Long-Term, Carrying Value, Net of Fees			7,077	4,728
Maturity Date, Start			31-Mar-15	31-Mar-15
Maturity Date, End			30-Jun-19	31-Dec-18
Interest Rate, Low			1.90%	0.00%
Interest Rate, High			7.50%	7.50%
Recourse debt [Member] | 2.75% Convertible senior notes due in 2018 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			230,000	230,000
Long-Term, Carrying Value, Net of Fees			230,000	230,000
Maturity Date			30-Nov-18	30-Nov-18
Interest Rate, Low			2.80%	2.80%
Interest Rate, High			2.80%	2.80%
Recourse debt [Member] | 1.625% Convertible senior notes due in 2019 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			566,000
Long-Term, Carrying Value, Net of Fees			566,000
Maturity Date			30-Nov-19
Interest Rate, Low			1.60%
Interest Rate, High			1.60%
Recourse debt [Member] | Solar Bonds [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			3,943
Current, Carrying Value, Net of Fees			1,150
Long-Term, Carrying Value, Net of Fees			2,793
Maturity Date, Start			31-Oct-15
Maturity Date, End			31-Oct-18
Interest Rate, Low			2.00%
Interest Rate, High			4.00%
Non-recourse debt [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			484,673	156,549
Current, Carrying Value, Net of Fees			22,708	8,693
Long-Term, Carrying Value, Net of Fees			457,998	145,129
Unused Borrowing Capacity			218,150	356,109
Non-recourse debt [Member] | Term loan assumed from Silevo acquisition [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			9,134
Current, Carrying Value, Net of Fees			9,134
Maturity Date			30-Jun-15
Interest Rate, Low			7.80%
Interest Rate, High			7.80%
Non-recourse debt [Member] | Term loan due in May 2016 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			34,195
Long-Term, Carrying Value, Net of Fees			33,497
Unused Borrowing Capacity			90,805
Maturity Date			31-May-16
Interest Rate, Low			3.20%
Interest Rate, High			3.20%
Non-recourse debt [Member] | Term loan due in December 2016 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			122,655
Long-Term, Carrying Value, Net of Fees			120,108
Unused Borrowing Capacity			127,345
Maturity Date			31-Dec-16
Interest Rate, Low			3.40%
Interest Rate, High			3.50%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2013-1 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			49,519	52,935
Current, Carrying Value, Net of Fees			3,291	3,155
Long-Term, Carrying Value, Net of Fees			46,228	49,780
Maturity Date			30-Nov-38	30-Nov-38
Interest Rate, Low			4.80%	4.80%
Interest Rate, High			4.80%	4.80%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2014-1 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			67,676
Current, Carrying Value, Net of Fees			2,779
Long-Term, Carrying Value, Net of Fees			64,897
Maturity Date			30-Apr-44
Interest Rate, Low			4.60%
Interest Rate, High			4.60%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2014-2 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value			201,494
Current, Carrying Value, Net of Fees			7,504
Long-Term, Carrying Value, Net of Fees			193,268
Maturity Date			31-Jul-44
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2014-2 [Member] | Class A [Member]
Debt Instrument [Line Items]
Interest Rate, Low			4.00%
Interest Rate, High			4.00%
Non-recourse debt [Member] | Solar Asset-backed Notes, Series 2014-2 [Member] | Class B [Member]
Debt Instrument [Line Items]
Interest Rate, Low			5.40%
Interest Rate, High			5.40%
Non-recourse debt [Member] | Working capital financing [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value				9,990
Current, Carrying Value, Net of Fees				1,197
Long-Term, Carrying Value, Net of Fees				8,793
Maturity Date				31-Dec-24
Interest Rate, Low				5.50%
Interest Rate, High				5.60%
Non-recourse debt [Member] | Credit facility for Solar Strong [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value				5,733
Current, Carrying Value, Net of Fees				149
Long-Term, Carrying Value, Net of Fees				5,297
Unused Borrowing Capacity				344,000
Maturity Date, Start				30-Jun-32
Maturity Date, End				31-Dec-32
Interest Rate, Low				6.80%
Interest Rate, High				7.30%
Non-recourse debt [Member] | Term loan due in June 2015 [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value				87,891
Current, Carrying Value, Net of Fees				4,192
Long-Term, Carrying Value, Net of Fees				81,259
Unused Borrowing Capacity				12,109
Maturity Date				30-Jun-15
Interest Rate, Low				3.40%
Interest Rate, High				3.70%
Other Debt [Member]
Debt Instrument [Line Items]
Unpaid Principal Balance, Carrying Value				95
Current, Carrying Value, Net of Fees				$95

Indebtedness_Additional_Inform

Indebtedness - Additional Information (Detail) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

1 Months Ended

0 Months Ended

Dec. 24, 2014

Dec. 24, 2014

Oct. 10, 2014

Jul. 31, 2014

Jul. 02, 2014

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Oct. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Oct. 31, 2014

Nov. 30, 2013

Jul. 31, 2014

Mar. 20, 2014

Jan. 06, 2014

Nov. 21, 2011

Sep. 23, 2014

Feb. 20, 2014

Feb. 04, 2014

23-May-14

26-May-10

Jun. 07, 2013

Sep. 30, 2012

Debt Instrument [Line Items]

Convertible senior notes aggregate principal amount

$66,000,000

Convertible senior notes issued date

10-Oct-14

Capped call option agreement notional amount

65,203,000

0

0

Loss on extinguishment of long-term debt

2,600,000

1,500,000

400,000

4,533,000

306,000

0

Credit facility settlement amount

5,500,000

Subsidiary [Member]

Debt Instrument [Line Items]

Maximum amount to be borrowed under financing agreement

350,000,000

2.75% Convertible senior notes due in 2018 [Member]

Debt Instrument [Line Items]

Convertible senior notes aggregate principal amount

230,000,000

Proceeds from convertible debt

222,500,000

Debt instrument maturity date

1-Nov-18

Loan facility interest rate

2.75%

Convertible senior notes conversion amount

1,000

Convertible senior notes number of equity instrument for each $1,000 of principal

16.2165

Convertible senior notes conversion price

$61.67

Convertible senior notes, description

The convertible senior notes do not have a cash conversion option. The convertible senior note holders may require the Company to repurchase their convertible senior notes for cash only under certain defined fundamental changes.

2.75% Convertible senior notes due in 2018 [Member] | Maximum [Member]

Debt Instrument [Line Items]

Convertible senior notes number of equity instrument for each $1,000 of principal

21.4868

2.75% Convertible senior notes due in 2018 [Member] | Minimum [Member]

Debt Instrument [Line Items]

Convertible senior notes conversion price

$46.54

1.625% Convertible senior notes due in 2019 [Member]

Debt Instrument [Line Items]

Proceeds from convertible debt

64,500,000

Debt instrument maturity date

1-Nov-19

Loan facility interest rate

1.63%

Convertible senior notes conversion amount

1,000

Convertible senior notes conversion price

$83.53

Convertible senior notes, description

The convertible senior notes do not have a cash conversion option. The convertible senior note holders may require the Company to repurchase their convertible senior notes for cash only under certain defined fundamental changes.

Convertible senior notes number of equity instrument for each $1,000 of principal

11.972

Capped call option agreement notional amount

7,600,000

57,600,000

Cap price

126.08

126.08

Initial strike price

83.53

83.53

1.625% Convertible senior notes due in 2019 [Member] | Public Offering

Debt Instrument [Line Items]

Convertible senior notes aggregate principal amount

500,000,000

Proceeds from convertible debt

488,300,000

1.625% Convertible senior notes due in 2019 [Member] | Maximum [Member]

Debt Instrument [Line Items]

Convertible senior notes number of equity instrument for each $1,000 of principal

15.8629

Derivative, Expiry date

29-Oct-19

1.625% Convertible senior notes due in 2019 [Member] | Minimum [Member]

Debt Instrument [Line Items]

Convertible senior notes conversion price

$63.04

Derivative, Expiry date

4-Sep-19

Solar Bond Program [Member]

Debt Instrument [Line Items]

Borrowed funds, base interest rate

2.00%

Interest Rate, High

4.00%

Solar Bond Program [Member] | Maximum [Member]

Debt Instrument [Line Items]

Debt instrument interest rate term range

7 years

Solar Bond Program [Member] | Minimum [Member]

Debt Instrument [Line Items]

Debt instrument interest rate term range

1 year

Term loan assumed from Silevo acquisition [Member] | February 4, 2014 agreement [Member]

Debt Instrument [Line Items]

Maximum amount to be borrowed under financing agreement

250,000,000

220,000,000

100,000,000

Debt Instrument, interest rate terms

Company’s option, 3.25% plus the highest of (i) the Federal Funds Rate plus 0.50%, (ii) Bank of America’s published “prime rate” or (iii) LIBOR plus 1.00%.

Term loan assumed from Silevo acquisition [Member] | Silevo, Inc [Member]

Debt Instrument [Line Items]

Loan facility interest rate

7.80%

Acquired term loan

9,100,000

Term loan due in December 2016 [Member] | May 23, 2014 agreement [Member]

Debt Instrument [Line Items]

Maximum amount to be borrowed under financing agreement

125,000,000

Debt Instrument, interest rate terms

Company’s option, plus the highest of (i) the Federal Funds Rate plus 0.50%, (ii) Bank of America’s published “prime rate” or (iii) LIBOR plus 1.00%.

Term loan due in December 2016 [Member] | Maximum [Member] | May 23, 2014 agreement [Member]

Debt Instrument [Line Items]

Loan facility interest rate

4.00%

Term loan due in December 2016 [Member] | Minimum [Member] | May 23, 2014 agreement [Member]

Debt Instrument [Line Items]

Loan facility interest rate

3.00%

Solar Asset-backed Notes, Series 2013-1 [Member]

Debt Instrument [Line Items]

Convertible senior notes aggregate principal amount

54,400,000

Value Solar assets

143,900,000

Debt discount percentage

0.05%

Lease pass-through financing obligation [Member]

Debt Instrument [Line Items]

Lease financing obligations

56,400,000

Lease financing obligation termination

40,200,000

Lease pass-through financing obligation [Member] | VIE, primary beneficiary [Member]

Debt Instrument [Line Items]

Lease financing obligation termination

74,500,000

Solar Asset-backed Notes, Series 2014-1 [Member]

Debt Instrument [Line Items]

Convertible senior notes aggregate principal amount

134,400,000

134,400,000

70,200,000

Debt discount percentage

0.01%

Solar Asset-backed Notes, Series 2014-2 [Member]

Debt Instrument [Line Items]

Convertible senior notes aggregate principal amount

285,600,000

Debt discount percentage

0.01%

Solar Asset-backed Notes, Series 2014-2 [Member] | Class A [Member]

Debt Instrument [Line Items]

Convertible senior notes aggregate principal amount

160,000,000

160,000,000

Solar Asset-backed Notes, Series 2014-2 [Member] | Class B [Member]

Debt Instrument [Line Items]

Convertible senior notes aggregate principal amount

41,500,000

41,500,000

Solar Asset-backed Notes, Series 2014-2 [Member] | June 7, 2013 agreement [Member]

Debt Instrument [Line Items]

Settlement of term loan

129,300,000

LIBOR [Member] | Term loan assumed from Silevo acquisition [Member] | February 4, 2014 agreement [Member]

Debt Instrument [Line Items]

Basis interest rate

3.25%

Working Capital Financing [Member]

Debt Instrument [Line Items]

Maximum amount to be borrowed under financing agreement

16,300,000

Basis interest rate

2.00%

Debt Instrument, interest rate terms

Each tranche bore interest at an annual rate of 2.00% plus the swap rate applicable to the average life of the scheduled lease receipts for the tranche.

Number of funded tranches

4

Term Loans [Member] | Term loan due in June 2015 [Member] | June 7, 2013 agreement [Member]

Debt Instrument [Line Items]

Maximum amount to be borrowed under financing agreement

158,000,000

100,000,000

Credit facility interest rate terms

LIBOR plus 3.25

Term Loans [Member] | LIBOR [Member] | Term loan due in June 2015 [Member] | June 7, 2013 agreement [Member]

Debt Instrument [Line Items]

Basis interest rate

3.25%

Syndicated revolving bank agreement [Member] | Revolving credit facility [Member]

Debt Instrument [Line Items]

Maximum amount to be borrowed under financing agreement

$200,000,000

$75,000,000

Credit facility interest rate terms

The Company entered into a revolving credit agreement with a syndicate of banks to obtain funding for working capital, letters of credit and funding for general corporate needs. The committed amount under the revolving credit facility was increased from $75.0 million to $200.0 million in 2013. Borrowed funds bear interest, at the Company’s option, at an annual rate of (a) 3.25% plus LIBOR or (b) 2.25% plus the highest of (i) the federal funds rate plus 0.50%, (ii) Bank of America’s published “prime rate” or (iii) LIBOR plus 1.00%.

Percentage of fee for undrawn commitments

0.38%

Borrowed funds, base interest rate

2.25%

Syndicated revolving bank agreement [Member] | Revolving credit facility [Member] | LIBOR [Member]

Debt Instrument [Line Items]

Basis interest rate

3.25%

Syndicated revolving bank agreement [Member] | Revolving credit facility [Member] | Federal Funds Rate [Member]

Debt Instrument [Line Items]

Basis interest rate

0.50%

Syndicated revolving bank agreement [Member] | Revolving credit facility [Member] | LIBOR Option 2 [Member]

Debt Instrument [Line Items]

Basis interest rate

1.00%

Indebtedness_Schedule_of_Princ

Indebtedness - Schedule of Principal Maturities of Debt (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]
2015	$26,520
2016	302,992
2017	17,051
2018	246,768
2019	580,899
Thereafter	250,110
Total	1,424,340	535,692
Recourse Debt Excluding Convertible Senior Notes [Member]
Debt Instrument [Line Items]
2015	3,787
2016	133,137
2017	3,442
2018	2,876
2019	425
Total	143,667
Non-recourse debt [Member]
Debt Instrument [Line Items]
2015	22,733
2016	169,855
2017	13,609
2018	13,892
2019	14,474
Thereafter	250,110
Total	484,673	156,549
Convertible senior notes [Member]
Debt Instrument [Line Items]
2018	230,000
2019	566,000
Total	$796,000

VIE_Fund_Arrangements_Addition

VIE Fund Arrangements - Additional Information (Detail) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2014
Fund Investor [Abstract]
Investors contribution to variable interest equity		$1,683
Total consideration paid	0.5
Accrued in distribution payable		$2.70

VIE_Fund_Arrangements_Summary_

VIE Fund Arrangements - Summary of Number of Fund by Type of Investor and the Carrying Value (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Variable Interest Entity [Line Items]
Carrying Value of Solar Energy System	$2,796,796	$1,682,521
VIEs [Member]
Variable Interest Entity [Line Items]
Number Of Funds	24
Carrying Value of Solar Energy System	1,581,459	759,148
Financial Institutions [Member] | VIEs [Member]
Variable Interest Entity [Line Items]
Number Of Funds	16
Carrying Value of Solar Energy System	1,174,120
Corporations [Member] | VIEs [Member]
Variable Interest Entity [Line Items]
Number Of Funds	5
Carrying Value of Solar Energy System	148,931
Utilities [Member] | VIEs [Member]
Variable Interest Entity [Line Items]
Number Of Funds	2
Carrying Value of Solar Energy System	252,836
Various Other Investors [Member] | VIEs [Member]
Variable Interest Entity [Line Items]
Number Of Funds	1
Carrying Value of Solar Energy System	$5,572

VIE_Fund_Arrangements_Carrying

VIE Fund Arrangements - Carrying Values of Assets and Liabilities of Subsidiary in Consolidated Balance Sheets (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Restricted cash	$20,875	$19,182
Accounts receivable - net	22,708	23,011
Total current assets	1,002,399	787,663
Solar energy systems, leased and to be leased - net	2,796,796	1,682,521
Other assets	111,001	38,774
Current liabilities:
Distributions payable to noncontrolling interests and redeemable noncontrolling interests	8,552	20,390
Current portion of deferred U.S. Treasury grant income	15,330	15,340
Customer deposits	10,560	8,828
Current portion of deferred revenue	86,238	59,899
Total current liabilities	567,091	338,206
Deferred revenue, net of current portion	557,408	410,161
Deferred U.S. Treasury grant income, net of current portion	397,500	412,500
Other liabilities and deferred credits	244,474	193,439
VIEs [Member]
Current assets:
Cash and cash equivalents	26,419	35,141
Restricted cash	106	115
Accounts receivable - net	6,769	4,802
Rebates receivable	25,397	17,351
Prepaid expenses and other current assets	615	3,831
Total current assets	59,306	61,240
Restricted cash	300
Solar energy systems, leased and to be leased - net	1,581,459	759,148
Other assets	3,780	2,777
Total assets	1,644,845	823,165
Current liabilities:
Distributions payable to noncontrolling interests and redeemable noncontrolling interests	8,552	20,390
Current portion of deferred U.S. Treasury grant income	6,502	6,668
Accrued and other current liabilities	336	615
Customer deposits	6,405	5,291
Current portion of deferred revenue	16,746	13,754
Current portion of bank borrowings		251
Total current liabilities	38,541	46,969
Deferred revenue, net of current portion	256,200	206,324
Bank borrowings, net of current portion		5,482
Deferred U.S. Treasury grant income, net of current portion	170,548	180,566
Other liabilities and deferred credits	10,825	1,893
Total liabilities	$476,114	$441,234

Lease_PassThrough_Financing_Ob2

Lease Pass-Through Financing Obligation - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
	Arrangements
Property Subject To Or Available For Operating Lease [Line Items]
Number of lease pass-through fund arrangements	8
Initial lease term	20 years
Depreciation on lease	$159,160,000	$86,457,000
Capital lease obligation	27,791,000	27,126,000
Current portion of capital lease obligation	3,430,000	1,555,000
Solar Energy Systems Under Lease Pass-through Fund Arrangements [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Cost of lease	540,000,000	420,400,000
Depreciation on lease	34,100,000	17,600,000
Capital lease obligation	88,700,000	93,200,000
Current portion of capital lease obligation	$29,200,000	$29,000,000
Minimum [Member] | Solar Energy Systems Under Lease Pass-through Fund Arrangements [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Initial lease term	10 years
Maximum [Member] | Solar Energy Systems Under Lease Pass-through Fund Arrangements [Member]
Property Subject To Or Available For Operating Lease [Line Items]
Initial lease term	25 years

Lease_PassThrough_Financing_Ob3

Lease Pass-Through Financing Obligation - Summary of Future Minimum Lease Payments to be Received from Investors (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Property Subject To Or Available For Operating Lease [Line Items]
2015	$54,759
2016	54,076
2017	54,827
2018	55,681
2019	56,547
Thereafter	762,762
Total	1,038,652
Investors [Member]
Property Subject To Or Available For Operating Lease [Line Items]
2015	24,216
2016	23,857
2017	23,989
2018	24,070
2019	24,023
Thereafter	76,468
Total	$196,623

SaleLeaseback_Arrangements_Add

Sale-Leaseback Arrangements - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2014	Dec. 31, 2013
Sale Leaseback Transaction [Line Items]
Master leaseback arrangement term	15 years	10 years
Value of assets sold to investor under leaseback arrangement	$25,200,000
Cost of assets contributed to subsidiary		44,600,000	44,600,000
Proceeds from sale of assets under fund arrangement		100,000,000
Sales-leaseback arrangements, amounts due to investors		0
Sale-leaseback Arrangement [Member]
Sale Leaseback Transaction [Line Items]
Restricted cash	1,250,000
Reduction in restricted cash	$250,000

SaleLeaseback_Financing_Obliga2

Sale-Leaseback Financing Obligation - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2014	Dec. 31, 2013
Sale Leaseback Transaction [Line Items]
Gross cash consideration from lease agreement		$27,200,000
Net cash consideration from lease agreement		3,500,000	23,700,000
Interest rate of sale-leaseback agreement		4.37%
Lease term	15 years	10 years
Sale-leaseback financing obligation outstanding		14,300,000	14,800,000
Current portion of sale-leaseback financing obligation		448,000	418,000
Sale-leaseback financing obligation, net of current portion		13,889,000	14,338,000
Restricted cash		20,875,000	19,182,000
Sale-Leaseback Financing Obligation [Member]
Sale Leaseback Transaction [Line Items]
Restricted cash escrow		1,250,000
Reduction in restricted cash		250,000
Restricted cash		$250,000
Sale Leaseback Solar Energy System Asset [Member]
Sale Leaseback Transaction [Line Items]
Property and equipment, Useful Lives		30 years
Minimum [Member]
Sale Leaseback Transaction [Line Items]
Lease extension period		2 years
Maximum [Member]
Sale Leaseback Transaction [Line Items]
Lease extension period		6 years

SaleLeaseback_Financing_Obliga3

Sale-Leaseback Financing Obligation - Schedule of Future Minimum Annual Rentals to Be Received from Customers (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Leases [Abstract]
2015	$475
2016	485
2017	494
2018	504
2019	514
Thereafter	2,728
Total	$5,200

SaleLeaseback_Financing_Obliga4

Sale-Leaseback Financing Obligation - Schedule of Future Minimum Annual Lease Payments to Investor under Financing Arrangement (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Leases [Abstract]
2015	$1,257
2016	1,264
2017	1,270
2018	1,277
2019	1,284
Total	$6,352

Redeemable_Noncontrolling_Inte2

Redeemable Noncontrolling Interests in Subsidiaries - Activity of Redeemable Noncontrolling Interests in Subsidiaries (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Redeemable Noncontrolling Interest [Line Items]
Beginning balance	$804,415	$280,394	$62,676
Contributions from noncontrolling interests	517,471	189,779	115,133
Net loss	-375,230	-151,758	-113,726
Distributions to noncontrolling interests	-90,974	-122,641	-95,591
Transfers from noncontrolling interests in subsidiaries	25,248
Ending balance	1,155,584	804,415	280,394
Redeemable Noncontrolling Interests [Member]
Redeemable Noncontrolling Interest [Line Items]
Beginning balance	44,709	12,827	22,308
Contributions from noncontrolling interests	260,492	172,913	46,293
Net loss	-141,072	-118,854	8,696
Distributions to noncontrolling interests	-14,313	-22,726	-54,714
Transfers from noncontrolling interests in subsidiaries	25,248
Redeemable noncontrolling interests arising from acquisition of Silevo	14,174	549
Acquisition of redeemable noncontrolling interests in subsidiaries	-2,450		-9,756
Ending balance	$186,788	$44,709	$12,827

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	0 Months Ended			12 Months Ended			0 Months Ended
	Sep. 23, 2014	Oct. 21, 2013	Dec. 20, 2012	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 06, 2013	Dec. 11, 2013	Jun. 30, 2006	Dec. 18, 2012
Schedule Of Capitalization Equity [Line Items]
Common stock, shares issued				96,521,000	96,521,000				4,000,000
Common stock, par value				$0.00	$0.00				$0.00
Conversion of stock, shares				8,372,065
Proceeds from issuance of common stock net of underwriters discounts and commissions and offering costs			$92,400,000
Underwriters discounts and commissions and offering costs			12,900,000
Common stock issued for acquisition	2,284,070
Issuance of common stock from public offering, shares		3,910,000
Proceeds from issuance of common stock		$174,100,000		$0	$174,083,000	$92,386,000
Paramount Energy [Member]
Schedule Of Capitalization Equity [Line Items]
Common stock issued for acquisition							3,674,565
Zep Solar [Member]
Schedule Of Capitalization Equity [Line Items]
Common stock issued for acquisition								2,751,782
Closing of initial public offering [Member]
Schedule Of Capitalization Equity [Line Items]
Common stock, shares issued			1,725,000							11,434,988
Common stock, par value			$8							$8
Conversion of stock, shares				50,400,000
Conversion of preferred stock into common stock date				18-Dec-12

Stockholders_Equity_Schedule_o

Stockholders' Equity - Schedule of Reserved Shares of Common Stock for Future Issuance (Detail)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Awards available for grant	7,919	8,466
Awards outstanding	14,979	13,969
Total	38,118	28,677
Employee Stock Purchase Plan [Member]
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Employee Stock Purchase Plan	1,300	1,300
Convertible senior notes [Member]
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Convertible senior notes outstanding	13,920	4,942

Equity_Award_Plans_Additional_

Equity Award Plans - Additional Information (Detail) (USD $)	12 Months Ended				1 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Granted stock options at fair market value on grant date	not less than 100%
Holding percent of stockholder	10.00%
Exercisable options granted	10 years
Percentage of outstanding stock options, before vested and exercisable	27.00%
Grant date fair market value of options that vested	$54,900,000	$28,300,000	$13,300,000
Total unrecognized stock-based compensation , net of estimated forfeitures	242,900,000	103,000,000
Weighted-average period	2 years 9 months 4 days	2 years 8 months 27 days
Weighted-average exercise period	7 years 7 months 21 days	7 years 6 months 7 days	7 years 8 months 1 day	8 years 2 months 19 days
Stock-based compensation expense	88,900,000	27,900,000	11,200,000
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total unrecognized stock-based compensation , net of estimated forfeitures	55,200,000	500,000
Grant date fair value of RSUs released	3,200,000	400,000
Weighted-average exercise period	3 years 3 months 18 days	1 year 11 months 27 days
Zep Solar [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option grant to purchase shares of common stock	303,151
Grant date fair market value of options that vested	$14,900,000
Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price as percentage of fair value per share on the grant date	100.00%
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercisable options granted	4 years
10% or greater stockholder [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Exercise price as percentage of fair value per share on the grant date	110.00%
Initial appointment [Member] | Nonemployee director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option grant to purchase shares of common stock					30,000
Additional stock options [Member] | Nonemployee director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option grant to purchase shares of common stock					15,000
Annual cash retainer [Member] | Nonemployee director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock option grant to purchase shares of common stock					15,000

Equity_Award_Plans_Summary_of_

Equity Award Plans - Summary of Stock Option Activity (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Stock Options, Outstanding, Balance	13,949	14,903	13,873
Stock Options, Granted	5,544	4,364	3,082
Stock Options, Exercised	-3,176	-4,260	-902
Stock Options, Canceled	-2,367	-1,361	-1,150
Stock Options, Outstanding, Balance	13,950	13,949	14,903	13,873
Stock Options, Issued in connection with a business acquisition		303
Stock Options, Vested and exercisable	6,537	6,696	7,374
Stock Options, Vested and expected to vest	12,423	12,828	13,940
Weighted-Average Exercise Price, Outstanding, Balance	$14.77	$4.80	$3.28
Weighted-Average Exercise Price, Granted	$65.69	$39.02	$11.08
Weighted-Average Exercise Price, Exercised	$6.38	$3.65	$1.91
Weighted-Average Exercise Price, Canceled	$38.51	$15.30	$5.55
Weighted-Average Exercise Price, Outstanding, Balance	$32.89	$14.77	$4.80	$3.28
Weighted-Average Exercise Price, Exercised, Issued in connection with acquisition		$1.97
Weighted-Average Exercise Price, Options vested and exercisable	$12.72	$4.62	$2.73
Weighted-Average Exercise Price, Options vested and expected to vest	$30.15	$13.53	$4.61
Weighted-Average Remaining Contractual Term, Outstanding	7 years 7 months 21 days	7 years 6 months 7 days	7 years 8 months 1 day	8 years 2 months 19 days
Weighted-Average Remaining Contractual Term, Options vested and exercisable	6 years 3 months 18 days	6 years 6 months 15 days	6 years 10 months 21 days
Weighted-Average Remaining Contractual Term, Options vested and expected to vest	7 years 5 months 16 days	7 years 4 months 28 days	7 years 7 months 6 days
Aggregate Intrinsic Value, Outstanding, Balance	$586,740	$107,653	$37,606
Aggregate Intrinsic Value, Exercised	185,822	149,653	9,000
Aggregate Intrinsic Value, Outstanding, Balance	342,293	586,740	107,653	37,606
Aggregate Intrinsic Value, Options vested and exercisable	272,140	349,523	67,864
Aggregate Intrinsic Value, Options vested and expected to vest	$333,813	$555,412	$103,187

Equity_Award_Plans_Summary_of_1

Equity Award Plans - Summary of Stock Option Activity (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Roll Forward
Weighted-average fair value, Granted	$47.45	$27.55	$11.08
Weighted-average fair value, issued in connection with a business acquisition		$49.13

Equity_Award_Plans_Summary_of_2

Equity Award Plans - Summary of Fair Value of Stock Options Granted Using Weighted-Average Assumptions (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Dividend yield	0.00%	0.00%	0.00%
Annual risk-free rate of return	1.95%	1.45%	1.07%
Expected volatility	83.66%	92.86%	89.52%
Expected term (years)	6 years 3 months	6 years 22 days	6 years 2 months 9 days

Equity_Award_Plans_Summary_of_3

Equity Award Plans - Summary of RSU Activity (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Restricted Stock Activity [Line Items]
Weighted-average fair value, issued in connection with a business acquisition		$49.13
Restricted Stock Units [Member]
Schedule Of Restricted Stock Activity [Line Items]
Restricted Stock Units, Outstanding, Beginning balance	20	17
Restricted Stock Units, Granted	1,097	17	17
Restricted Stock Units, Outstanding, Ending balance	1,029	20	17
Restricted Stock Units, Released	-52	-14
Restricted Stock Units, Cancelled	-36
Restricted Stock Units, Expected to vest - December 31, 204	776
Weighted-Average Fair Value, Outstanding, Beginning balance	$25.46	$18.48
Weighted-Average Fair Value, Granted	$61.92	$35	$18.48
Weighted-Average Fair Value, Outstanding, Ending balance	$61.16	$25.46	$18.48
Weighted-average fair value, issued in connection with a business acquisition	$60.81	$50.18
Weighted-Average Fair Value, Cancelled	$64.79
Weighted-Average Fair Value, Expected to vest - December 31, 2014	$61.45

Equity_Award_Plans_Summary_of_4

Equity Award Plans - Summary of Stock-Based Compensation Expense Capitalized (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Inventories [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, amounts capitalized	$192	$433	$318
Prepaid Expenses and Other Current Assets [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, amounts capitalized	4
Other Assets [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, amounts capitalized	138
Property, Plant and Equipment - Net [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, amounts capitalized	5,340
Solar Energy Systems
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation, amounts capitalized	$17,700	$6,576	$2,423

Equity_Award_Plans_Summary_of_5

Equity Award Plans - Summary of Stock-Based Compensation Expense Recognized (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$88,900	$27,900	$11,200
Cost of revenue [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	2,251	741	470
Sales and marketing [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	16,391	4,003	1,316
General and administrative [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	40,897	15,914	6,652
Research and development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation expense	$6,023	$269

Income_Taxes_Components_of_Dom

Income Taxes - Components of Domestic and Foreign (Loss) Income before Income Taxes (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
United States	($718,416)	($272,603)	($128,119)
Noncontrolling interest and redeemable noncontrolling interests	319,196	95,968	14,391
Foreign	-2,746	78	56
Total	($401,966)	($176,557)	($113,672)

Income_Taxes_Schedule_of_Incom

Income Taxes - Schedule of Income Tax (Benefit) Provision (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current:
Federal	$10	$10	$10
State	473	80	16
Foreign	100	26	15
Total Current Provision	583	116	41
Deferred:
Federal	-26,528	-22,691	12
State	-791	-2,224	1
Total Deferred Provision	-27,319	-24,915	13
Total (benefit) provision for income taxes	($26,736)	($24,799)	$54

Income_Taxes_Schedule_of_Recon

Income Taxes - Schedule of Reconciliation of Effective Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Tax benefit at federal statutory rate	-34.00%	-34.00%	-34.00%
State income taxes (net of federal benefit)	-1.71%	-0.88%	-1.43%
Foreign income and withholding taxes	0.44%	1.41%	0.00%
Noncontrolling interests and redeemable noncontrolling interests adjustment	5.18%	-16.62%	-32.03%
Investment in certain financing funds	16.49%	36.20%	35.84%
Stock-based compensation	2.35%	1.77%	2.07%
ASC 810 prepaid tax expense	-5.45%	-1.39%	0.00%
Purchase accounting adjustment	0.00%	0.00%	21.24%
Other	1.24%	-3.74%	1.05%
Tax Credits	-1.49%	-1.75%	0.00%
Change in valuation allowance	10.30%	4.96%	7.30%
Effective tax rate	-6.65%	-14.04%	0.04%

Income_Taxes_Schedule_of_Defer

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Jun. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Deferred tax assets:
Accruals and reserves	$29,142		$12,693
Net operating losses	86,322		119,790
Accelerated gain on assets	25,710		27,712
Investment in certain financing funds	288,556		69,273
Tax rebate revenue	41,710		47,360
Stock-based compensation	21,769		5,873
Other deferred tax assets	5,507		1,924
Tax credits	10,849		4,577
Gross deferred tax assets	509,565		289,202
Valuation allowance	-111,222		-59,902
Net deferred tax assets	398,343		229,300
Deferred tax liabilities:
Depreciation and amortization	-239,170	-1,600	-125,765
Investment in certain financing funds	-86,518		-69,203
Initial direct costs related to customer solar energy system lease acquisition costs and Other deferred tax liabilities	-72,700		-33,725
Gross deferred tax liabilities	-398,388		-228,693
Net deferred taxes	($45)		$607

Income_Taxes_Schedule_of_Curre

Income Taxes - Schedule of Current and Noncurrent Deferred Tax Assets and Liabilities (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current:
Deferred tax assets	$17,381	$12,940
Less: valuation allowance	-4,232	-3,095
Net current deferred tax assets	13,149	9,845
Noncurrent:
Deferred tax assets	488,043	274,588
Deferred tax liabilities	-394,247	-227,021
Total noncurrent gross deferred tax assets	93,796	47,567
Less: valuation allowance	-106,990	-56,805
Net noncurrent deferred tax liabilities	($13,194)	($9,238)

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	6 Months Ended	12 Months Ended			0 Months Ended	1 Months Ended
	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 11, 2013	Sep. 30, 2014	Oct. 31, 2013
Income Tax Contingency [Line Items]
Acquisition of Silevo		$115,319,000
Goodwill		315,920,000	148,879,000	626,000			148,879,000
Long-term deferred tax liability		13,194,000	9,238,000
Increase (Decrease) in valuation allowance		51,300,000	1,900,000
Ownership interest percentage				100.00%
Taxable income resulting from liquidating distributions				0
Deferred tax liability, accelerated depreciation for tax purposes	1,600,000	239,170,000	125,765,000
Net income tax expense after valuation allowance applied	0
Interest and penalties accrued for uncertain tax positions		0	0
Unrecognized tax benefits, increase (decrease) from uncertain tax position		0
Solar energy systems leased and to be leased [Member]
Income Tax Contingency [Line Items]
Property and equipment, Useful Lives		30 years
Other non-current asset
Income Tax Contingency [Line Items]
Long-term prepaid tax expense			3,700,000	3,700,000
Zep Solar [Member]
Income Tax Contingency [Line Items]
Acquisition of Silevo			157,800,000		157,823,000
Acquisition of intangible assets			86,000,000
Goodwill			97,801,000
Weighted-average life of intangible assets		7 years
Long-term deferred tax liability			24,800,000
Increase (Decrease) in valuation allowance			-24,800,000
Silevo, Inc. [Member]
Income Tax Contingency [Line Items]
Acquisition of Silevo						270,900,000
Acquisition of intangible assets						119,000,000
Goodwill						167,000,000
Weighted-average life of intangible assets						10 years
Long-term deferred tax liability						27,300,000
Federal tax credit [Member]
Income Tax Contingency [Line Items]
Investment tax credit carryforward, limitation on use		Begins to expire in 2028 if not utilized
Federal [Member]
Income Tax Contingency [Line Items]
NOL carryforwards		439,800,000	419,800,000
NOL carryforwards, limitation on use		Expire at various dates beginning in 2026 if not utilized
Federal [Member] | Federal tax credit [Member]
Income Tax Contingency [Line Items]
Tax credit carryforwards		7,200,000	1,600,000
California [Member]
Income Tax Contingency [Line Items]
NOL carryforwards		228,400,000	186,100,000
NOL carryforwards, limitation on use		Expire at various dates beginning in 2020 if not utilized
Tax credit carryforwards		1,600,000	200,000
Other state [Member]
Income Tax Contingency [Line Items]
NOL carryforwards		77,700,000	77,200,000
Federal, California and other state [Member]
Income Tax Contingency [Line Items]
NOL carryforwards		229,500,000
Federal, California and other state [Member] | Windfall stock option deduction [Member]
Income Tax Contingency [Line Items]
NOL carryforwards		229,500,000	109,200,000
Foreign country [Member]
Income Tax Contingency [Line Items]
NOL carryforwards, limitation on use		Begins to expire in 2023 if not utilized
Tax credit carryforwards		$2,200,000	$2,500,000

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Balance, January 1	$120
Acquired from ZepSolar	434	120
Balance, December 31	531	120
True-up to prior year ending balance	($23)

Defined_Contribution_Plan_Addi

Defined Contribution Plan - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation And Retirement Disclosure [Abstract]
Contributions to Retirement Plan	$0	$0	$0

Related_Party_Transactions_Com

Related Party Transactions - Components of Related Party Transactions (Detail) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue:
Solar energy systems sales to related parties	$2,479	$17	$937
Expenditures:
Purchases of inventories from related parties	3,383	1,741
Fees paid or payable to related parties (included in sales and marketing expense)	103	81
Interest paid or payable to related parties (included in interest expense — net)	$3

Related_Party_Transactions_Sum

Related Party Transactions - Summary of Related Party Balances (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Related Party Transactions [Abstract]
Due from related parties (included in accounts receivable)	$30	$9
Due to related parties (included in accounts payable)	300	427
Due to related parties (included in customer deposits)		83
Due to related parties (included in long-term debt)	530
Due to related parties (included in accrued and other current liabilities)	3
Deferred revenue from related parties (included in current portion of deferred revenue)		$831

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	0 Months Ended	12 Months Ended			1 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2014
					acre
					sqft
Long Term Purchase Commitment [Line Items]
Aggregate rent expense for facilities and equipment		$32,900,000	$13,800,000	$4,200,000
Initial direct costs related to solar energy systems leased to customers		20 years
Property, plant and equipment - net	101,914,000	101,914,000	22,407,000
Letters of credit outstanding	15,100,000	15,100,000
Letters of credit, fee percentage	3.38%
Law suit filing date		28-Mar-14
Minimum [Member]
Long Term Purchase Commitment [Line Items]
Initial direct costs related to solar energy systems leased to customers		10 years
Build-to-suit lease arrangement | Construction in Progress [Member]
Long Term Purchase Commitment [Line Items]
Property, plant and equipment - net	26,500,000	26,500,000
Build-to-suit lease arrangement | Research Foundation
Long Term Purchase Commitment [Line Items]
Area of manufacturing facility					1,000,000
Number of acres producing solar panels					88.24
Construction cost committed					350,000,000
Acquisition of manufacturing equipment					400,000,000
Initial direct costs related to solar energy systems leased to customers		10 years
Operating Lease, Option to Renew Amount per Year					1
Operating Lease, Initial Lease Term Amount					0
Contractual Obligation					41,200,000
Lease Arrangement, Amount Required to Spend or Incur					$5,000,000,000
Build-to-suit lease arrangement | Research Foundation | Minimum [Member]
Long Term Purchase Commitment [Line Items]
Capacity to Produce Solar Panels					1

Commitments_and_Contingencies_2

Commitments and Contingencies - Future Minimum Lease Payments under Noncancelable Leases (Detail) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]
2015	$26,432
2016	23,172
2017	19,451
2018	13,835
2019	11,472
Thereafter	44,860
Total minimum lease payments	$139,222

Basic_and_Diluted_Net_Loss_Per2

Basic and Diluted Net Loss Per Share - Computation of Company's Basic and Diluted Net Loss Per Share (Detail) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Net loss attributable to stockholders	($56,034)	($55,790)	($99,335)
Net loss attributable to common stockholders, basic	-56,034	-55,790	-109,426
Adjustment to revaluation of convertible redeemable preferred stock warrants			-277
Net loss attributable to common stockholders, diluted	-56,034	-55,790	-109,703
Basic	93,333,880	79,781,976	14,240,187
Diluted	93,333,880	79,781,976	14,267,767
Net loss per share attributable to common stockholders, basic	($0.60)	($0.70)	($7.68)
Net loss per share attributable to common stockholders, diluted	($0.60)	($0.70)	($7.69)
Series G convertible redeemable preferred stock [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Deemed dividend to Series G convertible redeemable preferred stock prior to conversion			($10,091)
Convertible redeemable preferred stock [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Weighted-average of dilutive convertible redeemable preferred stock warrants outstanding			27,580

Basic_and_Diluted_Net_Loss_Per3

Basic and Diluted Net Loss Per Share - Computation of Company's Basic and Diluted Net Loss Per Share (Parenthetical) (Detail) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2006	Mar. 12, 2012	Jan. 31, 2012
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Conversion of stock, shares	8,372,065
Common stock, par value	$0.00	$0.00	$0.00
Series G convertible redeemable preferred stock [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Common stock, par value				$10.93	$10.84
Original issue price per share	$23.92
Percentage of initial public offering	60.00%
Number of preferred stock issued	3,386,986
Series F convertible redeemable preferred stock [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Original issue price per share	$9.68
Common stock undefined [Member] | Series G convertible redeemable preferred stock [Member]
Schedule Of Earnings Per Share Basic And Diluted [Line Items]
Common stock, par value	$8

Basic_and_Diluted_Net_Loss_Per4

Basic and Diluted Net Loss Per Share - Schedule of Outstanding Shares of Common Stock Equivalents Excluded from Computation of Diluted Net Loss Per Share (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Convertible redeemable preferred stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from the computation of diluted net income (loss) per share			42,488,627
Preferred stock warrants and common stock warrants [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from the computation of diluted net income (loss) per share		516,702	835,698
Common stock options [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from the computation of diluted net income (loss) per share	14,332,220	14,412,968	14,623,766
Restricted Stock Units [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from the computation of diluted net income (loss) per share	341,598	21,681
Convertible debt securities [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common stock equivalents excluded from the computation of diluted net income (loss) per share	5,434,673	735,740

Subsequent_Events_Additional_I

Subsequent Events - Additional Information (Detail) (Subsequent Event, USD $)	1 Months Ended	0 Months Ended
	Feb. 28, 2015	Jan. 09, 2015
	Fund
Subsequent Event [Line Items]
Number of new financing funds	2
Aggregate funds available for financing	$800,000,000
Class A Notes [Member]
Subsequent Event [Line Items]
Maximum amount to be borrowed under financing agreement		160,000,000
Maturity Date		20-Jan-17
Class B Notes [Member]
Subsequent Event [Line Items]
Maximum amount to be borrowed under financing agreement		$40,000,000
Maturity Date		20-Jan-17
Cost of funds [Member] | Class A Notes [Member]
Subsequent Event [Line Items]
Basis interest rate		2.50%
Cost of funds [Member] | Class B Notes [Member]
Subsequent Event [Line Items]
Basis interest rate		5.00%