TerraForm Power NY (TERP) 10-Q 14 Aug 18 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2018	Jul. 31, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	TerraForm Power, Inc.
Entity Central Index Key	1,599,947
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
Amendment Flag	false
Entity Common Stock, Shares Outstanding		209,061,636

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operating revenues, net	$ 179,888	$ 170,367	$ 307,435	$ 321,502
Operating costs and expenses:
Cost of operations	49,805	32,205	87,128	66,543
Cost of operations - affiliate	0	3,427	0	9,025
General and administrative expenses	19,865	41,255	44,149	77,980
General and administrative expenses - affiliate	4,023	3,282	7,497	4,701
Acquisition-related costs	2,877	0	5,957	0
Acquisition-related costs - affiliate	6,025	0	6,630	0
Impairment of renewable energy facilities	0	1,429	15,240	1,429
Depreciation, accretion and amortization expense	69,994	63,222	135,584	124,209
Total operating costs and expenses	152,589	144,820	302,185	283,887
Operating income	27,299	25,547	5,250	37,615
Other expenses (income):
Interest expense (income), net	50,892	68,205	104,446	136,517
Gain on sale of renewable energy facilities	0	(37,116)	0	(37,116)
Gain on foreign currency exchange, net	(2,078)	(5,204)	(1,187)	(4,617)
Other expenses, net	1,663	1,773	2,512	2,133
Total other expenses, net	50,477	27,658	105,771	96,917
Loss before income tax expense (benefit)	(23,178)	(2,111)	(100,521)	(59,302)
Income tax expense (benefit)	4,434	(588)	3,404	(1,157)
Net loss	(27,612)	(1,523)	(103,925)	(58,145)
Less: Net income attributable to redeemable non-controlling interests	4,680	6,362	2,658	5,369
Less: Net loss attributable to non-controlling interests	(10,955)	(17,491)	(168,042)	(42,323)
Net (loss) income attributable to Class A common stockholders	$ (21,337)	$ 9,606	$ 61,459	$ (21,191)
(Loss) earnings per share:
Class A common stock - Basic and diluted ($ per share)		$ 0.08		$ (0.28)
Dividends declared per share:
Dividends declared per share ($ per share)	$ 0.19
Class A common stock
Weighted average number of shares:
Class A common stock - Basic (in shares)	161,568	92,257	154,890	92,165
Class A common stock - Diluted (in shares)	161,568	92,745	154,905	92,165
(Loss) earnings per share:
Class A common stock - Basic and diluted ($ per share)	$ (0.13)	$ 0.08	$ 0.40	$ (0.28)
Dividends declared per share:
Dividends declared per share ($ per share)	$ 0.19	$ 0	$ 0.38	$ 0

Unaudited Condensed Consolidat3

Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Statement of Comprehensive Income [Abstract]
Net loss		$ (27,612)	$ (1,523)	$ (103,925)	$ (58,145)
Foreign currency translation adjustments:
Net unrealized (loss) gain arising during the period		(5,392)	2,921	(8,675)	5,601
Reclassification of net realized loss (gain) into earnings	[1]	0	14,741	0	14,741
Hedging activities:
Net unrealized gain (loss) arising during the period		12,399	(3,432)	1,907	10,622
Reclassification of net realized loss (gain) into earnings		39	(235)	(923)	(621)
Other comprehensive income (loss), net of tax		7,046	13,995	(7,691)	30,343
Total comprehensive (loss) income		(20,566)	12,472	(111,616)	(27,802)
Less comprehensive income attributable to non-controlling interests:
Net income attributable to redeemable non-controlling interests		4,680	6,362	2,658	5,369
Net loss attributable to non-controlling interests		(10,955)	(17,491)	(168,042)	(42,323)
Foreign currency translation adjustments		0	(1,635)	0	(717)
Hedging activities		6	5,867	(1,237)	11,839
Comprehensive loss attributable to non-controlling interests		(6,269)	(6,897)	(166,621)	(25,832)
Comprehensive (loss) income attributable to Class A common stockholders		$ (14,297)	$ 19,369	$ 55,005	$ (1,970)
[1]	Represents reclassification of the accumulated foreign currency translation loss for substantially all of the Company’s portfolio of solar power plants located in the United Kingdom, as the Company’s sale of these facilities closed in the second quarter of 2017 as discussed in Note 4. Acquisitions and Dispositions. The pre-tax amount of $23.6 million was recognized within gain on sale of renewable energy facilities in the unaudited condensed consolidated statements of operations for the three and six months ended June 30, 2017.

Unaudited Condensed Consolidat4

Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Interest Expense | United Kingdom | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Reclassification of net realized loss (gain) into earnings, foreign currency translation adjustments, before tax	$ 23.6	$ 23.6

Unaudited Condensed Consolidat5

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 339,209	$ 128,087
Restricted cash	38,823	54,006
Accounts receivable, net	161,017	89,680
Prepaid expenses and other current assets	71,958	65,393
Due from affiliates	1,533	4,370
Total current assets	612,540	341,536
Renewable energy facilities, net, including consolidated variable interest entities of $3,196,816 and $3,273,848 in 2018 and 2017, respectively	6,634,926	4,801,925
Intangible assets, net, including consolidated variable interest entities of $797,844 and $823,629 in 2018 and 2017, respectively	2,033,854	1,077,786
Goodwill	114,780	0
Other assets	166,672	123,080
Restricted cash	138,053	42,694
Total assets	9,700,825	6,387,021
Current liabilities:
Current portion of long-term debt and financing lease obligations, including consolidated variable interest entities of $57,069 and $84,691 in 2018 and 2017, respectively	458,177	403,488
Accounts payable, accrued expenses and other current liabilities, including consolidated variable interest entities of $42,157 and $34,199 in 2018 and 2017, respectively	217,134	88,538
Deferred revenue	1,735	17,859
Due to affiliates	9,205	3,968
Total current liabilities	686,251	513,853
Long-term debt and financing lease obligations, less current portion, including consolidated variable interest entities of $923,565 and $833,388 in 2018 and 2017, respectively	5,416,939	3,195,312
Long-term debt - affiliate	86,000	0
Deferred revenue, less current portion	12,780	38,074
Deferred income taxes	202,767	24,972
Asset retirement obligations, including consolidated variable interest entities of $100,022 and $97,467 in 2018 and 2017, respectively	170,892	154,515
Other long-term liabilities	151,949	37,923
Total liabilities	6,727,578	3,964,649
Redeemable non-controlling interests	86,549	34,660
Stockholders' equity:
Class A common stock, $0.01 par value per share, 1,200,000,000 shares authorized, 209,562,056 and 148,586,447 shares issued in 2018 and 2017, respectively, and 209,061,636 and 148,086,027 shares outstanding in 2018 and 2017, respectively	2,096	1,486
Additional paid-in capital	2,468,771	1,872,125
Accumulated deficit	(301,167)	(387,204)
Accumulated other comprehensive income	37,400	48,018
Treasury stock, 500,420 shares in 2018 and 2017	(6,712)	(6,712)
Total TerraForm Power, Inc. stockholders' equity	2,200,388	1,527,713
Non-controlling interests	686,310	859,999
Total stockholders' equity	2,886,698	2,387,712
Total liabilities, redeemable non-controlling interests and stockholders' equity	$ 9,700,825	$ 6,387,021

Unaudited Condensed Consolidat6

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Noncurrent Assets:
Renewable energy facilities, net	$ 6,634,926	$ 4,801,925
Intangible assets, net	2,033,854	1,077,786
Current liabilities:
Current portion of long-term debt and financing lease obligations	458,177	403,488
Accounts payable, accrued expenses and other current liabilities	217,134	88,538
Noncurrent liabilities:
Long-term debt and financing lease obligations, less current portion	5,416,939	3,195,312
Asset retirement obligations	$ 170,892	$ 154,515
Stockholders' equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	1,200,000,000	1,200,000,000
Common stock, shares issued (in shares)	209,562,056	148,586,447
Common stock, shares outstanding (in shares)	209,061,636	148,086,027
Treasury stock (in shares)	500,420	500,420
Consolidated Variable Interest Entities
Noncurrent Assets:
Renewable energy facilities, net	$ 3,207,101	$ 3,273,848
Intangible assets, net	800,862	823,629
Current liabilities:
Current portion of long-term debt and financing lease obligations	62,006	84,691
Accounts payable, accrued expenses and other current liabilities	37,758	34,199
Noncurrent liabilities:
Long-term debt and financing lease obligations, less current portion	920,202	833,388
Asset retirement obligations	$ 100,022	$ 97,467

Unaudited Condensed Consolidat7

Unaudited Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands		Total	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Common Stock Held in Treasury	Total - Non-controlling Interests	Capital - Non-controlling Interests	Accumulated Deficit - Non-controlling Interests	Accumulated Other Comprehensive Loss - Non-controlling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment	[1]	$ 20,106	$ 20,414			$ 24,578	$ (4,164)		$ (308)		$ (308)
Common stock outstanding (in shares) at Dec. 31, 2017		148,086,027		148,586,000				(500,000)
Balance as of December 31, 2016 at Dec. 31, 2017		$ 2,387,712	1,527,713	$ 1,486	$ 1,872,125	(387,204)	48,018	$ (6,712)	859,999	$ 1,057,301	(198,196)	$ 894
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A common stock to affiliates (in shares)				60,976,000
Issuance of Class A common stock to affiliates		650,000	650,000	$ 610	649,390
Stock-based compensation		73	73		73
Net income (loss)		(106,583)	61,459			61,459			(168,042)		(168,042)
Dividends		(56,016)	(56,016)		(56,016)
Other comprehensive loss		(7,691)	(6,454)				(6,454)		(1,237)			(1,237)
Contributions from non-controlling interests in renewable energy facilities		7,685								7,685
Distributions to non-controlling interests in renewable energy facilities		(11,389)							(11,389)	(11,389)
Other		$ 2,801	3,199		3,199				(398)	102	(500)
Common stock outstanding (in shares) at Jun. 30, 2018		209,061,636		209,562,000				(500,000)
Balance as of June 30, 2017 at Jun. 30, 2018		$ 2,886,698	$ 2,200,388	$ 2,096	$ 2,468,771	$ (301,167)	$ 37,400	$ (6,712)	$ 686,310	$ 1,053,699	$ (367,046)	$ (343)
[1]	See Note 2. Summary of Significant Accounting Policies for discussion regarding the Company’s adoption of Accounting Standards Update (“ASU”) No. 2014-09, ASU No. 2016-08 and ASU No. 2017-12 as of January 1, 2018.

Unaudited Condensed Consolidat8

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net loss	$ (103,925)	$ (58,145)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, accretion and amortization expense	135,584	124,209
Amortization of favorable and unfavorable rate revenue contracts, net	19,567	19,524
Gain on sale of renewable energy facilities	0	(37,116)
Impairment of renewable energy facilities	15,240	1,429
Amortization of deferred financing costs and debt discounts	4,258	10,013
Unrealized (gain) loss on commodity contract derivatives, net	(8,777)	2,425
Unrealized (gain) loss on commodity contract derivatives, net	(5,292)	2,652
Recognition of deferred revenue	(929)	(6,069)
Stock-based compensation expense	73	5,200
Loss on extinguishment of debt, net	1,480	0
Loss on disposal of property, plant and equipment	6,764	0
Unrealized (gain) on foreign currency exchange, net	(5,684)	(4,336)
Deferred taxes	3,006	4,885
Other, net	344	4,922
Changes in assets and liabilities:
Accounts receivable	(6,389)	(30,436)
Prepaid expenses and other current assets	18,321	212
Accounts payable, accrued expenses and other current liabilities	(7,748)	11,442
Due to affiliates	2,308	0
Other, net	7,284	4,476
Net cash provided by operating activities	75,485	55,287
Cash flows from investing activities:
Capital expenditures	(10,333)	(5,068)
Proceeds from sale of renewable energy facilities, net of cash and restricted cash disposed	0	177,235
Proceeds from energy state rebate and reimbursable interconnection costs	6,006	22,188
Acquisition of renewable energy facilities from third parties, net of cash and restricted cash acquired	(831,484)	0
Acquisition of renewable energy facilities from third parties, net of cash and restricted cash acquired	(4,105)	0
Net cash (used in) provided by investing activities	(839,916)	194,355
Cash flows from financing activities:
Proceeds from issuance of Class A common stock to affiliates	650,000	0
Proceeds from Sponsor Line - affiliate	86,000	0
Revolving credit facility draws	539,053	0
Revolving credit facility repayments	(157,244)	(55,000)
Term Loan principal payments	(1,750)	0
Borrowings of non-recourse long-term debt	103,639	79,835
Principal payments and prepayments on non-recourse long-term debt	(102,257)	(141,613)
Debt financing fees	(3,652)	(3,735)
Contributions from non-controlling interests in renewable energy facilities	7,685	6,935
Distributions to non-controlling interests in renewable energy facilities	(12,507)	(17,125)
Due to/from affiliates, net	3,214	(3,311)
Net SunEdison investment	0	7,436
Payment of dividends	(56,016)	0
Recovery of related party short swing profit	2,994	0
Other financing activities	0	(133)
Net cash provided by (used in) financing activities	1,059,159	(126,711)
Net increase in cash, cash equivalents and restricted cash	294,728	122,931
Net change in cash, cash equivalents and restricted cash classified within assets held for sale	0	54,806
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(3,430)	2,336
Cash, cash equivalents and restricted cash at beginning of period	224,787	682,837
Cash, cash equivalents and restricted cash at end of period	516,085	862,910
Supplemental Disclosures:
Cash paid for interest	94,593	121,694
Cash paid for income taxes	$ 0	$ 0

Nature of Operations and Basis

Nature of Operations and Basis of Presentation	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Basis of Presentation	NATURE OF OPERATIONS AND BASIS OF PRESENTATION Nature of Operations On October 16, 2017, BRE TERP Holdings Inc., a wholly-owned subsidiary of Orion US Holdings 1 L.P. (“Orion Holdings”), merged with and into TerraForm Power, Inc. (“TerraForm Power”), with TerraForm Power continuing as the surviving corporation (the “Merger”). Prior to the consummation of the Merger, TerraForm Power and its subsidiaries (together, the “Company”) were controlled affiliates of SunEdison, Inc. (together with its consolidated subsidiaries excluding the Company and TerraForm Global, Inc. and its subsidiaries, “SunEdison”). As a result of the consummation of the Merger, a change of control of TerraForm Power occurred, and Orion Holdings, which is a controlled affiliate of Brookfield Asset Management Inc. (“Brookfield”), held 51% of the voting securities of TerraForm Power immediately following the Merger consummation. As a result of the Merger closing, TerraForm Power is no longer a controlled affiliate of SunEdison, Inc. and is now a controlled affiliate of Brookfield. As further discussed in Note 12. Stockholders’ Equity , on June 11, 2018, Orion Holdings and Brookfield BRP Holdings (Canada) Inc. (“BEP”), an Ontario Corporation and an affiliate of Brookfield, collectively purchased in a private placement a total of 60,975,609 shares of TerraForm Power’s Class A common stock for a price per share of $10.66 , representing total consideration of approximately $650.0 million . As a result of this private placement, affiliates of Brookfield held approximately 65% of TerraForm Power’s Class A common stock as of June 30, 2018. TerraForm Power is a holding company and its only material asset is an equity interest in TerraForm Power, LLC (“Terra LLC”), which through its subsidiaries owns and operates renewable energy facilities that have long-term contractual arrangements to sell the electricity generated by these facilities to third parties. The related green energy certificates, ancillary services and other environmental attributes generated by these facilities are also sold to third parties. TerraForm Power is the managing member of Terra LLC and operates, controls and consolidates the business affairs of Terra LLC. The Company is sponsored by Brookfield and has an objective to acquire operating solar and wind assets in North America and Western Europe. Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the results of wholly-owned and partially-owned subsidiaries in which the Company has a controlling interest with all significant intercompany accounts and transactions eliminated and have been prepared in accordance with the SEC regulations for interim financial information. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States of America (“U.S. GAAP”) for complete financial statements. The financial statements should be read in conjunction with the accounting policies and other disclosures as set forth in the notes to the Company’s annual financial statements for the year ended December 31, 2017, filed with the SEC on Form 10-K on March 7, 2018. Interim results are not necessarily indicative of results for a full year. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all material adjustments consisting of normal and recurring accruals necessary to present fairly the Company’s financial position as of June 30, 2018, results of operations and comprehensive (loss) income for the three and six months ended June 30, 2018 and 2017 and cash flows for the six months ended June 30, 2018 and 2017. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Use of Estimates In preparing the unaudited condensed consolidated financial statements, the Company used estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the financial statements. Such estimates also affect the reported amounts of revenues, expenses and cash flows during the reporting period. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations would be affected. Reconciliation of Cash and Cash Equivalents and Restricted Cash as Presented in the Unaudited Condensed Consolidated Statement of Cash Flows The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the unaudited condensed consolidated balance sheets to the total of the same such amounts shown in the unaudited condensed consolidated statement of cash flows for the six months ended June 30, 2018. (In thousands) June 30, December 31, Cash and cash equivalents $ 339,209 $ 128,087 Restricted cash - current 38,823 54,006 Restricted cash - non-current 138,053 42,694 Cash, cash equivalents and restricted cash shown in the unaudited condensed consolidated statement of cash flows $ 516,085 $ 224,787 Restricted cash consists of cash on deposit in financial institutions that is restricted to satisfy the requirements of certain debt agreements and funds held within the Company's project companies that are restricted for current debt service payments and other purposes in accordance with the applicable debt agreements. These restrictions include: (i) cash on deposit in collateral accounts, debt service reserve accounts and maintenance reserve accounts; and (ii) cash on deposit in operating accounts but subject to distribution restrictions related to debt defaults existing as of the balance sheet date. As discussed in Note 8 . Long-term Debt , the Company was in default under certain of its non-recourse financing agreements as of the financial statement issuance date for the six months ended June 30, 2018 and for the year ended December 31, 2017. As a result, the Company reclassified $15.5 million and $18.8 million of non-current restricted cash to current as of June 30, 2018 and December 31, 2017, respectively, consistent with the corresponding debt classification, as the restrictions that required the cash balances to be classified as non-current restricted cash were driven by the financing agreements. As of June 30, 2018 and December 31, 2017, $8.0 million and $21.7 million , respectively, of cash and cash equivalents was also reclassified to current restricted cash as the cash balances were subject to distribution restrictions related to debt defaults that existed as of the respective balance sheet date. Non-controlling Interests - Impact of the Tax Cuts and Jobs Act Enactment On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”), which enacted major changes to the U.S. tax code, including a reduction in the U.S. federal corporate income tax rate from 35% to 21% , effective January 1, 2018. Since the 21% rate enacted in December 2017 went into effect on January 1, 2018, the hypothetical liquidation at book value (“HLBV”) methodology utilized by the Company to determine the value of its non-controlling interests began to use the new rate on that date. The HLBV method is a point in time estimate that utilizes inputs and assumptions in effect at each balance sheet date based on the liquidation provisions of the respective operating partnership agreements. For the six months ended June 30, 2018, $151.2 million of the decline in the non-controlling interests balance and a corresponding allocation of net loss attributable to non-controlling interests was driven by this reduction in the tax rate used in the HLBV methodology used by the Company. In the calculation of the carrying values through HLBV, the Company allocated significantly lower amounts to certain non-controlling interests (i.e., tax equity investors) in order to achieve their contracted after-tax rate of return as a result of the reduction of the federal income tax rate from 35% to 21% as specified in the Tax Act. Restructuring In connection with the consummation of the Merger and the relocation of the headquarters of the Company to New York, New York, the Company announced a restructuring plan that went into effect upon the closing of the Merger, which was substantially completed early in the third quarter of 2018. The Company recognized $1.0 million and $2.3 million of additional severance and transition bonus costs during the three and six months ended June 30, 2018, respectively, within general and administrative expenses in the unaudited condensed consolidated statements of operations. The Company made $1.4 million and $2.2 million of payments related to this restructuring during the three and six months ended June 30, 2018, respectively. The balance of the accrued severance and transition bonuses was $2.8 million as of June 30, 2018. Recently Adopted Accounting Standards - Guidance Adopted in 2018 In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) , which replaces most existing revenue recognition guidance in U.S. GAAP and requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. Additionally, the new standard requires an entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606), Principal versus Agent Considerations (Reporting Revenue Gross versus Net) , which clarifies how to apply the implementation guidance on principal versus agent considerations related to the sale of goods or services to a customer as updated by ASU No. 2014-09. The Company adopted these standards as of January 1, 2018, which it collectively refers to as “Topic 606.” The Company analyzed the impact of Topic 606 on its revenue contracts which primarily include bundled energy and incentive sales through power purchase agreements (“PPAs”), individual renewable energy certificate (“REC”) sales, and upfront sales of federal & state incentive benefits recorded as deferred revenue and accreted into revenue. The Company elected to apply a modified retrospective approach with a cumulative-effect adjustment to accumulated deficit recognized as of January 1, 2018 for changes to revenue recognition resulting from Topic 606 adoption as described below. The Company adopted Topic 606 for all revenue contracts in-scope that had future performance obligations at January 1, 2018, and elected to use the contract modification practical expedient for purposes of computing the cumulative transition adjustment. See Note 3. Revenue for additional disclosures required by the new guidance. The Company accounts for the majority of its PPAs as operating leases under Accounting Standards Codification (“ASC”) 840, Leases and recognizes rental income as revenue when the electricity is delivered. The Company elected not to early adopt ASC 842, Leases in fiscal 2018 and therefore these PPAs are currently being evaluated in anticipation of the new lease standard adoption in fiscal 2019. For PPAs under the scope of Topic 606 in fiscal 2018, the Company concluded that there were no material changes to revenue recognition patterns from existing accounting practice. See Note 3. Revenue for the new revenue recognition policy. The Company evaluated the impact of Topic 606 as it relates to the individual sale of RECs. In certain jurisdictions, there may be a lag between physical generation of the underlying energy and the transfer of RECs to the customer due to administrative processes imposed by state regulations. Under the Company’s previous accounting policy, revenue was recognized as the underlying electricity was generated if the sale had been contracted with the customer. Based on the framework in Topic 606, for a portion of the existing individual REC sale arrangements where the transfer of control to the customer is determined to occur upon the transfer of the RECs, the Company now recognizes revenue commensurate with the transfer of RECs to the customer as compared to the generation of the underlying energy under the previous accounting policy. Revenue recognition practices for the remainder of existing individual REC sale arrangements remain the same; that is, revenue is recognized based on the underlying generation of energy because the contracted RECs are produced from a designated facility and control of the RECs transfers to the customer upon generation of the underlying energy. The adoption of Topic 606, as it relates to the individual sale of RECs, resulted in an increase in accumulated deficit on January 1, 2018 of $20.5 million , net of tax, and net of $0.3 million and $4.5 million that was allocated to non-controlling interests and redeemable non-controlling interests, respectively. The adjustments for accumulated deficit and non-controlling interests are reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018 and the redeemable non-controlling interests adjustment is reflected within cumulative-effect adjustment in the redeemable non-controlling interests roll-forward presented above. The impact on the Company’s results of operations for the first half of 2018 was minimal and is expected to be minimal for the remainder of 2018. The Company evaluated the impact of Topic 606 as it relates to the upfront sale of investment tax credits (“ITCs”) through its lease pass-through fund arrangements. The amounts allocated to the ITCs were initially recorded as deferred revenue in the consolidated balance sheet, and subsequently, one-fifth of the amounts allocated to the ITCs was recognized annually as incentives revenue in the consolidated statement of operations based on the anniversary of each solar energy system’s placed-in-service date. The Company concluded that revenue related to the sale of ITCs through its lease pass-through arrangements should be recognized at the point in time when the related solar energy systems are placed in service. Previously, the Company recognized this revenue evenly over the five -year ITC recapture period. The Company concluded that the likelihood of a recapture event related to these assessments is remote. The adoption of Topic 606, as it relates to the upfront sale of ITCs, resulted in a decrease in accumulated deficit on January 1, 2018 of $40.9 million , net of tax, which is reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018. The impact on the Company’s results of operations for the three and six months ended June 30, 2018 resulted in a decrease in non-cash deferred revenue recognition of $1.6 million and $5.1 million , respectively, and is expected to result in a decrease in non-cash deferred revenue recognition of approximately $11.2 million for the remaining six months of 2018. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230), Classification of Certain Cash Receipts and Cash Payments . The amendments of ASU No. 2016-15 were issued to address eight specific cash flow issues for which stakeholders have indicated to the FASB that a diversity in practice existed in how entities were presenting and classifying these items in the statement of cash flows. The issues addressed by ASU No. 2016-15 include but are not limited to the classification of debt prepayment and debt extinguishment costs, payments made for contingent consideration for a business combination, proceeds from the settlement of insurance proceeds, distributions received from equity method investees and separately identifiable cash flows and the application of the predominance principle. The adoption of ASU No. 2016-15 is required to be applied retrospectively. The Company adopted ASU No. 2016-15 as of January 1, 2018, which did not result in any material adjustments to the Company’s consolidated statements of cash flows. In October 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740), Intra-Entity Transfers of Assets Other Than Inventory . The amendments of ASU No. 2016-16 were issued to improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. Previous GAAP prohibited the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset had been sold to an outside party which resulted in diversity in practice and increased complexity within financial reporting. The amendments of ASU No. 2016-16 require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs and do not require new disclosure requirements. The adoption of ASU No. 2016-16 should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The adoption of ASU No. 2016-16 as of January 1, 2018 did not have an impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business . The amendment seeks to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The amendments should be applied prospectively on or after the effective dates. Accordingly, the Company’s adoption of ASU No. 2017-01 as of January 1, 2018 did not have an impact on the Company’s historical financial statements. Based on the Company’s evaluation of the new guidance, the Company determined that the acquisition of the tendered shares of Saeta on June 12, 2018 qualifies to be accounted for as an acquisition of a business and the Company’s acquisition of a 6 megawatt (“MW”) portfolio of operating solar distributed generation assets located in California and New Jersey on June 29, 2018 should be accounted for as an acquisition of assets. See Note 4. Acquisitions and Dispositions for further discussion of the Saeta acquisition. In February 2017, the FASB issued ASU No. 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets . This ASU is meant to clarify the scope of ASC Subtopic 610-20, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets and to add guidance for partial sales of nonfinancial assets. ASU No. 2017-05 is to be applied using a full retrospective method or a modified retrospective method as outlined in the guidance. The adoption of ASU No. 2017-05 as of January 1, 2018 did not have an impact on the Company’s consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting . The amendment clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as a modification. The new guidance is expected to reduce diversity in practice and result in fewer changes to the terms of an award being accounted for as a modification. Changes to the terms or conditions of a share-based payment award that do not impact the fair value of the award, vesting conditions and the classification as an equity or liability instrument will not need to be assessed under modification accounting. The amendments in this update should be applied prospectively to an award modified on or after the adoption date. Accordingly, the Company’s adoption of ASU No. 2017-09 as of January 1, 2018 did not have an impact on the Company’s historical financial statements. The Company did not change the terms or conditions of any unvested share-based payment awards outstanding during the six months ended June 30, 2018 but will apply the impact of this standard in the future should it change the terms or conditions of any share-based payment awards. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities . This ASU amends the hedge accounting model to enable entities to better portray the economics of their risk management activities in the financial statements and simplifies the application of hedge accounting in certain situations. ASU No. 2017-12 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018, with early adoption permitted. ASU 2017-12 requires a modified retrospective transition method in which the Company recognizes the cumulative effect of the change on the opening balance of each affected component of equity as of the date of adoption. The Company adopted ASU 2017-12 on March 26, 2018 with the adoption impact reflected on a modified retrospective basis as of January 1, 2018, which resulted in the following primary changes: • The ineffective hedging portion of derivatives designated as hedging instruments is no longer required to be measured, recognized or reported. Alternatively, the entire change in the fair value of the designated hedging instrument is recorded in accumulated other comprehensive income (“AOCI”); • The Company will perform ongoing prospective and retrospective hedge effectiveness assessments qualitatively after performing the initial test of hedge effectiveness on a quantitative basis and only to the extent that an expectation of high effectiveness can be supported on a qualitative basis in subsequent periods; • For derivatives with periodic cash settlements and a non-zero fair value at hedge inception, the gains or losses recorded in AOCI in a qualifying cash flow hedging relationship are reclassified to earnings on a systematic and rational basis over the hedge term; and • For derivatives with components excluded from the assessment of hedge effectiveness, the gains or losses recorded in AOCI on such excluded components in a qualifying cash flow hedging relationship are reclassified to earnings on a systematic and rational basis over the hedge term. The adoption of ASU 2017-12 resulted in a cumulative-effect adjustment of $4.2 million , net of tax of $1.6 million , representing a decrease in accumulated deficit and AOCI, which is reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018. In March 2018, the FASB issued ASU No. 2018-05, Income Taxes (Topic 740) – Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 . The ASU added seven paragraphs to ASC 740, Income Taxes , that contain SEC guidance related to the application of U.S. GAAP when preparing an initial accounting of the income tax effects of the Tax Act which, among other things, allows for a measurement period not to exceed one year for companies to finalize the provisional amounts recorded as of December 31, 2017. The ASU was effective upon issuance. See Note 9. Income Taxes for disclosures on the Company’s accounting for the Tax Act. Recently Issued Accounting Standards Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) , and in July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases, which primarily change the lessee’s accounting for operating leases by requiring recognition of lease right-of-use assets and lease liabilities. The Company expects to adopt the guidance on January 1, 2019. The issued guidance requires a modified retrospective transition approach, which requires entities to recognize and measure leases at the beginning of the earliest period presented. In January 2018, the FASB proposed amending the standard to give entities another option for transition. The proposed transition method would allow entities to initially apply the requirements of the standard in the period of adoption (January 1, 2019). The Company will assess this transition option if the FASB issues the revised standard. The Company expects to elect certain of the practical expedients permitted in the issued standard, including the expedient that permits the Company to retain its existing lease assessment and classification. In January 2018, the FASB issued additional guidance which provides another optional transition practical expedient that allows entities to not evaluate existing and expired land easements under the new guidance at adoption if they were not previously accounted for as leases. The Company is currently working through an adoption plan which includes the evaluation of lease contracts compared to the new standard. While the Company is currently evaluating the impact the new guidance will have on its financial position and results of operations, the Company expects to recognize lease liabilities and right of use assets. The extent of the increase to assets and liabilities associated with these amounts remains to be determined pending the Company’s review of its existing lease contracts which may contain embedded leases. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment . The amendment simplifies the accounting for goodwill impairment by removing Step 2 of the current test, which requires calculation of a hypothetical purchase price allocation. Under the revised guidance, goodwill impairment will be measured as the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill (currently Step 1 of the two-step impairment test). Entities will continue to have the option to perform a qualitative assessment to determine if a quantitative impairment test is necessary. The standard is effective January 1, 2020, with early adoption permitted, and must be adopted on a prospective basis. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income to help entities address certain stranded income tax effects in AOCI resulting from the U.S. government’s enactment of the Tax Act on December 22, 2017. The amendment provides entities with an option to reclassify stranded tax effects within AOCI to retained earnings in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act (or portion thereof) is recorded. The amendment also includes disclosure requirements regarding the issuer’s accounting policy for releasing income tax effects from AOCI. The optional guidance is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted, and entities should apply the provisions of the amendment either in the period of adoption or retrospectively to each period (or periods) in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act is recognized. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-03, Technical Corrections and Improvements to Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities . This ASU amends and supersedes various paragraphs that contain SEC guidance in ASC 320, Investments - Debt Securities and ASC 980, Regulated Operations . ASU No. 2018-03 is effective for public business entities for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years beginning after June 15, 2018. Public business entities with fiscal years beginning between December 15, 2017 and June 15, 2018 are not required to adopt these amendments until the interim period beginning after June 15, 2018. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NATURE OF OPERATIONS AND BASIS OF PRESENTATION Nature of Operations On October 16, 2017, BRE TERP Holdings Inc., a wholly-owned subsidiary of Orion US Holdings 1 L.P. (“Orion Holdings”), merged with and into TerraForm Power, Inc. (“TerraForm Power”), with TerraForm Power continuing as the surviving corporation (the “Merger”). Prior to the consummation of the Merger, TerraForm Power and its subsidiaries (together, the “Company”) were controlled affiliates of SunEdison, Inc. (together with its consolidated subsidiaries excluding the Company and TerraForm Global, Inc. and its subsidiaries, “SunEdison”). As a result of the consummation of the Merger, a change of control of TerraForm Power occurred, and Orion Holdings, which is a controlled affiliate of Brookfield Asset Management Inc. (“Brookfield”), held 51% of the voting securities of TerraForm Power immediately following the Merger consummation. As a result of the Merger closing, TerraForm Power is no longer a controlled affiliate of SunEdison, Inc. and is now a controlled affiliate of Brookfield. As further discussed in Note 12. Stockholders’ Equity , on June 11, 2018, Orion Holdings and Brookfield BRP Holdings (Canada) Inc. (“BEP”), an Ontario Corporation and an affiliate of Brookfield, collectively purchased in a private placement a total of 60,975,609 shares of TerraForm Power’s Class A common stock for a price per share of $10.66 , representing total consideration of approximately $650.0 million . As a result of this private placement, affiliates of Brookfield held approximately 65% of TerraForm Power’s Class A common stock as of June 30, 2018. TerraForm Power is a holding company and its only material asset is an equity interest in TerraForm Power, LLC (“Terra LLC”), which through its subsidiaries owns and operates renewable energy facilities that have long-term contractual arrangements to sell the electricity generated by these facilities to third parties. The related green energy certificates, ancillary services and other environmental attributes generated by these facilities are also sold to third parties. TerraForm Power is the managing member of Terra LLC and operates, controls and consolidates the business affairs of Terra LLC. The Company is sponsored by Brookfield and has an objective to acquire operating solar and wind assets in North America and Western Europe. Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the results of wholly-owned and partially-owned subsidiaries in which the Company has a controlling interest with all significant intercompany accounts and transactions eliminated and have been prepared in accordance with the SEC regulations for interim financial information. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States of America (“U.S. GAAP”) for complete financial statements. The financial statements should be read in conjunction with the accounting policies and other disclosures as set forth in the notes to the Company’s annual financial statements for the year ended December 31, 2017, filed with the SEC on Form 10-K on March 7, 2018. Interim results are not necessarily indicative of results for a full year. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all material adjustments consisting of normal and recurring accruals necessary to present fairly the Company’s financial position as of June 30, 2018, results of operations and comprehensive (loss) income for the three and six months ended June 30, 2018 and 2017 and cash flows for the six months ended June 30, 2018 and 2017. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Use of Estimates In preparing the unaudited condensed consolidated financial statements, the Company used estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the financial statements. Such estimates also affect the reported amounts of revenues, expenses and cash flows during the reporting period. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations would be affected. Reconciliation of Cash and Cash Equivalents and Restricted Cash as Presented in the Unaudited Condensed Consolidated Statement of Cash Flows The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the unaudited condensed consolidated balance sheets to the total of the same such amounts shown in the unaudited condensed consolidated statement of cash flows for the six months ended June 30, 2018. (In thousands) June 30, December 31, Cash and cash equivalents $ 339,209 $ 128,087 Restricted cash - current 38,823 54,006 Restricted cash - non-current 138,053 42,694 Cash, cash equivalents and restricted cash shown in the unaudited condensed consolidated statement of cash flows $ 516,085 $ 224,787 Restricted cash consists of cash on deposit in financial institutions that is restricted to satisfy the requirements of certain debt agreements and funds held within the Company's project companies that are restricted for current debt service payments and other purposes in accordance with the applicable debt agreements. These restrictions include: (i) cash on deposit in collateral accounts, debt service reserve accounts and maintenance reserve accounts; and (ii) cash on deposit in operating accounts but subject to distribution restrictions related to debt defaults existing as of the balance sheet date. As discussed in Note 8 . Long-term Debt , the Company was in default under certain of its non-recourse financing agreements as of the financial statement issuance date for the six months ended June 30, 2018 and for the year ended December 31, 2017. As a result, the Company reclassified $15.5 million and $18.8 million of non-current restricted cash to current as of June 30, 2018 and December 31, 2017, respectively, consistent with the corresponding debt classification, as the restrictions that required the cash balances to be classified as non-current restricted cash were driven by the financing agreements. As of June 30, 2018 and December 31, 2017, $8.0 million and $21.7 million , respectively, of cash and cash equivalents was also reclassified to current restricted cash as the cash balances were subject to distribution restrictions related to debt defaults that existed as of the respective balance sheet date. Non-controlling Interests - Impact of the Tax Cuts and Jobs Act Enactment On December 22, 2017, the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the “Tax Act”), which enacted major changes to the U.S. tax code, including a reduction in the U.S. federal corporate income tax rate from 35% to 21% , effective January 1, 2018. Since the 21% rate enacted in December 2017 went into effect on January 1, 2018, the hypothetical liquidation at book value (“HLBV”) methodology utilized by the Company to determine the value of its non-controlling interests began to use the new rate on that date. The HLBV method is a point in time estimate that utilizes inputs and assumptions in effect at each balance sheet date based on the liquidation provisions of the respective operating partnership agreements. For the six months ended June 30, 2018, $151.2 million of the decline in the non-controlling interests balance and a corresponding allocation of net loss attributable to non-controlling interests was driven by this reduction in the tax rate used in the HLBV methodology used by the Company. In the calculation of the carrying values through HLBV, the Company allocated significantly lower amounts to certain non-controlling interests (i.e., tax equity investors) in order to achieve their contracted after-tax rate of return as a result of the reduction of the federal income tax rate from 35% to 21% as specified in the Tax Act. Restructuring In connection with the consummation of the Merger and the relocation of the headquarters of the Company to New York, New York, the Company announced a restructuring plan that went into effect upon the closing of the Merger, which was substantially completed early in the third quarter of 2018. The Company recognized $1.0 million and $2.3 million of additional severance and transition bonus costs during the three and six months ended June 30, 2018, respectively, within general and administrative expenses in the unaudited condensed consolidated statements of operations. The Company made $1.4 million and $2.2 million of payments related to this restructuring during the three and six months ended June 30, 2018, respectively. The balance of the accrued severance and transition bonuses was $2.8 million as of June 30, 2018. Recently Adopted Accounting Standards - Guidance Adopted in 2018 In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) , which replaces most existing revenue recognition guidance in U.S. GAAP and requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. Additionally, the new standard requires an entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606), Principal versus Agent Considerations (Reporting Revenue Gross versus Net) , which clarifies how to apply the implementation guidance on principal versus agent considerations related to the sale of goods or services to a customer as updated by ASU No. 2014-09. The Company adopted these standards as of January 1, 2018, which it collectively refers to as “Topic 606.” The Company analyzed the impact of Topic 606 on its revenue contracts which primarily include bundled energy and incentive sales through power purchase agreements (“PPAs”), individual renewable energy certificate (“REC”) sales, and upfront sales of federal & state incentive benefits recorded as deferred revenue and accreted into revenue. The Company elected to apply a modified retrospective approach with a cumulative-effect adjustment to accumulated deficit recognized as of January 1, 2018 for changes to revenue recognition resulting from Topic 606 adoption as described below. The Company adopted Topic 606 for all revenue contracts in-scope that had future performance obligations at January 1, 2018, and elected to use the contract modification practical expedient for purposes of computing the cumulative transition adjustment. See Note 3. Revenue for additional disclosures required by the new guidance. The Company accounts for the majority of its PPAs as operating leases under Accounting Standards Codification (“ASC”) 840, Leases and recognizes rental income as revenue when the electricity is delivered. The Company elected not to early adopt ASC 842, Leases in fiscal 2018 and therefore these PPAs are currently being evaluated in anticipation of the new lease standard adoption in fiscal 2019. For PPAs under the scope of Topic 606 in fiscal 2018, the Company concluded that there were no material changes to revenue recognition patterns from existing accounting practice. See Note 3. Revenue for the new revenue recognition policy. The Company evaluated the impact of Topic 606 as it relates to the individual sale of RECs. In certain jurisdictions, there may be a lag between physical generation of the underlying energy and the transfer of RECs to the customer due to administrative processes imposed by state regulations. Under the Company’s previous accounting policy, revenue was recognized as the underlying electricity was generated if the sale had been contracted with the customer. Based on the framework in Topic 606, for a portion of the existing individual REC sale arrangements where the transfer of control to the customer is determined to occur upon the transfer of the RECs, the Company now recognizes revenue commensurate with the transfer of RECs to the customer as compared to the generation of the underlying energy under the previous accounting policy. Revenue recognition practices for the remainder of existing individual REC sale arrangements remain the same; that is, revenue is recognized based on the underlying generation of energy because the contracted RECs are produced from a designated facility and control of the RECs transfers to the customer upon generation of the underlying energy. The adoption of Topic 606, as it relates to the individual sale of RECs, resulted in an increase in accumulated deficit on January 1, 2018 of $20.5 million , net of tax, and net of $0.3 million and $4.5 million that was allocated to non-controlling interests and redeemable non-controlling interests, respectively. The adjustments for accumulated deficit and non-controlling interests are reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018 and the redeemable non-controlling interests adjustment is reflected within cumulative-effect adjustment in the redeemable non-controlling interests roll-forward presented above. The impact on the Company’s results of operations for the first half of 2018 was minimal and is expected to be minimal for the remainder of 2018. The Company evaluated the impact of Topic 606 as it relates to the upfront sale of investment tax credits (“ITCs”) through its lease pass-through fund arrangements. The amounts allocated to the ITCs were initially recorded as deferred revenue in the consolidated balance sheet, and subsequently, one-fifth of the amounts allocated to the ITCs was recognized annually as incentives revenue in the consolidated statement of operations based on the anniversary of each solar energy system’s placed-in-service date. The Company concluded that revenue related to the sale of ITCs through its lease pass-through arrangements should be recognized at the point in time when the related solar energy systems are placed in service. Previously, the Company recognized this revenue evenly over the five -year ITC recapture period. The Company concluded that the likelihood of a recapture event related to these assessments is remote. The adoption of Topic 606, as it relates to the upfront sale of ITCs, resulted in a decrease in accumulated deficit on January 1, 2018 of $40.9 million , net of tax, which is reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018. The impact on the Company’s results of operations for the three and six months ended June 30, 2018 resulted in a decrease in non-cash deferred revenue recognition of $1.6 million and $5.1 million , respectively, and is expected to result in a decrease in non-cash deferred revenue recognition of approximately $11.2 million for the remaining six months of 2018. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230), Classification of Certain Cash Receipts and Cash Payments . The amendments of ASU No. 2016-15 were issued to address eight specific cash flow issues for which stakeholders have indicated to the FASB that a diversity in practice existed in how entities were presenting and classifying these items in the statement of cash flows. The issues addressed by ASU No. 2016-15 include but are not limited to the classification of debt prepayment and debt extinguishment costs, payments made for contingent consideration for a business combination, proceeds from the settlement of insurance proceeds, distributions received from equity method investees and separately identifiable cash flows and the application of the predominance principle. The adoption of ASU No. 2016-15 is required to be applied retrospectively. The Company adopted ASU No. 2016-15 as of January 1, 2018, which did not result in any material adjustments to the Company’s consolidated statements of cash flows. In October 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740), Intra-Entity Transfers of Assets Other Than Inventory . The amendments of ASU No. 2016-16 were issued to improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. Previous GAAP prohibited the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset had been sold to an outside party which resulted in diversity in practice and increased complexity within financial reporting. The amendments of ASU No. 2016-16 require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs and do not require new disclosure requirements. The adoption of ASU No. 2016-16 should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The adoption of ASU No. 2016-16 as of January 1, 2018 did not have an impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business . The amendment seeks to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The amendments should be applied prospectively on or after the effective dates. Accordingly, the Company’s adoption of ASU No. 2017-01 as of January 1, 2018 did not have an impact on the Company’s historical financial statements. Based on the Company’s evaluation of the new guidance, the Company determined that the acquisition of the tendered shares of Saeta on June 12, 2018 qualifies to be accounted for as an acquisition of a business and the Company’s acquisition of a 6 megawatt (“MW”) portfolio of operating solar distributed generation assets located in California and New Jersey on June 29, 2018 should be accounted for as an acquisition of assets. See Note 4. Acquisitions and Dispositions for further discussion of the Saeta acquisition. In February 2017, the FASB issued ASU No. 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets . This ASU is meant to clarify the scope of ASC Subtopic 610-20, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets and to add guidance for partial sales of nonfinancial assets. ASU No. 2017-05 is to be applied using a full retrospective method or a modified retrospective method as outlined in the guidance. The adoption of ASU No. 2017-05 as of January 1, 2018 did not have an impact on the Company’s consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting . The amendment clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as a modification. The new guidance is expected to reduce diversity in practice and result in fewer changes to the terms of an award being accounted for as a modification. Changes to the terms or conditions of a share-based payment award that do not impact the fair value of the award, vesting conditions and the classification as an equity or liability instrument will not need to be assessed under modification accounting. The amendments in this update should be applied prospectively to an award modified on or after the adoption date. Accordingly, the Company’s adoption of ASU No. 2017-09 as of January 1, 2018 did not have an impact on the Company’s historical financial statements. The Company did not change the terms or conditions of any unvested share-based payment awards outstanding during the six months ended June 30, 2018 but will apply the impact of this standard in the future should it change the terms or conditions of any share-based payment awards. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities . This ASU amends the hedge accounting model to enable entities to better portray the economics of their risk management activities in the financial statements and simplifies the application of hedge accounting in certain situations. ASU No. 2017-12 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018, with early adoption permitted. ASU 2017-12 requires a modified retrospective transition method in which the Company recognizes the cumulative effect of the change on the opening balance of each affected component of equity as of the date of adoption. The Company adopted ASU 2017-12 on March 26, 2018 with the adoption impact reflected on a modified retrospective basis as of January 1, 2018, which resulted in the following primary changes: • The ineffective hedging portion of derivatives designated as hedging instruments is no longer required to be measured, recognized or reported. Alternatively, the entire change in the fair value of the designated hedging instrument is recorded in accumulated other comprehensive income (“AOCI”); • The Company will perform ongoing prospective and retrospective hedge effectiveness assessments qualitatively after performing the initial test of hedge effectiveness on a quantitative basis and only to the extent that an expectation of high effectiveness can be supported on a qualitative basis in subsequent periods; • For derivatives with periodic cash settlements and a non-zero fair value at hedge inception, the gains or losses recorded in AOCI in a qualifying cash flow hedging relationship are reclassified to earnings on a systematic and rational basis over the hedge term; and • For derivatives with components excluded from the assessment of hedge effectiveness, the gains or losses recorded in AOCI on such excluded components in a qualifying cash flow hedging relationship are reclassified to earnings on a systematic and rational basis over the hedge term. The adoption of ASU 2017-12 resulted in a cumulative-effect adjustment of $4.2 million , net of tax of $1.6 million , representing a decrease in accumulated deficit and AOCI, which is reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018. In March 2018, the FASB issued ASU No. 2018-05, Income Taxes (Topic 740) – Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 . The ASU added seven paragraphs to ASC 740, Income Taxes , that contain SEC guidance related to the application of U.S. GAAP when preparing an initial accounting of the income tax effects of the Tax Act which, among other things, allows for a measurement period not to exceed one year for companies to finalize the provisional amounts recorded as of December 31, 2017. The ASU was effective upon issuance. See Note 9. Income Taxes for disclosures on the Company’s accounting for the Tax Act. Recently Issued Accounting Standards Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) , and in July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases, which primarily change the lessee’s accounting for operating leases by requiring recognition of lease right-of-use assets and lease liabilities. The Company expects to adopt the guidance on January 1, 2019. The issued guidance requires a modified retrospective transition approach, which requires entities to recognize and measure leases at the beginning of the earliest period presented. In January 2018, the FASB proposed amending the standard to give entities another option for transition. The proposed transition method would allow entities to initially apply the requirements of the standard in the period of adoption (January 1, 2019). The Company will assess this transition option if the FASB issues the revised standard. The Company expects to elect certain of the practical expedients permitted in the issued standard, including the expedient that permits the Company to retain its existing lease assessment and classification. In January 2018, the FASB issued additional guidance which provides another optional transition practical expedient that allows entities to not evaluate existing and expired land easements under the new guidance at adoption if they were not previously accounted for as leases. The Company is currently working through an adoption plan which includes the evaluation of lease contracts compared to the new standard. While the Company is currently evaluating the impact the new guidance will have on its financial position and results of operations, the Company expects to recognize lease liabilities and right of use assets. The extent of the increase to assets and liabilities associated with these amounts remains to be determined pending the Company’s review of its existing lease contracts which may contain embedded leases. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment . The amendment simplifies the accounting for goodwill impairment by removing Step 2 of the current test, which requires calculation of a hypothetical purchase price allocation. Under the revised guidance, goodwill impairment will be measured as the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill (currently Step 1 of the two-step impairment test). Entities will continue to have the option to perform a qualitative assessment to determine if a quantitative impairment test is necessary. The standard is effective January 1, 2020, with early adoption permitted, and must be adopted on a prospective basis. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income to help entities address certain stranded income tax effects in AOCI resulting from the U.S. government’s enactment of the Tax Act on December 22, 2017. The amendment provides entities with an option to reclassify stranded tax effects within AOCI to retained earnings in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act (or portion thereof) is recorded. The amendment also includes disclosure requirements regarding the issuer’s accounting policy for releasing income tax effects from AOCI. The optional guidance is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted, and entities should apply the provisions of the amendment either in the period of adoption or retrospectively to each period (or periods) in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act is recognized. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-03, Technical Corrections and Improvements to Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities . This ASU amends and supersedes various paragraphs that contain SEC guidance in ASC 320, Investments - Debt Securities and ASC 980, Regulated Operations . ASU No. 2018-03 is effective for public business entities for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years beginning after June 15, 2018. Public business entities with fiscal years beginning between December 15, 2017 and June 15, 2018 are not required to adopt these amendments until the interim period beginning after June 15, 2018. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE As discussed in Note 2. Summary of Significant Accounting Policies , on January 1, 2018, the Company adopted Topic 606. The following tables present revenue disaggregated by segment and major product for the three and six months ended June 30, 2018 and provide a reconciliation of the adoption impact of Topic 606 on the unaudited condensed consolidated statements of operations for the three and six months ended June 30, 2018 and unaudited condensed consolidated balance sheet as of June 30, 2018. There was no net impact on net cash provided by operating activities in the unaudited condensed consolidated statement of cash flows for the six months ended June 30, 2018 resulting from the adoption of Topic 606. Topic 606 Adoption Impact on Unaudited Condensed Consolidated Statements of Operations Three Months Ended June 30, 2018 As Reported Adjustments Amounts excluding Topic 606 Adoption (In thousands) Solar Wind Regulated Wind and Solar Total REC Sales ITC Sales PPA rental income $ 55,366 $ 50,899 — $ 106,265 $ — $ — $ 106,265 Commodity derivatives — 21,441 — 21,441 — — 21,441 PPA revenue 13,458 6,359 — 19,817 — — 19,817 Regulated solar and wind revenue — — 21,286 21,286 — — 21,286 Amortization of favorable and unfavorable rate revenue contracts, net (1,966 ) (7,784 ) — (9,750 ) — — (9,750 ) Energy revenue 66,858 70,915 21,286 159,059 — — 159,059 Incentive revenue 16,463 4,366 — 20,829 5,586 1,598 28,013 Operating revenues, net 83,321 75,281 21,286 179,888 5,586 1,598 187,072 Operating costs and expenses 152,589 — — 152,589 Operating income 27,299 5,586 1,598 34,483 Other expenses, net 50,477 — — 50,477 (Loss) income before income tax expense (23,178 ) 5,586 1,598 (15,994 ) Income tax expense 4,434 — — 4,434 Net loss $ (27,612 ) $ 5,586 $ 1,598 $ (20,428 ) Six Months Ended June 30, 2018 As Reported Adjustments Amounts excluding Topic 606 Adoption (In thousands) Solar Wind Regulated Wind and Solar Total REC Sales ITC Sales PPA rental income $ 92,134 $ 103,312 $ — $ 195,446 $ — $ — $ 195,446 Commodity derivatives — 32,448 — 32,448 — — 32,448 PPA revenue 19,965 13,051 — 33,016 — — 33,016 Regulated solar and wind revenue — — 21,286 21,286 — — 21,286 Amortization of favorable and unfavorable rate revenue contracts, net (3,943 ) (15,624 ) — (19,567 ) — — (19,567 ) Energy revenue 108,156 133,187 21,286 262,629 — — 262,629 Incentive revenue 34,888 9,918 — 44,806 3,026 5,116 52,948 Operating revenues, net 143,044 143,105 21,286 307,435 3,026 5,116 315,577 Operating costs and expenses 302,185 — — 302,185 Operating income 5,250 3,026 5,116 13,392 Other expenses, net 105,771 — — 105,771 Loss before income tax expense (100,521 ) 3,026 5,116 (92,379 ) Income tax expense 3,404 — — 3,404 Net (loss) income $ (103,925 ) $ 3,026 $ 5,116 $ (95,783 ) Topic 606 Adoption Impact on Unaudited Condensed Consolidated Balance Sheet As of June 30, 2018 As Reported Adjustments Amounts excluding Topic 606 Adoption (In thousands) REC Sales ITC Sales Accounts receivable, net $ 161,017 $ 28,301 $ — $ 189,318 Other current assets 451,523 — — 451,523 Total current assets 612,540 28,301 — 640,841 Non-current assets 9,088,285 — — 9,088,285 Total assets $ 9,700,825 $ 28,301 $ — $ 9,729,126 Deferred revenue $ 1,735 $ — $ 16,310 $ 18,045 Other current liabilities 684,516 — — 684,516 Total current liabilities 686,251 — 16,310 702,561 Deferred revenue, less current portion 12,780 — 19,471 32,251 Other non-current liabilities 6,028,547 — — 6,028,547 Total liabilities 6,727,578 — 35,781 6,763,359 Redeemable non-controlling interests and total stockholders’ equity 2,973,247 28,301 (35,781 ) 2,965,767 Total liabilities, redeemable non-controlling interests and stockholders’ equity $ 9,700,825 $ 28,301 $ — $ 9,729,126 PPA rental income The majority of the Company’s energy revenue is derived from long-term PPAs accounted for as operating leases under ASC 840, Leases . Rental income under these leases is recorded as revenue when the electricity is delivered. The Company will adopt ASC 842, Leases on January 1, 2019. The Company is currently working through an adoption plan which includes the evaluation of lease contracts compared to the new standard and may elect certain of the practical expedients permitted in the issued standard, including the expedient that permits the Company to retain its existing lease assessment and classification. Commodity derivatives The Company has certain revenue contracts within its wind fleet that are accounted for as derivatives under the scope of ASC 815, Derivatives and Hedging . Amounts recognized within operating revenues, net in the unaudited condensed consolidated statements of operations consist of cash settlements and unrealized gains and losses representing changes in fair value for the commodity derivatives that are not designated as hedging instruments. See Note 10 . Derivatives for further discussion. PPA revenue PPAs that are not accounted for under the scope of leases or derivatives are accounted for under Topic 606. The Company typically delivers bundled goods consisting of energy and incentive products for a singular rate based on a unit of generation at a specified facility over the term of the agreement. In these type of arrangements, volume reflects total energy generation measured in kilowatt hours (“kWhs”) which can vary period to period depending on system and resource availability. The contract rate per unit of generation (kWhs) is generally fixed at contract inception; however, certain pricing arrangements can provide for time-of-delivery, seasonal or market index adjustment mechanisms over time. The customer is invoiced monthly equal to the volume of energy delivered multiplied by the applicable contract rate. The Company considers bundled energy and incentive products within PPAs to be distinct performance obligations. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied under Topic 606. The Company views the sale of energy as a series of distinct goods that is substantially the same and has the same pattern of transfer measured by the output method. Although the Company views incentive products in bundled PPAs to be performance obligations satisfied at a point in time, measurement of satisfaction and transfer of control to the customer in a bundled arrangement coincides with a pattern of revenue recognition with the underlying energy generation. Accordingly, the Company applied the practical expedient in Topic 606 as the right to consideration corresponds directly to the value provided to the customer to recognize revenue at the invoice amount for its standalone and bundled PPA contracts. For the three and six months ended June 30, 2018, the Company’s energy revenue from PPA contracts with customers was $19.8 million and $33.0 million , respectively. As of June 30, 2018, the Company’s receivable balances related to PPA contracts with customers was approximately $6.8 million . Trade receivables for PPA contracts are reflected in accounts receivable, net in the unaudited condensed consolidated balance sheets. The Company typically receives payment within 30 days for invoiced PPA revenue. The Company does not have any other significant contract asset or liability balances related to PPA revenue. Energy revenues yet to be earned under these contracts are expected to be recognized between 2018 and 2043. The Company applies the practical expedient in Topic 606 to its bundled PPA contract arrangements, and accordingly, does not disclose the value of unsatisfied performance obligations for contracts for which it recognizes revenue at the amount to which it has the right to invoice for services performed. Regulated solar and wind revenue Regulated solar and wind includes revenue generated by Saeta’s solar and wind operations in Spain, which are subject to regulations applicable to companies that generate production from renewable sources for facilities located in Spain. While Saeta’s Spanish operations are regulated by the Spanish regulator, the Company has determined that the Spanish entities do not meet the criteria of a rate regulated entity under ASC 980 Regulated Operations , since the rates established by the Spanish regulator are not designed to recover the entity’s costs of providing its energy generation services. Accordingly, the Company applied Topic 606 to recognize revenue for these customer contract arrangements. The Company has distinct performance obligations to deliver electricity, capacity, and incentives which are discussed below. The Company has a performance obligation to deliver electricity and these sales are invoiced monthly at the wholesale market price (subject to adjustments due to regulatory price bands that reduce market risk). The Company transfers control of the electricity over time and the customer receives and consumes the benefit simultaneously. Accordingly, the Company applied the practical expedient in Topic 606 as the right to consideration corresponds directly to the value provided to the customer to recognize revenue at the invoice amount for electricity sales. The Company has a stand-ready performance obligation to deliver capacity in the Spanish electricity market in which these renewable energy facilities are located. Proceeds received by the Company from the customer in exchange for capacity are determined by a return on an investment (“Ri”) per unit of installed capacity that is determined by Spanish regulators. The Company satisfies its performance obligation for capacity under a time-based measure of progress and recognizes revenue by allocating the total annual consideration evenly to each month of service. For the Company’s Spanish solar renewable energy facilities, the Company has identified a performance obligation linked to an incentive that is distinct from the electricity and capacity deliveries discussed above. For solar technologies under the Spanish market, the customer makes an operating payment (“Ro”) per MWh which is calculated based on the difference of a standard cost and an expected market price, both, determined by the Spanish regulator. The customer is invoiced monthly equal to the volume of energy produced multiplied by the regulated rate. The performance obligation is satisfied when the Company generates electricity from the solar renewable facility. Accordingly, the Company applied the practical expedient in Topic 606 and recognizes revenue based on the amount invoiced each month. Following the acquisition of Saeta, the Company is now exposed to some concentration of credit risk given that its large Spanish portfolio has only two principal offtake contract counterparties. However, this concentration of credit risk is mitigated by the investment grade credit ratings of these offtake contract counterparties. For the three and six months ended June 30, 2018, regulated solar and wind revenue with customers was $21.3 million . As of June 30, 2018, the Company’s receivable balance with customers from regulated solar and wind revenue was $77.1 million . The Company does not have any other significant contract asset or liability balances related to regulated solar and wind revenue. Amortization of favorable and unfavorable rate revenue contracts, net The Company accounts for its business combinations by recognizing in the financial statements the identifiable assets acquired, the liabilities assumed and any non-controlling interests in the acquiree at fair value at the acquisition date. Intangible amortization of certain revenue contracts acquired in business combinations (favorable and unfavorable rate PPAs and REC agreements) is recognized on a straight-line basis over the remaining contract term. The current period amortization for favorable rate revenue contracts is reflected as a reduction to operating revenues, net, and amortization for unfavorable rate revenue contracts is reflected as an increase to operating revenues, net. There was no impact related to the adoption of Topic 606. See Note 6 . Intangibles . Incentive revenue The Company generates incentive revenue from individual incentive agreements relating to the sale of RECs and performance-based incentives (“PBIs”) to third-party customers that are not bundled with the underlying energy output. The majority of individual REC sales reflect a fixed quantity, fixed price structure over a specified term. The Company views REC products in these arrangements as distinct performance obligations satisfied at a point in time. Since the REC products delivered to the customer are not linked to the underlying generation of a specified facility, these RECs are now recognized into revenue when delivered and invoiced under Topic 606. This was a change from the Company’s prior year accounting policy which recognized REC sales upon underlying electricity generation as discussed in Note 2. Summary of Significant Accounting Policies . The impact of the adoption resulted in a decrease in operating revenues, net of $5.6 million and $3.0 million during the three and six months ended June 30, 2018, respectively. Incentive revenues yet to be earned for fixed price incentive contracts are expected to be $59.8 million and recognized between 2018 and 2023. The Company typically receives payment within 30 days of invoiced REC revenue. For certain incentive contract arrangements, the quantity delivered to the customer is linked to a specific facility. Similar to PPA revenues under Topic 606, the pattern of revenue recognition for these incentive arrangements is recognized over time coinciding with the underlying revenue generation which is consistent with the Company’s policy prior to the adoption of Topic 606. For the three and six months ended June 30, 2018, the Company’s incentive revenue from facility-linked contracts with customers was $8.8 million and $14.3 million respectively. Revenue accruals for facility linked incentive contracts within accounts receivable, net were $5.8 million as of June 30, 2018. The Company applied the practical expedient in Topic 606 to its variable consideration incentive contract arrangements where revenues are linked to the underlying generation of the renewable energy facilities, and accordingly does not disclose the value of unsatisfied performance obligations for contracts for which it recognizes revenue at the amount to which it has the right to invoice for services performed. Prior to the adoption of Topic 606, the Company deferred sales of ITCs through its lease pass-through fund arrangements as a deferred revenue liability in the unaudited condensed consolidated balance sheet. As discussed in Note 2. Summary of Significant Accounting Policies , the Company now recognizes revenue related to the sales of ITCs at the point in time when the related solar energy systems are placed in service. The Company concluded that the likelihood of a recapture event related to these assessments is remote. Under Topic 605, the Company would have recognized an increase of $1.6 million and $5.1 million in non-cash deferred revenue within operating revenues, net for the three and six months ended June 30, 2018, respectively. The remaining deferred revenue balance in the unaudited condensed consolidated balance sheet as of June 30, 2018 consisted of upfront government incentives of $9.0 million and contract liabilities of $5.6 million related to performance obligations that have not yet been satisfied. These contract liabilities represent advanced customer receipts primarily related to future REC deliveries that are recognized into revenue under Topic 606. The amount of revenue recognized during the three and six months ended June 30, 2018 related to contract liabilities was $0.4 million and $0.7 million , respectively.

Acquisitions and Dispositions

Acquisitions and Dispositions	6 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
Acquisitions and Dispositions	ACQUISITIONS AND DISPOSITIONS Acquisition of Saeta On February 7, 2018, the Company announced that it intended to launch a voluntary tender offer (the “Tender Offer”) to acquire 100% of the outstanding shares of Saeta, a Spanish renewable power company with 1,028 MW of wind and solar facilities (approximately 250 MW of wind and 778 MW of solar) located primarily in Spain. The Tender Offer was for €12.20 in cash per share of Saeta. On June 8, 2018 , the Company announced that Spain’s National Securities Market Commission confirmed an over 95% acceptance of shares of Saeta in the Tender Offer (the “Tendered Shares”). On June 12, 2018, the Company completed the acquisition of the Tendered Shares for total aggregate consideration of $1.12 billion and $1.91 billion of project-level debt assumed. With 95.28% of the shares of Saeta being acquired, the Company pursued a statutory squeeze out procedure under Spanish law to procure the remaining approximately 4.72% of the shares of Saeta, which closed on July 2, 2018 . The Company funded the $1.12 billion purchase price of the Tendered Shares with $650.0 million of proceeds from the private placement of its Class A common stock to Orion Holdings and BEP as discussed in Note 1. Basis of Presentation and Note 12. Stockholders’ Equity , along with approximately $471 million from its existing liquidity, including (i) the proceeds of a $30.0 million draw on its Sponsor Line (as defined in Note 8 . Long-term Debt ), (ii) a $359.0 million draw on the Company’s Revolver (as defined in Note 8 . Long-term Debt) , and (iii) approximately $82 million of cash on hand. As discussed in Note 2. Summary of Significant Accounting Policies , the Company accounted for the acquisition of Saeta under the acquisition method of accounting for business combinations. The final accounting for the Saeta acquisition has not been completed because the evaluation necessary to assess the fair values of acquired assets and assumed liabilities is still in process. The provisional amounts for this acquisition are subject to revision until these evaluations are completed. The preliminary allocation of the acquisition-date fair values of assets, liabilities and non-controlling interests pertaining to this business combination as of June 30, 2018, were as follows: (In thousands) Saeta Renewable energy facilities in service $ 1,988,993 Accounts receivable 90,555 Intangible assets 992,883 Goodwill 115,381 Other assets 44,190 Total assets acquired 3,232,002 Accounts payable, accrued expenses and other current liabilities 92,965 Long-term debt, including current portion 1,906,831 Deferred income taxes 174,080 Asset retirement obligations 11,454 Derivative liabilities 1 137,002 Other long-term liabilities 23,069 Total liabilities assumed 2,345,401 Redeemable non-controlling interests 2 55,117 Purchase price, net of cash and restricted cash acquired 3 $ 831,484 ——— (1) Derivative liabilities are included within other long-term liabilities in the unaudited condensed consolidated balance sheets. (2) The fair value of the non-controlling interest was determined using a market approach using a quoted price for the instrument. As discussed above, the Company acquired the remaining shares of Saeta pursuant to a statutory squeeze out procedure under Spanish law, which closed on July 2, 2018 . The quoted price for the purchase of the non-controlling interest is the best indicator of fair value and was supported by a discounted cash flow technique. (3) The Company acquired cash and cash equivalents of $187.2 million and restricted cash of $95.1 million as of the acquisition date. The acquired non-financial assets primarily represent estimates of the fair value of acquired renewable energy facilities and intangible assets from concession and license agreements using the cost and income approach. Key inputs used to estimate fair value included forecasted power pricing, operational data, asset useful lives, and a discount rate factor reflecting current market conditions at the time of the acquisition. These significant inputs are not observable in the market and thus represent Level 3 measurements (as defined in Note 11 . Fair Value of Financial Instruments ). Refer below for additional disclosures related to the acquired finite-lived intangible assets. The excess of the purchase price over the estimated fair value of the net assets acquired was recorded as goodwill. The assignment of goodwill to the reporting units has not been completed. The goodwill balance is not deductible for income tax purposes. The results of operations of Saeta are included in the Company’s consolidated results since the date of acquisition. For the three and six months ended June 30, 2018, the operating revenues and net income of Saeta reflected in the unaudited condensed consolidated statements of operations were $24.7 million and $11.0 million , respectively. Intangibles at Acquisition Date The following table summarizes the estimated fair value and weighted average amortization period of acquired intangible assets as of the acquisition date for Saeta. The Company attributed intangible asset value to concessions and license agreements in-place from solar and wind facilities. These intangible assets are amortized on a straight-line basis over the estimated remaining useful life of the facility from the Company’s acquisition date. Saeta Fair Value (In thousands) Weighted Average Amortization Period (In years) 1 Intangible assets - concessions and licenses $992,883 17 years ——— (1) For purposes of this disclosure, the weighted average amortization period is determined based on a weighting of the individual intangible fair values against the total fair value for each major intangible asset and liability class. Unaudited Pro Forma Supplementary Data The unaudited pro forma supplementary data presented in the table below gives effect to the Saeta acquisition, as if the transaction had occurred on January 1, 2017. The pro forma net loss includes interest expense related to incremental borrowings used to finance the transaction and adjustments to depreciation and amortization expense for the valuation of renewable energy facilities and intangible assets. The pro forma net loss for the six months ended June 30, 2018 excludes the impact of acquisition related costs disclosed below. The unaudited pro forma supplementary data is provided for informational purposes only and should not be construed to be indicative of the Company’s results of operations had the acquisition been consummated on the date assumed or of the Company’s results of operations for any future date. Six Months Ended June 30, (In thousands) 2018 2017 Total operating revenues, net $ 496,268 $ 491,812 Net loss (90,088 ) (57,713 ) Acquisition Costs Acquisition costs incurred by the Company for the three and six months ended June 30, 2018, were $8.9 million and $12.6 million , respectively. Costs related to affiliates included in these balances were $6.0 million and $6.6 million , respectively. There were no acquisition costs incurred by the Company for the three and six months ended June 30, 2017. These costs are reflected as acquisition-related costs and acquisition and related costs - affiliate (see Note 15 . Related Parties ) in the unaudited condensed consolidated statements of operations and are excluded from the unaudited pro forma net loss amount disclosed above. U.K. Portfolio Sale On May 11, 2017, the Company announced that TerraForm Power Operating, LLC (“Terra Operating LLC”) completed its sale of substantially all of its portfolio of solar power plants located in the United Kingdom ( 24 operating projects representing an aggregate 365.0 MW, the “U.K. Portfolio”) to Vortex Solar UK Limited, a renewable energy platform managed by the private equity arm of EFG Hermes, an investment bank. Terra Operating LLC received approximately $214.1 million of proceeds from the sale, which was net of transaction expenses of $3.9 million and distributions taken from the U.K. Portfolio after announcement and before closing of the sale. The Company also disposed of $14.8 million of cash and cash equivalents and $21.8 million of restricted cash as a result of the sale. The proceeds were used for the reduction of the Company's indebtedness (a $30.0 million prepayment for a non-recourse portfolio term loan and the remainder was applied towards revolving loans outstanding under its senior secured corporate-level revolving credit facility). The sale also resulted in a reduction in the Company's non-recourse project debt by approximately £301 million British Pounds (“GBP”) at the U.K. Portfolio level. The Company recognized a gain on the sale of $37.1 million , which is reflected within gain on sale of renewable energy facilities in the unaudited condensed consolidated statements of operations for the three and six months ended June 30, 2017. The Company has retained one 11.1 MW solar asset in the United Kingdom. Residential Portfolio Sale In the first half of 2017, the Company closed on the sale of 100% of the membership interests of Enfinity Colorado DHA 1, LLC, a Colorado limited liability company that owns and operates 2.5 MW of solar installations situated on the roof of public housing units located in Colorado and owned by the Denver Housing Authority, and 100% of the membership interests of TerraForm Resi Solar Manager, LLC, a subsidiary of the Company that owns and operates 8.9 MW of rooftop solar installations, to Greenbacker Residential Solar II, LLC. The Company received proceeds of $1.1 million and $6.0 million in the second and third quarter of 2017, respectively, as a result of the sale of these companies and also disposed of $0.6 million of cash and cash equivalents and $0.8 million of restricted cash in the first half of 2017. The Company recorded an impairment charge in the fourth quarter of 2016 when it was determined that these assets met the criteria for held for sale classification, and there was no additional loss recognized during 2017 as a result of these sales.

Renewable Energy Facilities

Renewable Energy Facilities	6 Months Ended
	Jun. 30, 2018
Property, Plant and Equipment [Abstract]
Renewable Energy Facilities	RENEWABLE ENERGY FACILITIES Renewable energy facilities, net consists of the following: (In thousands) June 30, December 31, Renewable energy facilities in service, at cost 1 $ 7,316,084 $ 5,378,462 Less: accumulated depreciation - renewable energy facilities (683,260 ) (578,474 ) Renewable energy facilities in service, net 6,632,824 4,799,988 Construction in progress - renewable energy facilities 2,102 1,937 Total renewable energy facilities, net $ 6,634,926 $ 4,801,925 ——— (1) The increase in renewable energy facilities is primarily due to the acquisition of Saeta. See Note 4. Acquisitions and Dispositions . Depreciation expense related to renewable energy facilities was $57.8 million and $115.0 million for the three and six months ended June 30, 2018 , respectively, as compared to $54.4 million and $106.6 million for the same periods in the prior year. For the periods presented above, construction in progress primarily represents initial costs incurred for the construction of a new battery energy storage system for one of the Company’s wind power plants, for which construction began in the fourth quarter of 2017. Impairment Charges The Company reviews long-lived assets that are held and used for impairment whenever events or changes in circumstances indicate that the carrying amount may not be recoverable. The Company currently has a REC sales agreement with a customer expiring December 31, 2021 that is significant to an operating project within the Enfinity solar distributed generation portfolio, and on March 31, 2018, this customer filed for protection under Chapter 11 of the U.S. Bankruptcy Code. The potential replacement of this contract would likely result in a significant decrease in expected revenues for this operating project. The Company’s analysis indicated that the bankruptcy filing was a triggering event to perform an impairment evaluation, and the carrying amount of $19.5 million as of March 31, 2018 was no longer considered recoverable based on an undiscounted cash flow forecast. The Company estimated the fair value of the operating project at $4.3 million as of March 31, 2018 and recognized an impairment charge of $15.2 million equal to the difference between the carrying amount and the estimated fair value, which is reflected within impairment of renewable energy facilities in the unaudited condensed consolidated statement of operations for the six months ended June 30, 2018 . The Company used an income approach methodology of valuation to determine fair value by applying a discounted cash flow method to the forecasted cash flows of the operating project, which was categorized as a Level 3 fair value measurement due to the significance of unobservable inputs. Key estimates used in the income approach included forecasted power and incentive prices, customer renewal rates, operating and maintenance costs and the discount rate. No impairment charges were recorded for three months ended June 30, 2018. During the third quarter of 2017, the Company sold its remaining 0.3 MW of residential assets. These assets did not meet the criteria for held for sale classification in the second quarter of 2017, but the Company determined that certain impairment indicators were present and as a result recognized an impairment charge of $1.4 million , which is reflected within impairment of renewable energy facilities in the unaudited condensed consolidated statement of operations for the three and six months ended June 30, 2017 .

Intangible Assets, Net and Good

Intangible Assets, Net and Goodwill	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, Net and Goodwill	INTANGIBLE ASSETS, NET AND GOODWILL The following table presents the gross carrying amount, accumulated amortization and net book value of intangibles as of June 30, 2018 : (In thousands, except weighted average amortization period) Weighted Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Book Value Concession and licensing contracts 1 17 years $ 990,497 $ (2,953 ) $ 987,544 Favorable rate revenue contracts 14 years 713,066 (120,975 ) 592,091 In-place value of market rate revenue contracts 18 years 527,779 (86,631 ) 441,148 Favorable rate land leases 17 years 15,800 (2,729 ) 13,071 Total intangible assets, net $ 2,247,142 $ (213,288 ) $ 2,033,854 Unfavorable rate revenue contracts 7 years $ 33,686 $ (17,181 ) $ 16,505 Unfavorable rate operations and maintenance contracts 1 year 5,000 (3,177 ) 1,823 Unfavorable rate land lease 15 years 1,000 (190 ) 810 Total intangible liabilities, net 2 $ 39,686 $ (20,548 ) $ 19,138 The following table presents the gross carrying amount, accumulated amortization and net book value of intangibles as of December 31, 2017 : (In thousands, except weighted average amortization period) Weighted Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Book Value Favorable rate revenue contracts 15 years $ 718,639 $ (102,543 ) $ 616,096 In-place value of market rate revenue contracts 19 years 521,323 (73,104 ) 448,219 Favorable rate land leases 17 years 15,800 (2,329 ) 13,471 Total intangible assets, net $ 1,255,762 $ (177,976 ) $ 1,077,786 Unfavorable rate revenue contracts 7 years $ 35,086 $ (16,030 ) $ 19,056 Unfavorable rate operations and maintenance contracts 2 years 5,000 (2,552 ) 2,448 Unfavorable rate land lease 15 years 1,000 (162 ) 838 Total intangible liabilities, net 2 $ 41,086 $ (18,744 ) $ 22,342 ——— (1) See Note. 4 Acquisitions and Dispositions for a discussion of the intangible assets related to Saeta. (2) The Company’s intangible liabilities are classified within other long-term liabilities in the unaudited condensed consolidated balance sheets. Amortization expense related to favorable rate revenue contracts is reflected in the unaudited condensed consolidated statements of operations as a reduction of operating revenues, net. Amortization related to unfavorable rate revenue contracts is reflected in the unaudited condensed consolidated statements of operations as an increase to operating revenues, net. During the three and six months ended June 30, 2018 , net amortization expense related to favorable and unfavorable rate revenue contracts resulted in a reduction of operating revenues, net of $ 9.8 million and $ 19.6 million , respectively, as compared to a $9.7 million and $19.5 million reduction of operating revenues, net for the same periods in 2017. Amortization expense related to concessions and licensing contracts is reflected in the unaudited condensed consolidated statements of operations within depreciation, accretion and amortization expense. During the three and six months ended June 30, 2018, amortization expense related to concessions and licensing contracts was $2.9 million . No amortization expense was recorded for the same periods in 2017. Amortization expense related to the in-place value of market rate revenue contracts is reflected in the unaudited condensed consolidated statements of operations within depreciation, accretion and amortization expense. During the three and six months ended June 30, 2018 , amortization expense related to the in-place value of market rate revenue contracts was $10.5 million and $16.9 million , respectively, as compared to $6.6 million and $13.0 million for the same periods in the prior year. Amortization expense related to favorable rate land leases is reflected in the unaudited condensed consolidated statements of operations within cost of operations. Amortization related to the unfavorable rate land lease and unfavorable rate operations and maintenance (“O&M”) contracts is reflected in the unaudited condensed consolidated statements of operations as a reduction of cost of operations. During the three and six months ended June 30, 2018 and 2017, net amortization related to favorable and unfavorable rate land leases and unfavorable rate O&M contracts resulted in a reduction of cost of operations of $0.2 million and $0.3 million , respectively. See Note 4. Acquisitions And Dispositions for discussion of goodwill related to the Saeta acquisition.

Variable Interest Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES The Company consolidates variable interest entities (“VIEs”) in renewable energy facilities when the Company is the primary beneficiary. The VIEs own and operate renewable energy facilities in order to generate contracted cash flows. The VIEs were funded through a combination of equity contributions from the owners and non-recourse project-level debt. As a result of the Company's sale of TerraForm Resi Solar Manager, LLC, a subsidiary of the Company that owned and operated 8.9 MW of residential rooftop solar installations, during the second quarter of 2017, the related assets and liabilities of this VIE were deconsolidated. No other VIEs were deconsolidated during the six months ended June 30, 2018 and 2017 . The carrying amounts and classification of the consolidated VIEs’ assets and liabilities included in the Company’s unaudited condensed consolidated balance sheets are as follows: (In thousands) June 30, December 31, Current assets $ 131,080 $ 142,403 Non-current assets 4,062,705 4,155,558 Total assets $ 4,193,785 $ 4,297,961 Current liabilities $ 99,330 $ 119,021 Non-current liabilities 1,072,324 975,839 Total liabilities $ 1,171,654 $ 1,094,860 The amounts shown in the table above exclude intercompany balances that are eliminated upon consolidation. All of the assets in the table above are restricted for settlement of the VIE obligations, and all of the liabilities in the table above can only be settled by using VIE resources.

Long-term Debt

Long-term Debt	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Long-term Debt	LONG-TERM DEBT Long-term debt, including affiliate amounts, consists of the following: (In thousands, except rates) June 30, December 31, Interest Type Interest Rate (%) 1 Financing Type Corporate-level long-term debt - affiliate: Sponsor Line 2 $ 86,000 $ — Variable 5.05 Revolving loan Corporate-level long-term debt 3 : Senior Notes due 2023 $ 500,000 $ 500,000 Fixed 4.25 Senior notes Senior Notes due 2025 300,000 300,000 Fixed 6.63 Senior notes Senior Notes due 2028 700,000 700,000 Fixed 5.00 Senior notes Revolver 4 451,362 60,000 Variable 4.93 Revolving loan Term Loan 5 348,250 350,000 Variable 3.98 Term debt Non-recourse long-term debt 6 : Permanent financing 3,499,216 1,616,729 Blended 7 4.92 8 Term debt / Senior notes Financing lease obligations 111,548 115,787 Imputed 5.60 8 Financing lease obligations Total principal due for long-term debt and financing lease obligations 5,996,376 3,642,516 4.93 8 Unamortized discount, net (17,462 ) (19,027 ) Deferred financing costs, net (17,798 ) (24,689 ) Less: current portion of long-term debt and financing lease obligations (458,177 ) (403,488 ) Long-term debt and financing lease obligations, less current portion $ 5,502,939 $ 3,195,312 ——— (1) As of June 30, 2018 . (2) On October 16, 2017, TerraForm Power, Inc. entered into a credit agreement with Brookfield and one of its affiliates as lenders that established a $500.0 million secured revolving credit facility (the “Sponsor Line”) and provides for the lenders to commit to make LIBOR loans to the Company during a period not to exceed three years from the effective date of the agreement (subject to acceleration for certain specified events). The Company may only use the Sponsor Line to fund all or a portion of certain funded acquisitions or growth capital expenditures. (3) Corporate-level debt represents debt issued by Terra Operating LLC and guaranteed by Terra LLC and certain subsidiaries of Terra Operating LLC other than non-recourse subsidiaries as defined in the relevant debt agreements (with the exception of certain unencumbered non-recourse subsidiaries). (4) On February 6, 2018, Terra Operating LLC elected to increase the total borrowing capacity of its $450.0 million senior secured revolving credit facility (the “Revolver”), available for revolving loans and letters of credit, to $600.0 million . The balance includes $9.4 million drawn on an approximately $147.0 million revolving credit facility obtained by Saeta, as well as other credit facilities of Saeta. (5) On May 11, 2018, the Company signed a repricing amendment whereby the interest rate on the Term Loan was reduced by 0.75% per annum. (6) Non-recourse debt represents debt issued by subsidiaries with no recourse to TerraForm Power, Terra LLC, Terra Operating LLC or guarantors of the Company’s corporate-level debt, other than limited or capped contingent support obligations, which in aggregate are not considered to be material to the Company’s business and financial condition. In connection with these financings and in the ordinary course of its business, TerraForm Power and its subsidiaries observe formalities and operating procedures to maintain each of their separate existence and can readily identify each of their separate assets and liabilities as separate and distinct from each other. As a result, these subsidiaries are legal entities that are separate and distinct from TerraForm Power, Terra LLC, Terra Operating LLC and the guarantors of the Company’s corporate-level debt. (7) Includes fixed rate debt and variable rate debt. As of June 30, 2018, 74% of this balance had a fixed interest rate and the remaining 26% of this balance had a variable interest rate. The Company entered into interest rate swap agreements to fix the interest rates of a majority of the variable rate permanent financing non-recourse debt (see Note 10 . Derivatives ). (8) Represents the weighted average interest rate as of June 30, 2018. Non-recourse Debt Defaults As of June 30, 2018 and December 31, 2017, the Company reclassified $199.7 million and $239.7 million , respectively, of the Company’s non-recourse long-term indebtedness, net of unamortized debt discounts and deferred financing costs, to current in the unaudited condensed consolidated balance sheets due to defaults still remaining as of the respective financial statement issuance date, which primarily consisted of indebtedness of the Company’s renewable energy facility in Chile. The Company continued to amortize deferred financing costs and debt discounts over the maturities of the respective financing agreements as before the violations, as the Company believed there was a reasonable likelihood that it would be able to successfully negotiate a waiver with the lenders and/or cure the defaults. The Company based this conclusion on (i) its past history of obtaining waivers and/or forbearance agreements with lenders, (ii) the nature and existence of active negotiations between the Company and the respective lenders to secure a waiver, (iii) the Company’s timely servicing of these debt instruments and (iv) the fact that no non-recourse financing has been accelerated to date and no project-level lender has notified the Company of such lenders election to enforce project security interests. Refer to Note 2. Summary of Significant Accounting Policies for discussion of corresponding restricted cash reclassifications to current as a result of these defaults. There were no corresponding interest rate swap reclassifications needed as a result of these remaining defaults. Non-recourse Project Financing On June 6, 2018, one of the Company's subsidiaries entered into a new non-recourse debt financing agreement, whereby it issued $83.0 million of 4.59% senior notes, secured by approximately 73 MW of utility-scale solar power plants located in Utah, Florida, Nevada and California that are owned by the Company's subsidiary. The proceeds of this financing were used to fund a portion of the acquisition of Saeta. The non-recourse senior notes mature on August 31, 2040 and amortize on a 22 -year sculpted amortization schedule. Saeta Indebtedness In relation to the acquisition of Saeta, as discussed in Note 4. Acquisitions and Dispositions , the Company assumed total indebtedness of $1.91 billion , predominantly comprised of non-recourse project financing from commercial banks secured by Saeta’s solar and wind power plants. The interest rates applicable to this assumed indebtedness ranged from between 1.10% and 6.72% as of June 30, 2018. As of August 1, 2018, all required change of control consents in respect of this indebtedness were received by the Company. Maturities The aggregate contractual principal payments of long-term debt due after June 30, 2018 , including financing lease obligations and excluding amortization of debt discounts, premiums and deferred financing costs, as stated in the financing agreements, are as follows: (In thousands) Remainder of 2018 2019 2020 2021 2022 Thereafter Total Maturities of long-term debt $ 120,727 $ 251,675 $ 254,507 $ 696,995 $ 746,954 $ 3,925,518 $ 5,996,376 ——— (1) Represents the contractual principal payment due dates for the Company’s long-term debt and does not reflect the reclassification of $199.7 million of long-term debt to current as a result of debt defaults under certain of the Company’s non-recourse financing arrangements.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The income tax provision consisted of the following: Three Months Ended June 30, Six Months Ended June 30, (In thousands, except effective tax rate) 2018 2017 2018 2017 Loss before income tax expense (benefit) $ (23,178 ) $ (2,111 ) $ (100,521 ) $ (59,302 ) Income tax expense (benefit) 4,434 (588 ) 3,404 (1,157 ) Effective tax rate (19.1 )% 27.9 % (3.4 )% 2.0 % As of June 30, 2017 , TerraForm Power owned 65.8% of Terra LLC and consolidated the results of Terra LLC through its controlling interest. The Company recorded SunEdison’s 34.2% ownership of Terra LLC as a non-controlling interest in the financial statements. Terra LLC is treated as a partnership for income tax purposes. As such, for the six months ended June 30, 2017 , the Company recorded income tax on its 65.8% of Terra LLC’s taxable income and SunEdison recorded income tax on its 34.2% share of Terra LLC’s taxable income. On October 16, 2017, pursuant to the settlement agreement the Company entered into with SunEdison on March 6, 2017 (the “Settlement Agreement”), SunEdison transferred its interest in Terra LLC to TerraForm Power. As a result, TerraForm Power now owns 100% of the capital and profits interest in Terra LLC, except for the incentive distribution rights (“IDRs”) which are owned by BRE Delaware, Inc. (the “Brookfield IDR Holder”), an indirect wholly-owned subsidiary of Brookfield, and the Company recorded income tax on its 100% share of Terra LLC’s taxable income for the six months ended June 30, 2018 . For the three and six months ended June 30, 2018 and 2017 , the overall effective tax rate was different than the statutory rate of 21% and 35% in 2018 and 2017, respectively, primarily due to the recording of a valuation allowance on certain tax benefits attributed to the Company, loss allocated to non-controlling interests and the effect of foreign and state taxes. As of June 30, 2018 , most jurisdictions were in a gross deferred tax asset position, prior to recording any valuation allowance, except for Spain, Portugal and Uruguay (see Note 4. Acquisitions and Dispositions for deferred tax liabilities assumed in connection with the purchase of Saeta). A valuation allowance is recorded against the deferred tax assets in the U.S. (except for one portfolio), Chile and certain other jurisdictions, primarily because of the history of losses in those jurisdictions. The recognition of an income tax expense of $4.4 million and $3.4 million for the three and six months ended June 30, 2018 , respectively, was mostly driven by the income generated from the profits of Saeta in Spain and Uruguay and one of the Company’s portfolios in the U.S. As of June 30, 2018 , the Company had not identified any uncertain tax positions for which a liability was required. Due to the enactment of the Tax Act on December 22, 2017, the U.S. federal corporate income tax rate was reduced from 35% to 21% , effective January 1, 2018. As a result, the Company performed a preliminary analysis to revalue its deferred income taxes and included a net reduction in deferred liabilities of $5 million as of December 31, 2017. While the Company continues to believe that the provisional Tax Act adjustments are reasonable estimates of the effects on its existing deferred taxes, additional analysis and detailed reviews are still being performed to finalize the accounting for the re-measurement of deferred tax assets and liabilities as a result of the enactment of the Tax Act.

Derivatives

Derivatives	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	DERIVATIVES As part of the Company’s risk management strategy, the Company has entered into derivative instruments which include interest rate swaps, foreign currency contracts and commodity contracts to mitigate interest rate, foreign currency and commodity price exposure. If the Company elects to do so and if the instrument meets the criteria specified in ASC 815, Derivatives and Hedging , the Company designates its derivative instruments as cash flow hedges. The Company enters into interest rate swap agreements in order to hedge the variability of expected future cash interest payments. Foreign currency contracts are used to reduce risks arising from the change in fair value of certain foreign currency denominated assets and liabilities. The objective of these practices is to minimize the impact of foreign currency fluctuations on operating results. The Company also enters into commodity contracts to economically hedge price variability inherent in electricity sales arrangements. The objectives of the commodity contracts are to minimize the impact of variability in spot electricity prices and stabilize estimated revenue streams. The Company does not use derivative instruments for speculative purposes. As of June 30, 2018 and December 31, 2017 , fair values of the following derivative instruments were included in the balance sheet captions indicated below: Fair Value of Derivative Instruments Derivatives Designated as Hedging Instruments Derivatives Not Designated as Hedging Instruments (In thousands) Interest Rate Swaps Commodity Contracts Interest Rate Swaps Foreign Currency Contracts Commodity Contracts Gross Amounts of Assets/Liabilities Recognized Counterparty Netting Net Amounts in Consolidated Balance Sheet As of June 30, 2018 Prepaid expenses and other current assets $ 908 $ 1,200 $ — $ 46,822 $ 15,236 $ 64,166 $ (45,924 ) $ 18,242 Other assets 11,172 39,205 456 22,690 46,808 120,331 (456 ) 119,875 Total assets $ 12,080 $ 40,405 $ 456 $ 69,512 $ 62,044 $ 184,497 $ (46,380 ) $ 138,117 Accounts payable, accrued expenses and other current liabilities $ 600 $ — $ 35,345 $ 56,870 $ — $ 92,815 $ (45,924 ) $ 46,891 Other long-term liabilities 2,152 — 90,660 — — 92,812 (456 ) 92,356 Total liabilities $ 2,752 $ — $ 126,005 $ 56,870 $ — $ 185,627 $ (46,380 ) $ 139,247 As of December 31, 2017 Prepaid expenses and other current assets $ — $ 8,961 $ — $ 63 $ 12,609 $ 21,633 $ (63 ) $ 21,570 Other assets 4,686 71,307 — — 14,787 90,780 — 90,780 Total assets $ 4,686 $ 80,268 $ — $ 63 $ 27,396 $ 112,413 $ (63 ) $ 112,350 Accounts payable, accrued expenses and other current liabilities $ 2,490 $ — $ 197 $ 99 $ — $ 2,786 $ (63 ) $ 2,723 Other long-term liabilities 4,796 — 404 — — 5,200 — 5,200 Total liabilities $ 7,286 $ — $ 601 $ 99 $ — $ 7,986 $ (63 ) $ 7,923 As of June 30, 2018 and December 31, 2017 , notional amounts for derivative instruments consisted of the following: Notional Amount as of (In thousands) June 30, 2018 December 31, 2017 Derivatives designated as hedging instruments: Interest rate swaps (USD) 371,560 395,986 Interest rate swaps (CAD) 151,778 156,367 Commodity contracts (MWhs) 6,334 15,579 Derivatives not designated as hedging instruments: Interest rate swaps (USD) 13,132 13,520 Foreign currency contracts (CAD) — 9,875 Interest rate swaps (EUR) 1,065,137 — Foreign currency contracts (EUR) 3,395,200 — Commodity contracts (MWhs) 9,247 987 The Company elected to present net derivative assets and liabilities on the balance sheet as a right to set-off exists. For interest rate swaps, the Company either nets derivative assets and liabilities on a trade-by-trade basis or nets them in accordance with a master netting arrangement if such an arrangement exists with the counterparties. Foreign currency contracts are netted by currency in accordance with a master netting arrangement. The Company has a master netting arrangement for its commodity contracts for which no amounts were netted as of June 30, 2018 or December 31, 2017. Gains and losses on derivatives not designated as hedging instruments for the three and six months ended June 30, 2018 and 2017 consisted of the following: Location of Loss (Gain) in the Statements of Operations Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2018 2017 2018 2017 Interest rate swaps Interest expense, net $ (7,763 ) $ 1,818 $ (7,989 ) $ 3,192 Foreign currency contracts (Gain) loss on foreign currency exchange, net (13,792 ) 347 (12,566 ) 560 Commodity contracts Operating revenues, net (17,084 ) (1,579 ) (17,494 ) (5,692 ) During the second quarter of 2018, the Company discontinued hedge accounting for certain long-dated commodity contracts as they were no longer considered highly effective in offsetting the cash flows associated with the underlying risk being hedged. Long-term electricity prices in the related market declined significantly during the second quarter of 2018, causing the derivative contracts to have intrinsic value and thus negatively impacting the effectiveness of the intrinsic value being hedged. Hedge accounting was prospectively discontinued effective April 1, 2018, with changes in fair value recorded in earnings. The gains in AOCI as of March 31, 2018, which amounted to $44.3 million , are currently being amortized through earnings over the term of these contracts, the last of which expires in 2023. The balance of the accumulated gains deferred in AOCI as of June 30, 2018, was $42.1 million . During the three and six months ended June 30, 2018, the total gains related to these commodity contracts were $17.1 million and $23.6 million , respectively, recorded in the unaudited condensed consolidated statement of operations within operating revenue, net, as compared to $5.8 million and $11.2 million for the same periods in the prior year. Gains and losses recognized related to interest rate swaps and commodity contracts designated as hedging instruments for the three and six months ended June 30, 2018 and 2017 consisted of the following: Three Months Ended June 30, Derivatives in Cash Flow Hedging Relationships Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, net of taxes 1 Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach 2 Location of Amount Reclassified from AOCI into Income (Gain) Loss Included in the Assessment of Effectiveness Reclassified from AOCI into Income 3 (Gain) Loss Excluded from the Assessment of Effectiveness that is Amortized through Earnings 2 (In thousands) 2018 2017 2018 2017 2018 2017 Interest rate swaps $ 2,645 $ (1,633 ) $ — $ — Interest expense, net $ 292 $ (217 ) $ — $ (322 ) Commodity contracts 11,623 (1,799 ) — — Operating revenues, net (731 ) (18 ) (347 ) 2,894 Total $ 14,268 $ (3,432 ) $ — $ — $ (439 ) $ (235 ) $ (347 ) $ 2,572 ———— (1) Net of tax benefit of zero and $0.5 million attributed to interest rate swaps during the three months ended June 30, 2018 and 2017, respectively. Net of tax benefit of zero and $3.7 million attributed to commodity contracts during the three months ended June 30, 2018 and 2017, respectively. (2) As a result of the adoption of ASU No. 2017-12 effective January 1, 2018 (see Note 2. Summary of Significant Accounting Policies ), certain gains and losses were excluded from the assessment of effectiveness that are being amortized through earnings for the three months ended June 30, 2018. No such amounts existed for the three months ended June 30, 2017 prior to the adoption of ASU No. 2017-12. (3) Net of tax benefit of zero and $1.7 million attributed to interest rate swaps during the three months ended June 30, 2018 and 2017, respectively. Net of tax expense of zero and $2.1 million attributed to commodity contracts during the three months ended June 30, 2018 and 2017, respectively. Six Months Ended June 30, Derivatives in Cash Flow Hedging Relationships Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, net of taxes 1 Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach 2 Location of Amount Reclassified from AOCI into Income (Gain) Loss Included in the Assessment of Effectiveness Reclassified from AOCI into Income 3 (Gain) Loss Excluded from the Assessment of Effectiveness that is Amortized through Earnings 2 (In thousands) 2018 2017 2018 2017 2018 2017 2018 2017 Interest rate swaps $ 10,520 $ (3,252 ) — $ — Interest expense, net $ 973 $ 2,644 $ — $ 491 Commodity contracts (7,479 ) 13,874 735 — Operating revenues, net (2,042 ) (3,265 ) (679 ) 3,083 Total $ 3,041 $ 10,622 $ 735 $ — $ (1,069 ) $ (621 ) $ (679 ) $ 3,574 ———— (1) Net of tax benefit of zero and $0.5 million attributed to interest rate swaps during the six months ended June 30, 2018 and 2017, respectively. Net of tax expense of zero and $2.1 million attributed to commodity contracts during the six months ended June 30, 2018 and 2017, respectively. (2) As a result of the adoption of ASU No. 2017-12 effective January 1, 2018 (see Note 2. Summary of Significant Accounting Policies ), certain gains and losses were excluded from the assessment of effectiveness that are being amortized through earnings for the six months ended June 30, 2018. No such amounts existed for the six months ended June 30, 2017 prior to the adoption of ASU No. 2017-12. (3) Net of tax benefit of zero and $1.7 million attributed to interest rate swaps during the six months ended June 30, 2018 and 2017, respectively. Net of tax expense of zero and $2.1 million attributed to commodity contracts during the six months ended June 30, 2018 and 2017, respectively. As discussed in Note 2. Summary of Significant Accounting Policies , the Company adopted ASU No. 2017-12 as of January 1, 2018 and recognized a cumulative-effect adjustment of $4.2 million , net of tax of $1.6 million , representing a decrease in beginning accumulated deficit and AOCI, which is reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018. As of June 30, 2018 and December 31, 2017 , the Company had posted letters of credit in the amount of $15.0 million , as collateral related to certain commodity contracts. Certain derivative contracts contain provisions providing the counterparties a lien on specific assets as collateral. There was no cash collateral received or pledged as of June 30, 2018 and December 31, 2017 related to the Company’s derivative transactions. Derivatives Designated as Hedging Instruments Interest Rate Swaps The Company has interest rate swap agreements to hedge variable rate non-recourse debt. These interest rate swaps were designated as hedging instruments and qualify for hedge accounting. Under the interest rate swap agreements, the renewable energy facilities pay a fixed rate and the counterparties to the agreements pay a variable interest rate. The amounts deferred in AOCI and reclassified into e arnings during the three and six months ended June 30, 2018 and 2017 related to these interest rate swaps are provided in the tables above. The gain expected to be reclassified into earnings over the next twelve months is approximately $0.4 million . The maximum term of outstanding interest rate swaps designated as hedging instruments is 16 years. Commodity Contracts The Company has long-dated physically delivered commodity contracts that hedge variability in cash flows associated with the sales of power from certain renewable energy facilities located in Texas. These commodity contracts qualify for hedge accounting and are designated as cash flow hedges. Accordingly, the effective portions of the change in fair value of these derivatives are reported in AOCI and subsequently reclassified to earnings in the periods when the hedged transactions affect earnings. Prior to adoption of ASU 2017-12, any ineffective portions of the derivatives’ change in fair value were recognized in earnings. The amounts deferred in AOCI and reclassified into earnings during the three and six months ended June 30, 2018 and 2017 related to these commodity contracts are provided in the ta bles above. The gain expected to be reclassified into earnings over the next twelve months is approximately $1.6 million . The maximum term of outstanding commodity contracts designated as hedges is 10 years. Derivatives Not Designated as Hedging Instruments Interest Rate Swaps The Company has interest rate swap agreements that economically hedge the cash flows for non-recourse debt. These interest rate swaps pay a fixed rate and the counterparties to the agreements pay a variable interest rate. The changes in fair value are recorded in interest expense, net in the unaudited condensed consolidated statements of operations as these hedges are not accounted for under hedge accounting. Foreign Currency Contracts The Company has foreign currency contracts in order to economically hedge its exposure to foreign currency fluctuations. The settlement of these hedges occurs on a quarterly basis through maturity. As these hedges are not accounted for under hedge accounting, the changes in fair value are recorded in gain on foreign currency exchange, net in the unaudited condensed consolidated statements of operations. Commodity Contracts The Company has commodity contracts in order to economically hedge commodity price variability inherent in certain electricity sales arrangements. If the Company sells electricity to an independent system operator market and there is no PPA available, it may enter into a commodity contract to hedge all or a portion of their estimated revenue stream. These commodity contracts require periodic settlements in which the Company receives a fixed-price based on specified quantities of electricity and pays the counterparty a variable market price based on the same specified quantity of electricity. As these hedges are not accounted for under hedge accounting, the changes in fair value are recorded in operating revenues net, in the unaudited condensed consolidated statements of operations.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS The fair value of assets and liabilities are determined using either unadjusted quoted prices in active markets (Level 1) or pricing inputs that are observable (Level 2) whenever that information is available and using unobservable inputs (Level 3) to estimate fair value only when relevant observable inputs are not available. The Company uses valuation techniques that maximize the use of observable inputs. Assets and liabilities are classified in their entirety based on the lowest priority level of input that is significant to the fair value measurement. Where observable inputs are available for substantially the full term of the asset or liability, the instrument is categorized in Level 2. If the inputs into the valuation are not corroborated by market data, in such instances, the valuation for these contracts is established using techniques including extrapolation from or interpolation between actively traded contracts, as well as calculation of implied volatilities. When such inputs have a significant impact on the measurement of fair value, the instrument is categorized as Level 3. The Company regularly evaluates and validates the inputs used to determine fair value of Level 3 contracts by using pricing services to support the underlying market price of the commodity. The Company uses a discounted cash flow valuation technique to fair value its derivative assets and liabilities. The primary inputs in the valuation models for commodity contracts are market observable forward commodity curves and risk-free discount rates and to a lesser degree credit spreads and volatilities. The primary inputs into the valuation of interest rate swaps and foreign currency contracts are forward interest rates and foreign currency exchange rates and to a lesser degree credit spreads. Recurring Fair Value Measurements The following table summarizes the financial instruments measured at fair value on a recurring basis classified in the fair value hierarchy (Level 1, 2 or 3) based on the inputs used for valuation in the unaudited condensed consolidated balance sheets: (In thousands) As of June 30, 2018 As of December 31, 2017 Assets Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Interest rate swaps $ — $ 12,080 $ — $ 12,080 $ — $ 4,686 $ — $ 4,686 Commodity contracts — 20,590 81,859 102,449 — 27,396 80,268 107,664 Foreign currency contracts — 23,588 — 23,588 — — — — Total derivative assets $ — $ 56,258 $ 81,859 $ 138,117 $ — $ 32,082 $ 80,268 $ 112,350 Liabilities Interest rate swaps $ — $ 128,301 $ — $ 128,301 $ — $ 7,887 $ — $ 7,887 Commodity contracts — — — — — — — — Foreign currency contracts — 10,946 — 10,946 — 36 — 36 Total derivative liabilities $ — $ 139,247 $ — $ 139,247 $ — $ 7,923 $ — $ 7,923 The Company's interest rate swaps, commodity contracts not designated as hedges and foreign currency contracts are considered Level 2, since all significant inputs are corroborated by market observable data. The Company's commodity contracts designated as hedges are considered Level 3 as they contain significant unobservable inputs. There were no transfers in or out of Level 1, Level 2 and Level 3 during the six months ended June 30, 2018 . The following table reconciles the changes in the fair value of derivative instruments classified as Level 3 in the fair value hierarchy for the three and six months ended June 30, 2018 and 2017: Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2018 2017 2018 2017 Beginning balance $ 60,148 $ 87,318 $ 80,268 $ 66,138 Realized and unrealized gains (losses): Included in other comprehensive income (loss) 9,503 (7,634 ) (10,507 ) 10,628 Included in operating revenues, net 14,016 (741 ) 15,549 5,424 Settlements (1,808 ) (2,153 ) (3,451 ) (5,400 ) Balance as of June 30 $ 81,859 $ 76,790 $ 81,859 $ 76,790 The significant unobservable inputs used in the valuation of the Company's commodity contracts categorized as Level 3 in the fair value hierarchy as of June 30, 2018 are as follows: (In thousands, except range) Fair Value as of Transaction Type Assets Liabilities Valuation Technique Unobservable Inputs Range Commodity contracts - power $ 81,859 $ — Discounted cash flow Forward price (per MWh) $ 11.4 - $ 125.5 Option model Volatilities 3.0 % - 7.4 % The sensitivity of the Company’s fair value measurements to increases (decreases) in the significant unobservable inputs is as follows: Significant Unobservable Input Position Impact on Fair Value Measurement Increase (decrease) in forward price Forward sale Decrease (increase) Increase (decrease) in implied volatilities Purchase option Increase (decrease) The Company measures the sensitivity of the fair value of its Level 3 commodity contracts to potential changes in commodity prices using a mark-to-market analysis based on the current forward commodity prices and estimates of the price volatility. An increase in power forward prices will produce a mark-to-market loss, while a decrease in prices will result in a mark-to-market gain. Fair Value of Debt The carrying amount and estimated fair value of the Company's long-term debt as of June 30, 2018 and December 31, 2017 is as follows: As of June 30, 2018 As of December 31, 2017 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt $ 5,961,116 $ 6,056,039 $ 3,598,800 $ 3,702,470 The fair value of the Company's long-term debt, except the corporate-level senior notes, was determined using inputs classified as Level 2 and a discounted cash flow approach using market rates for similar debt instruments. The fair value of the corporate-level senior notes is based on market price information which is classified as a Level 1 input. They are measured using the last available trades at the end of each respective fiscal year. The fair value of the Senior Notes due 2023, Senior Notes due 2025 and Senior Notes due 2028 were 96.50% , 106.25% and 95.00% of face value as of June 30, 2018 , respectively, and 99.50% , 109.50% and 99.38% of face value as of December 31, 2017, respectively.

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY The following table reflects the changes in TerraForm Power’s Class A common shares outstanding during the six months ended June 30, 2018 and 2017: Six Months Ended June 30, 2018 2017 Balance as of January 1 148,086,027 92,223,089 Issuance of Class A common stock to affiliates 60,975,609 — Shares issued under equity incentive plan — 45,385 Balance as of June 30 209,061,636 92,268,474 Issuance of Class A Common Stock to Affiliates On June 11, 2018, TerraForm Power entered into a Class A Common Stock Purchase Agreement (“Share Purchase Agreement”) with Orion Holdings and BEP (collectively, the “Purchasers”), both affiliates of Brookfield. Pursuant to the Share Purchase Agreement, the Purchasers purchased in a private placement a total of 60,975,609 shares of TerraForm Power’s Class A common stock for a price per share of $10.66 , representing total consideration of approximately $650.0 million . No underwriting discounts or commissions were paid with respect to this private placement. These newly issued shares of TerraForm Power, Inc. were not registered with the SEC in reliance on Section 4(a)(2) of the Securities Act and the acknowledgment of each of the Purchasers that it is an “accredited investor” within the meaning of Rule 501(a) of Regulation D of the Securities Act or a “qualified institutional buyer” under Rule 144A of the Securities Act. As a result of this private placement, affiliates of Brookfield now hold approximately 65% of TerraForm Power Inc.’s Class A common stock. The proceeds of the offering were used by the Company to pay a portion of the purchase price of the Tendered Shares of Saeta. The purchase of TerraForm Power, Inc. Class A shares by the Purchasers was made in accordance with the support agreement that the Company entered into with Brookfield, dated February 6, 2018, and amended on May 28, 2018, pursuant to which Brookfield agreed to backstop a share offering of TerraForm Power, Inc.’s Class A common stock in an amount up to $650.0 million and at a price of $10.66 per share. Stock-based Compensation The Company has an equity incentive plan that provides for the award of incentive and nonqualified stock options, restricted stock awards (“RSAs”) and restricted stock units (“RSUs”) to personnel and directors who provide services to the Company. The maximum contractual term of an award is ten years from the date of grant. As of June 30, 2018, an aggregate of 3,808,697 shares of Class A common stock were available for issuance under this plan. Upon exercise of stock options or the vesting of RSUs, the Company will issue shares that have been previously authorized to be issued. During the six months ended June 30, 2018, the Company awarded 117,424 time-based RSUs to certain employees of the Company. The grant-date fair value of these awards was $1.3 million , which was calculated based on the Company's closing stock price on the date of grant, and will be recognized as compensation cost on a straight-line basis over the three year service period. The amount of stock-based compensation expense related to the equity awards in the Company's stock was $0.1 million during the three and six months ended June 30, 2018, as compared to $1.8 million and $3.3 million for the same periods in the prior year, respectively, and is reflected in the unaudited condensed consolidated statement of operations within general and administrative expenses. RSUs will not entitle the holders to voting rights and holders of the RSUs will not have any right to receive dividends or distributions. The following table presents information regarding outstanding RSUs as of June 30, 2018 and changes during the six months ended June 30, 2018: Number of RSUs Outstanding Aggregate Intrinsic Value (in millions) Weighted Average Remaining Balance as of January 1, 2018 — Granted 117,424 Balance as of June 30, 2018 117,424 $ 0.2 2.8 years Dividends The following table presents cash dividends declared and paid on Class A common stock during the six months ended June 30, 2018. TerraForm Power did not declare or pay a dividend during the six months ended June 30, 2017. Dividends per Share Declaration Date Record Date Payment Date First Quarter $ 0.19 February 6, 2018 February 28, 2018 March 30, 2018 Second Quarter 0.19 April 30, 2018 June 1, 2018 June 15, 2018

(Loss) Earnings Per Share

(Loss) Earnings Per Share	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
(Loss) Earnings Per Share	(LOSS) EARNINGS PER SHARE Basic (loss) earnings per share is computed by dividing net (loss) income attributable to Class A common stockholders by the number of weighted average ordinary shares outstanding during the period, which is the average of shares outstanding and assumed to be outstanding, and includes contingently issuable shares as of the date when the contingent condition has been met. Diluted (loss) earnings per share is computed by adjusting basic earnings (loss) per share for the impact of weighted average dilutive common equivalent shares outstanding during the period, unless the impact is anti-dilutive. Common equivalent shares include the incremental shares issuable for unvested restricted Class A common stock and contingently issuable shares in the period the contingency has been met, for the portion of the period prior to the resolution of such contingent condition. Basic and diluted (loss) earnings per share of the Company's Class A common stock for the three and six months ended June 30, 2018 and 2017 was calculated as follows: Three Months Ended June 30, Six Months Ended June 30, (In thousands, except per share amounts) 2018 2017 2018 2017 Basic and diluted earnings (loss) per share: Net (loss) income attributable to Class A common stockholders $ (21,337 ) $ 9,606 $ 61,459 $ (21,191 ) Less: accretion of redeemable non-controlling interest — (2,187 ) — (4,413 ) Net (loss) income attributable to Class A common stockholders after accretion of redeemable non-controlling interests $ (21,337 ) $ 7,419 $ 61,459 $ (25,604 ) Weighted average basic Class A shares outstanding 1 161,568 92,257 154,890 92,165 Weighted average diluted Class A shares outstanding 2,3 161,568 92,745 154,905 92,165 Basic and diluted (loss) earnings per share $ (0.13 ) $ 0.08 $ 0.40 $ (0.28 ) ——— (1) Includes zero and 66 thousand contingently issuable shares for the three and six months ended June 30, 2018, respectively. (2) Includes zero and 29 thousand additional contingently issuable shares for the three and six months ended June 30, 2018, respectively. (3) The computation of diluted loss per share of the Company's Class A common stock for the three months ended June 30, 2018, excludes 117 thousand of potentially dilutive unvested RSUs because the effect would have been anti-dilutive. The computation of diluted earnings per share of the Company's Class A common stock for the six months ended June 30, 2018, includes 15 thousand of RSUs considered to be dilutive and calculated using the treasury stock method. The computation of diluted earnings per share of the Company's Class A common stock for the three months ended June 30, 2017 includes 487,950 of RSUs considered to be dilutive and calculated using the treasury stock method. The computation of diluted loss per share of the Company's Class A common stock for the six months ended June 30, 2017 excludes 1,524,317 of potentially dilutive unvested RSUs because the effect would have been anti-dilutive.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Letters of Credit The Company’s customers, vendors and regulatory agencies often require the Company to post letters of credit in order to guarantee performance under relevant contracts and agreements. The Company is also required to post letters of credit to secure obligations under various swap agreements and leases and may, from time to time, decide to post letters of credit in lieu of cash deposits in reserve accounts under certain financing arrangements. The amount that can be drawn under some of these letters of credit may be increased from time to time subject to the satisfaction of certain conditions. As of June 30, 2018, the Company had outstanding letters of credit under the Revolver of $78.8 million and outstanding project-level letters of credit of $156.9 million . In connection with the Company’s launch of the Tender Offer for the outstanding shares of Saeta discussed in Note 4. Acquisitions and Dispositions , the Company was required to post a bank guarantee (the “Bank Guarantee”) with the Spanish National Securities Market Commission (Comisión Nacional del Mercado de Valores, the “CNMV”) for the maximum amount payable in the tender offer of approximately $1.2 billion . On March 6, 2018, TERP Spanish HoldCo S.L. (“TERP Spanish HoldCo”), a subsidiary of the Company, entered into two letter of credit facilities (the “LC Agreements”) pursuant to which two banks posted the Bank Guarantee with the CNMV. On March 6, 2018, TerraForm Power entered into two letter agreements (the “Letter Agreements” and together with the LC Agreements, the “Letter of Credit Facilities”) with those banks. The LC Agreements governed TERP Spanish HoldCo’s obligations to reimburse those banks upon any drawing under the Bank Guarantee, and the Letter Agreements governed TerraForm Power’s obligation to utilize drawings on its Revolver and Sponsor Line or proceeds from an equity offering of its Class A common stock to contribute funds to TERP Spanish HoldCo to enable TERP Spanish HoldCo to satisfy its reimbursement obligations under the LC Agreements. As a result of the Company’s payment of (i) $1.12 billion for greater than 95% of the Tendered Shares on June 12, 2018 and (ii) $54.6 million for the remaining 4.72% of the Tendered Shares on July 2, 2018, the payment obligations under the Bank Guarantee and the LC Agreements were canceled and no amounts remain outstanding thereunder. The Company funded the $54.6 million payment by additional draw downs on the Sponsor Line from Brookfield. Guarantee Agreements The Company and its subsidiaries have provided guarantees to certain of its institutional tax equity investors and financing parties in connection with its tax equity financing transactions. These guarantees do not guarantee the returns targeted by the tax equity investors or financing parties, but rather support any potential indemnity payments payable under the tax equity agreements, including related to management of tax partnerships and recapture of tax credits or renewable energy grants in connection with transfers of the Company’s direct or indirect ownership interests in the tax partnerships to entities that are not qualified to receive those tax benefits. The Company and its subsidiaries have also provided guarantees in connection with acquisitions of third party assets or to support project contractual obligations, including renewable energy credit sales agreements. The Company and its subsidiaries have also provided other capped or limited contingent guarantees and other support obligations with respect to certain project-level indebtedness. See above for discussion regarding the Bank Guarantee that was posted in connection with the Company’s tender offer for the outstanding shares of Saeta. Legal Proceedings The Company is not a party to any material legal proceedings other than various administrative and regulatory proceedings arising in the ordinary course of the Company’s business or as described below. While the Company cannot predict with certainty the ultimate resolution of such proceedings or other claims asserted against the Company, certain of the claims, if adversely concluded, could result in substantial damages or other relief. Securities Class Action On April 4, 2016, a securities class action under federal securities laws (Chamblee v. TerraForm Power, Inc., et al., Case No. 1:16-cv-00981-JFM) (the “Chamblee Class Action”) was filed in the United States District Court for the District of Maryland against the Company and two of its former officers ( one of which was also a director of the Company at the time) asserting claims under Section 10(b) and 20(a) of the Exchange Act and SEC Rule 10b-5 on behalf of a putative class. The complaint alleged that the defendants made materially false and misleading statements regarding the Company’s business, operational and compliance policies, including with respect to disclosures regarding SunEdison’s internal controls and the Company’s reliance on SunEdison. The U.S. District Court for the Southern District of New York (“SDNY”) entered an order requiring all parties to the multidistrict litigation to mediate and entered a partial stay of all proceedings through March 31, 2017. After mediation, the parties agreed in principle to a settlement of $14.8 million on behalf of a putative settlement class containing all persons and entities that purchased or otherwise acquired the publicly traded securities of the Company between July 18, 2014 and March 15, 2016, expressly conditioned on, among other things, funding of the settlement by the Company’s directors’ and officers’ liability insurance providers in the amount of $13.6 million . The Company reserved $1.1 million for its estimated probable loss related to this complaint as of December 31, 2016, which was the amount the Company would have been prepared to fund the settlement out of its own funds. On September 14, 2017, the SDNY preliminarily approved the settlement. As of December 31, 2017, the Company recorded an insurance receivable of $13.6 million within prepaid expenses and other current assets and a corresponding additional liability of $13.6 million within accounts payable, accrued expenses and other current liabilities in the consolidated balance sheet. In January of 2018, the insurers funded $13.6 million and the Company funded $1.1 million into the settlement escrow account. The settlement was finally approved at a hearing of the court on January 31, 2018 and was paid by the Company in the first quarter of 2018. Claim relating to First Wind Acquisition On May 27, 2016, D.E. Shaw Composite Holdings, L.L.C. and Madison Dearborn Capital Partners IV, L.P., as the representatives of the sellers (the “First Wind Sellers”) filed an amended complaint for declaratory judgment against TerraForm Power and Terra LLC in the Supreme Court of the State of New York alleging breach of contract with respect to the Purchase and Sale Agreement, dated as of November 17, 2014 (the “FW Purchase Agreement”) between, among others, SunEdison, TerraForm Power and Terra LLC and the First Wind Sellers. The amended complaint alleges that Terra LLC and SunEdison became jointly obligated to make $231.0 million in earn-out payments in respect of certain development assets SunEdison acquired from the First Wind Sellers under the FW Purchase Agreement, when those payments were purportedly accelerated by SunEdison’s bankruptcy and by the resignations of two SunEdison employees. The amended complaint further alleges that TerraForm Power, as guarantor of certain Terra LLC obligations under the FW Purchase Agreement, is liable for this sum. The defendants filed a motion to dismiss the amended complaint on July 5, 2016, on the ground that, among other things, SunEdison is a necessary party to this action. The plaintiffs filed an opposition to the motion to dismiss on August 22, 2016. The defendants filed their reply on September 12, 2016. A hearing on the motion to dismiss took place on January 24, 2017. On February 6, 2018, the court denied the Company’s motion to dismiss, and discovery is proceeding in the case. The Company cannot predict the impact on this litigation of any information that may become available in discovery. The Company believes the First Wind Sellers’ allegation is without merit and will contest the claim and allegations vigorously. However, the Company cannot predict with certainty the ultimate resolution of any proceedings brought in connection with such a claim. Whistleblower Complaint By Francisco Perez Gundin On May 18, 2016, the Company’s former Director and Chief Operating Officer, Francisco Perez Gundin (“Mr. Perez”), filed a complaint against the Company, TerraForm Global, Inc. and certain individuals, with the United States Department of Labor. The complaint alleges that the defendants engaged in a retaliatory termination of Mr. Perez’s employment after he allegedly voiced concerns to SunEdison’s Board of Directors about public representations made by SunEdison officers regarding SunEdison’s liquidity position, and after he allegedly voiced his opposition to transactions that he alleges were self-interested and which he alleges SunEdison forced on the Company. He alleges that the Company participated in SunEdison’s retaliatory termination by constructively terminating his position as Chief Operating Officer of the Company in connection with SunEdison’s constructive termination of his employment. He seeks lost wages, bonuses, benefits, and other money that he alleges that he would have received if he had not been subjected to the allegedly retaliatory termination. The Company’s Position Statement in response to the complaint was filed in October of 2016. On February 21, 2017, Mr. Perez filed Gundin v. TerraForm Global, Inc. et al. against TerraForm Power, TerraForm Global, Inc. and certain individuals as defendants in the United States District Court for the District of Maryland. The complaint asserts claims for retaliation, breach of the implied covenant of good faith and fair dealing and promissory estoppel based on the same allegation in Mr. Perez’s Department of Labor complaint. On March 15, 2017, the Company filed notice with the Judicial Panel on Multidistrict Litigation to transfer this action to the SDNY where the Chamblee Class Action was tried and other cases not involving the Company relating to the SunEdison bankruptcy are being tried. The plaintiff did not oppose the transfer, which was approved by the Judicial Panel on Multidistrict Litigation. On November 6, 2017, TerraForm Power and the other defendants filed a motion to dismiss Mr. Perez’s complaint, and Mr. Perez filed a response on December 21, 2017. On March 8, 2018, Mr. Perez voluntarily dismissed the federal action without prejudice, which would permit the action to be refiled. The proceeding before the Department of Labor has not been dismissed. The Company reserved for its estimated loss related to this complaint in 2016, which was not considered material to the Company’s consolidated results of operations, and this amount remains accrued as of June 30, 2018. However, the Company is unable to predict with certainty the ultimate resolution of these proceedings. Whistleblower Complaint By Carlos Domenech Zornoza On May 10, 2016, the Company’s former Director and Chief Executive Officer, Carlos Domenech Zornoza (“Mr. Domenech”), filed a complaint against the Company, TerraForm Global, Inc. and certain individuals, with the United States Department of Labor. The complaint alleges that the defendants engaged in a retaliatory termination of Mr. Domenech’s employment on November 20, 2015 after he allegedly voiced concerns to SunEdison’s Board of Directors about public representations made by SunEdison officers regarding SunEdison’s liquidity position, and after he allegedly voiced his opposition to transactions that he alleges were self-interested and which he alleges SunEdison forced on the Company. He alleges that the Company participated in SunEdison’s retaliatory termination by terminating his position as Chief Executive Officer of the Company in connection with SunEdison’s termination of his employment. He seeks lost wages, bonuses, benefits, and other money that he alleges that he would have received if he had not been subjected to the allegedly retaliatory termination. The Company’s Position Statement in response to the complaint was filed in October of 2016. On February 21, 2017, Mr. Domenech filed Domenech Zornoza v. TerraForm Global, Inc. et. al against TerraForm Power, TerraForm Global, Inc. and certain individuals as defendants in the United States District Court for the District of Maryland. The complaint asserts claims for retaliation, breach of the implied covenant of good faith and fair dealing and promissory estoppel based on the same allegations in Mr. Domenech’s Department of Labor complaint. On March 15, 2017, the Company filed notice with the Judicial Panel on Multidistrict Litigation to transfer this action to the SDNY where the Chamblee Class Action was tried and other cases not involving the Company relating to the SunEdison bankruptcy are being tried. The plaintiff opposed the transfer. However, the transfer was approved by the Judicial Panel on Multidistrict Litigation. On November 6, 2017, TerraForm Power and the other defendants filed a motion to dismiss Mr. Domenech’s complaint, and Mr. Domenech filed a response on December 21, 2017. On March 8, 2018, Mr. Domenech voluntarily dismissed the federal action without prejudice, which would permit the action to be refiled. The proceeding before the Department of Labor has not been dismissed. The Company reserved for its estimated loss related to this complaint in 2016, which was not considered material to the Company’s consolidated results of operations, and this amount remains accrued as of June 30, 2018. However, the Company is unable to predict with certainty the ultimate resolution of these proceedings. Chile Project Arbitration On September 5, 2016, Compañía Minera del Pacífico (“CMP”) submitted demands for arbitration against the subsidiary of the Company which owns its renewable energy project located in Chile and against the latter’s immediate holding company to the Santiago Chamber of Commerce’s Center for Arbitration and Mediation (“CAM”). The demands allege, among other things, that the Chile project was not built, operated and maintained according to the relevant standards using prudent utility practices as required by the electricity supply agreement (the “Contract for Difference”) between the parties, entitling them to terminate the Contract for Difference. CMP further alleges that it is entitled to damages based on alleged breaches of a call option agreement entered into by the parties. Both respondents delivered their initial responses to the CAM on November 7, 2016. The proceedings are currently in the evidentiary phase. The Company believes these claims are without merit and intends to continue to contest them vigorously. However, the Company cannot predict with certainty the ultimate resolution of the arbitral proceedings brought in connection with these claims. Issuance of Shares upon Final Resolution of Certain Litigation Matters Pursuant to the definitive merger and sponsorship transaction agreement (the “Merger Agreement”) entered into with Orion Holdings on March 6, 2017, the Company has agreed to issue additional shares of Class A common stock to Orion Holdings for no additional consideration in respect of the Company’s net losses, such as out-of-pocket losses, damages, costs, fees and expenses, in connection with the obtainment of a final resolution of certain specified litigation matters (being the Chamblee Class Action and the litigation brought by the First Wind Sellers, Mr. Perez and Mr. Domenech described above) within a prescribed period following the final resolution of such matters. The number of additional shares of Class A common stock to be issued to Orion Holdings is subject to a pre-determined formula as set forth in the Merger Agreement and is described in greater detail in the Company’s Definitive Proxy Statement filed on Schedule 14A with the SEC on September 6, 2017. The issuance of additional shares to Orion Holdings would dilute the holdings of the Company’s common stockholders and may negatively affect the value of the Company’s common stock. On August 3, 2018, pursuant to the Merger Agreement, the Company issued 80,084 shares of Class A common stock to Orion Holdings in connection with the net losses incurred for final resolution of the Chamblee Securities Class Action mentioned above. The net losses for the Chamblee Class Action include the $1.13 million contributed by the Company to the settlement but do not include the $13.63 million contributed by the Company’s insurers and certain attorneys’ fees that TerraForm Global, Inc. reimbursed to the Company pursuant to the insurance allocation arrangements entered into with the Company in 2017. As of the date hereof, the Company is unable to predict the quantum of any net losses arising from any of the litigation brought by the First Wind Sellers, Mr. Perez or Mr. Domenech described above or the number of additional shares, if any, that may be required to be issued to Orion Holdings pursuant to the terms of the Merger Agreement in connection with any final resolution of such matters.

Related Parties

Related Parties	6 Months Ended
	Jun. 30, 2018
Related Party Transactions [Abstract]
Related Parties	RELATED PARTIES As discussed in Note 1. Nature of Operations and Basis of Presentation , prior to the consummation of the Merger, TerraForm Power was a controlled affiliate of SunEdison, Inc. As a result of the consummation of the Merger on October 16, 2017, a change of control of TerraForm Power occurred, and Orion Holdings, which is an affiliate of Brookfield, held 51% of the voting securities of TerraForm Power immediately following the Merger consummation. As a result of the Merger closing, TerraForm Power is no longer a controlled affiliate of SunEdison, Inc. and is now a controlled affiliate of Brookfield. Further, on June 11, 2018, Orion Holdings and BEP collectively purchased in a private placement a total of 60,975,609 shares of TerraForm Power’s Class A common stock for a price per share of $10.66 , representing total consideration of approximately $650.0 million . As a result of this private placement, affiliates of Brookfield now hold approximately 65% of TerraForm Power’s Class A common stock. At or prior to the effective time of the Merger, the Company and Orion Holdings (or one of its affiliates), among other parties, entered into a suite of agreements providing for sponsorship arrangements. These include the agreements discussed below, as well as a governance agreement that established certain rights and obligations of the Company and controlled affiliates of Brookfield that own voting securities of the Company relating to the governance of the Company and a registration rights agreement that governs Orion Holdings’ and the Company’s rights and obligations with respect to the registration for resale of all or a part of the Class A shares that Orion Holdings now holds following the Merger. In connection with the private placement of shares on June 11, 2018 discussed above, Orion Holdings, BEP and TerraForm Power entered into a joinder to the registration rights agreement and governance agreement entered into in connection with the Merger, which added BEP as a party to each respective agreement. As discussed in Note 14. Commitments and Contingencies , as part of the Merger, the Company also agreed to issue shares of Class A common stock to Orion Holdings in connection with the final resolution of certain litigation matters described above. Brookfield Master Services Agreement In connection with the consummation of the Merger, the Company entered into a master services agreement (the “Brookfield MSA”) with Brookfield and certain affiliates of Brookfield (collectively, the “MSA Providers”) pursuant to which the MSA Providers provide certain management and administrative services to the Company, including the provision of strategic and investment management services. As consideration for the services provided or arranged for by Brookfield and certain of its affiliates pursuant to this agreement, the Company pays a base management fee on a quarterly basis, paid in arrears. Pursuant to the Brookfield MSA, the Company recorded $3.7 million and $6.9 million of charges within general and administrative expenses - affiliate in the unaudited condensed consolidated statements of operations for the three and six months ended June 30, 2018 , respectively. Relationship Agreement In connection with the consummation of the Merger, the Company entered into a relationship agreement (the “Relationship Agreement”) with Brookfield, which governs certain aspects of the relationship between Brookfield and the Company. Pursuant to the Relationship Agreement, Brookfield agrees that the Company will serve as the primary vehicle through which Brookfield and certain of its affiliates will own operating wind and solar assets in North America and Western Europe and that Brookfield will provide, subject to certain terms and conditions, the Company with a right of first offer on certain operating wind and solar assets that are located in such countries and developed by persons sponsored by or under the control of Brookfield. The Company did not acquire any renewable energy facilities from Brookfield during the six months ended June 30, 2018 . New Terra LLC Agreement SunEdison transferred all of the outstanding IDRs of Terra LLC held by SunEdison or certain of its affiliates to Brookfield IDR Holder at the effective time of the Merger, and the Company and Brookfield IDR Holder entered into an amended and restated limited liability company agreement of Terra LLC (the “New Terra LLC Agreement”). The New Terra LLC Agreement, among other things, reset the IDR thresholds of Terra LLC to establish a first distribution threshold of $0.93 per share of Class A common stock and a second distribution threshold of $1.05 per share of Class A common stock. There were no payments of IDRs made by the Company pursuant to the New Terra LLC Agreement during the six months ended June 30, 2018 , and there were no payments of IDRs made by the Company during the six months ended June 30, 2017 pursuant to the Terra LLC agreement existing as of that time. Lease In May 2018, in connection with the relocation of the Company’s corporate headquarters to New York City, the Company entered into a lease for office space and related arrangements with affiliates of Brookfield for a ten -year term. Due from affiliate The $1.5 million and $4.4 million due from affiliate amounts reported in the condensed consolidated balance sheets as of June 30, 2018 and December 31, 2017, respectively, each represents a receivable from TerraForm Global, Inc. as a result of payments made by the Company on its behalf regarding rent for its shared former corporate headquarters, compensation for certain employees that provided services to both companies and certain information technology services, of which $3.5 million of the 2017 year-end receivable was received in the first half of 2018. There was no right of set-off with respect to these receivables from TerraForm Global, Inc. and the payables to the other Brookfield affiliates described below, and thus these amounts were separately reported in due from affiliate in the unaudited condensed consolidated balance sheet at the respective periods. In April of 2018, the Company received $3.7 million from Brookfield and certain of its affiliates for the settlement of claims relating to certain transactions under Section 16(b) of the Exchange Act. The Company recognized the net proceeds of $3.0 million as a capital contribution from a stockholder and recorded it as an increase to additional paid-in capital, which is reflected within the other line in the condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018. Due to affiliates The $9.2 million due to affiliates amount reported in the unaudited condensed consolidated balance sheet as of June 30, 2018 primarily represents a $3.7 million payable to an affiliate of Brookfield for the Brookfield MSA base management fee for the second quarter of 2018, $3.7 million of acquisition-related costs payable to an affiliate of Brookfield for services paid on behalf of the Company, $ 1.1 million payable for leasehold improvements associated with its new corporate headquarters, $0.1 million of accrued interest that was payable to a Brookfield affiliate under the Sponsor Line, and $0.6 million payable to other affiliates of Brookfield for other services received. As of December 31, 2017, the $4.0 million due to affiliates amount represented a $3.4 million payable for the Brookfield MSA quarterly base management fee and $0.6 million of accrued standby fee interest that was payable to a Brookfield affiliate under the Sponsor Line. These 2017 year-end payables were paid in the first half of 2018, as well as $3.2 million representing the management fee for the first quarter of 2018, and $0.6 million of additional standby fee interest incurred in the first half of the year. In connection with the Bank Guarantee discussed in Note 14. Commitments and Contingencies , Brookfield provided credit support to the Company, and the Company agreed to pay a fee to Brookfield equal to 50% of the savings realized by the Company as a result of Brookfield’s provision of credit support, which amounted to $2.9 million and was paid in the second quarter of 2018. Historical SunEdison Services As discussed above, the Company was a controlled affiliate of SunEdison, Inc. during the six months ended June 30, 2017 and certain services were provided by SunEdison during that period. Cost of operations - affiliate was $3.4 million and $9.0 million for the three and six months ended June 30, 2017, respectively, which represented costs incurred for O&M and asset management services that were provided to the Company by SunEdison pursuant to contractual agreements and certain project-level transition services agreements. General and administrative expenses - affiliate was $3.3 million and $4.7 million for the three and six months ended June 30, 2017, respectively, which consisted of $0.9 million and $1.9 million of stock-based compensation expense for the respective periods that was allocated to the Company regarding equity awards in the stock of SunEdison, Inc. and TerraForm Global, Inc. (a controlled affiliate of SunEdison, Inc. at that time) that were awarded to the Company’s employees and $2.4 million and $2.8 million of costs incurred for certain management and administrative services that were provided by SunEdison during the respective periods. During the first quarter of 2017, the Company received $7.0 million from SunEdison in satisfaction of outstanding claims made under engineering, procurement and construction contracts (“EPC”), of which $4.8 million related to the Company’s renewable energy facility located in Chile and compensated the relevant project company as the facility’s performance during the warranty period was below that guaranteed by an affiliate of SunEdison under the applicable EPC contract.

Segment Reporting

Segment Reporting	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Segment Reporting	SEGMENT REPORTING Following the acquisition of Saeta (see Note 4. Acquisitions and Dispositions ), the Company’s management performed a review of its segment reporting structure and determined that the Company has three reportable segments: Solar, Wind, and Regulated Solar and Wind. These segments, which comprise the Company’s entire portfolio of renewable energy facility assets, have been determined based on the management approach. The management approach designates the internal reporting used by management for making decisions and assessing performance as the source of the reportable segments. An operating segment is defined as a component of an enterprise that engages in business activities from which it may earn revenues and incur expenses, and that has discrete financial information that is regularly reviewed by the chief operating decision maker in deciding how to allocate resources. Portugal Wind, Uruguay Wind, and the Regulated Spanish Solar and Wind segments are new operating segments that were added during the second quarter of 2018, and include all of Saeta’s operations. The Company’s operating segments now consist of Distributed Generation, North America Utility and International Utility that are aggregated into the Solar reportable segment, Northeast Wind, Central Wind, Hawaii Wind, Portugal Wind and Uruguay Wind operating segments that are aggregated into the Wind reportable segment, and the Regulated Spanish Solar and Wind operating segments that are aggregated within the Regulated Solar and Wind reportable segment. The operating segments have been aggregated as they have similar economic characteristics and meet all of the aggregation criteria. Corporate expenses include general and administrative expenses, acquisition costs, interest expense on corporate-level indebtedness, stock-based compensation and depreciation, accretion and amortization expense. All net operating revenues for the three and six months ended June 30, 2018 and 2017 were earned by the Company’s reportable segments from external customers in the United States (including Puerto Rico), Canada, Spain, Portugal, the United Kingdom, Uruguay and Chile. The following table reflects summarized financial information concerning the Company’s reportable segments for the three and six months ended June 30, 2018 and 2017 : Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 (In thousands) Solar Wind Regulated Solar and Wind Corporate Total Solar Wind Corporate Total Operating revenues, net $ 83,321 $ 75,281 $ 21,286 $ — $ 179,888 $ 101,485 $ 68,882 $ — $ 170,367 Depreciation, accretion and amortization expense 27,141 35,269 7,194 390 69,994 27,900 34,604 718 63,222 Impairment of renewable energy facilities — — — — — 1,429 1,429 — — 1,429 Other operating costs and expenses 14,467 32,718 5,041 30,369 82,595 16,487 24,781 38,901 80,169 Interest expense (income), net 15,734 11,246 (4,753 ) 28,665 50,892 19,942 21,330 26,933 68,205 Gain on sale of renewable energy facilities — — — — — (37,116 ) — — (37,116 ) Other non-operating (income) expenses, net (2,558 ) 32 110 2,001 (415 ) (872 ) 75 (2,634 ) (3,431 ) Income tax expense (benefit) 1 — 364 2,174 1,896 4,434 — — (588 ) (588 ) Net income (loss) $ 28,537 $ (4,348 ) $ 11,520 $ (63,321 ) $ (27,612 ) $ 73,715 $ (11,908 ) $ (63,330 ) $ (1,523 ) ——— (1) Income tax expense (benefit) is not allocated to the Company’s segments, except for certain foreign jurisdictions. Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 (In thousands) Solar Wind Regulated Solar and Wind Corporate Total Solar Wind Corporate Total Operating revenues, net $ 143,044 $ 143,105 $ 21,286 $ — $ 307,435 $ 167,486 $ 154,016 $ — $ 321,502 Depreciation, accretion and amortization expense 54,742 72,934 7,194 714 135,584 54,675 68,055 1,479 124,209 Impairment of renewable energy facilities 15,240 — — — 15,240 1,429 — — 1,429 Other operating costs and expenses 28,683 58,532 5,041 59,105 151,361 30,395 49,942 77,912 158,249 Interest expense (income), net 30,256 22,015 (4,753 ) 56,928 104,446 39,523 42,229 54,765 136,517 Gain on sale of renewable energy facilities — — — — — (37,116 ) — — (37,116 ) Other non-operating (income) expenses, net (2,558 ) 885 110 2,888 1,325 (914 ) 623 (2,193 ) (2,484 ) Income tax (benefit) expense 1 — 364 2,174 866 3,404 — — (1,157 ) (1,157 ) Net income (loss) $ 16,681 $ (11,625 ) $ 11,520 $ (120,501 ) $ (103,925 ) $ 79,494 $ (6,833 ) $ (130,806 ) $ (58,145 ) Balance Sheet Total assets 2 $ 2,823,676 $ 4,250,855 $ 2,458,868 $ 167,426 $ 9,700,825 $ 2,897,036 $ 3,400,858 $ 89,127 $ 6,387,021 ——— (1) Income tax expense (benefit) is not allocated to the Company’s segments, except for certain foreign jurisdictions. (2) Represents total assets as of June 30, 2018 and December 31, 2017 , respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income	The following tables present the changes in each component of accumulated other comprehensive income (loss), net of tax: (In thousands) Foreign Currency Translation Adjustments Hedging Activities 1 Accumulated Other Comprehensive Income Balance as of December 31, 2016 $ (22,133 ) $ 45,045 $ 22,912 Net unrealized gain arising during the period (net of zero and $4,480 tax expense, respectively) 5,601 10,622 16,223 Reclassification of net realized loss (gain) into earnings (net of tax benefit of $8,858 and tax expense of $406) 14,741 (621 ) 14,120 Other comprehensive income 20,342 10,001 30,343 Accumulated other comprehensive (loss) income (1,791 ) 55,046 53,255 Less: Other comprehensive (loss) income attributable to non-controlling interests (717 ) 11,839 11,122 Balance as of June 30, 2017 $ (1,074 ) $ 43,207 $ 42,133 (In thousands) Foreign Currency Translation Adjustments Hedging Activities 1 Accumulated Other Comprehensive Income Balance as of December 31, 2017 $ (13,412 ) $ 61,430 $ 48,018 Cumulative-effect adjustment net of tax expense of $1,579 2) — (4,164 ) (4,164 ) Other comprehensive loss: Net unrealized (loss) gain arising during the period (net of zero tax impact) (8,675 ) 1,907 (6,768 ) Reclassification of net realized gain into earnings (net of zero tax impact) — (923 ) (923 ) Other comprehensive loss (8,675 ) 984 (7,691 ) Accumulated other comprehensive (loss) income (22,087 ) 58,250 36,163 Less: Other comprehensive loss attributable to non-controlling interests — (1,237 ) (1,237 ) Balance as of June 30, 2018 $ (22,087 ) $ 59,487 $ 37,400 ——— (1) See Note 10 . Derivatives for further breakout of hedging gains and losses between interest rate swaps and commodity contracts. (2) See Note 2. Summary of Significant Accounting Policies for discussion regarding the Company’s adoption of ASU No. 2017-12 as of January 1, 2018.

Redeemable Non-controlling Inte

Redeemable Non-controlling Interests	6 Months Ended
	Jun. 30, 2018
Noncontrolling Interest [Abstract]
Redeemable Non-controlling Interests	REDEEMABLE NON-CONTROLLING INTERESTS During the second quarter of 2018, the Company discovered certain errors in its unaudited consolidated condensed financial statements for the periods ended March 31, 2018 and 2017, September 30, 2017, and June 30, 2017, and in its annual audited consolidated financial statements for the years ended December 31, 2017, 2016 and 2015. These errors relate to the Company’s accounting for certain intercompany transactions with non-wholly owned controlled subsidiaries and resulted in an overstatement of the allocation of net income attributable to the redeemable non-controlling interests with a corresponding understatement of the allocation of net income attributable to Class A common stockholders and non-controlling interests. The Company’s management assessed the impact of these adjustments and concluded the impact on the prior period financial statements was immaterial to each of the affected reporting periods and therefore amendment of previously filed reports was not required. However, the correction of the cumulative amount of the prior period errors would have been material to the current year consolidated financial statements and therefore, the Company corrected these errors in the prior periods included herein. These errors occurred between July 1, 2015, and March 31, 2018, therefore, there is no cumulative effect on the Company’s consolidated financial statements as of January 1, 2015. The correction had no impact on the previously reported amounts of consolidated cash flows from operating, investing or financing activities. The tables below summarize the effect of the corrections of the previously reported consolidated financial statement line items: Condensed Consolidated Balance Sheet March 31, 2018 (In thousands) As Previously Reported Adjustment Revised Deferred income taxes $ 16,839 $ 6,282 $ 23,121 Total liabilities 3,928,671 6,282 3,934,953 Redeemable non-controlling interests 50,760 (23,189 ) 27,571 Additional paid-in capital 1,841,692 5,919 1,847,611 Accumulated deficit (290,818 ) 10,988 (279,830 ) Total TerraForm Power, Inc. stockholders’ equity 1,576,008 16,907 1,592,915 Total stockholders’ equity 2,279,350 16,907 2,296,257 Consolidated Balance Sheet December 31, 2017 (In thousands) As Previously Reported Adjustment Revised Deferred income taxes $ 18,636 $ 6,336 $ 24,972 Total liabilities 3,958,313 6,336 3,964,649 Redeemable non-controlling interests 58,340 (23,680 ) 34,660 Additional paid-in capital 1,866,206 5,919 1,872,125 Accumulated deficit (398,629 ) 11,425 (387,204 ) Total TerraForm Power, Inc. stockholders’ equity 1,510,369 17,344 1,527,713 Total stockholders’ equity 2,370,368 17,344 2,387,712 Consolidated Balance Sheet December 31, 2016 (In thousands) As Previously Reported Adjustment Revised Deferred income taxes $ 27,723 $ 2,897 $ 30,620 Total liabilities 4,807,499 2,897 4,810,396 Redeemable non-controlling interests 180,367 (14,392 ) 165,975 Accumulated deficit (234,440 ) 7,390 (227,050 ) Total TerraForm Power, Inc. stockholders’ equity 1,252,957 7,390 1,260,347 Non-controlling interests 1,465,042 4,105 1,469,147 Total stockholders’ equity 2,717,999 11,495 2,729,494 Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) Three Months Ended March 31, 2018 Three Months Ended March 31, 2017 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax benefit $ (976 ) $ (54 ) $ (1,030 ) $ (918 ) $ 349 $ (569 ) Net loss (76,367 ) 54 (76,313 ) (56,273 ) (349 ) (56,622 ) Net (loss) income attributable to redeemable non-controlling interests (2,513 ) 491 (2,022 ) 835 (1,828 ) (993 ) Net (loss) income attributable to non-controlling interests (157,087 ) — (157,087 ) (25,339 ) 507 (24,832 ) Net income (loss) attributable to Class A common stockholders 83,233 (437 ) 82,796 (31,769 ) 972 (30,797 ) Earnings (loss) per share of Class A common stock - Basic and diluted 0.56 — 0.56 (0.37 ) 0.01 (0.36 ) Total comprehensive loss (91,104 ) 54 (91,050 ) (39,925 ) (349 ) (40,274 ) Comprehensive loss attributable to non-controlling interests (160,843 ) 491 (160,352 ) (17,614 ) (1,321 ) (18,935 ) Comprehensive income (loss) attributable to Class A common stockholders 69,739 (437 ) 69,302 (22,311 ) 972 (21,339 ) Consolidated Statements of Operations and Comprehensive Loss Three Months Ended December 31, 2017 Twelve Months Ended December 31, 2017 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax benefit $ (18,098 ) $ 713 $ (17,385 ) $ (23,080 ) $ 3,439 $ (19,641 ) Net loss (141,091 ) (713 ) (141,804 ) (232,864 ) (3,439 ) (236,303 ) Net loss excluding pre-acquisition net loss of renewable energy facilities acquired from SunEdison (141,091 ) (713 ) (141,804 ) (232,864 ) (3,439 ) (236,303 ) Net (loss) income attributable to redeemable non-controlling interests (7,278 ) (1,390 ) (8,668 ) 10,884 (9,288 ) 1,596 Net (loss) income attributable to non-controlling interests (20,514 ) 41 (20,473 ) (79,559 ) 1,814 (77,745 ) Net loss attributable to Class A common stockholders (113,299 ) 636 (112,663 ) (164,189 ) 4,035 (160,154 ) Loss per share of Class A common stock - Basic and diluted (0.82 ) — (0.82 ) (1.65 ) 0.04 (1.61 ) Total comprehensive loss (154,995 ) (713 ) (155,708 ) (192,458 ) (3,439 ) (195,897 ) Comprehensive loss attributable to non-controlling interests (33,023 ) (1,349 ) (34,372 ) (54,018 ) (7,474 ) (61,492 ) Comprehensive loss attributable to Class A common stockholders (121,972 ) 636 (121,336 ) (138,440 ) 4,035 (134,405 ) Condensed Consolidated Statements of Operations and Comprehensive Loss Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax benefit $ (2,633 ) $ 1,534 $ (1,099 ) $ (4,982 ) $ 2,726 $ (2,256 ) Net loss (34,820 ) (1,534 ) (36,354 ) (91,773 ) (2,726 ) (94,499 ) Net income attributable to redeemable non-controlling interests 6,803 (1,908 ) 4,895 18,162 (7,898 ) 10,264 Net loss attributable to non-controlling interests (15,077 ) 128 (14,949 ) (59,045 ) 1,773 (57,272 ) Net loss attributable to Class A common stockholders (26,546 ) 246 (26,300 ) (50,890 ) 3,399 (47,491 ) Loss per share of Class A common stock - Basic and diluted (0.31 ) — (0.31 ) (0.62 ) 0.03 (0.59 ) Total comprehensive loss (10,853 ) (1,534 ) (12,387 ) (37,463 ) (2,726 ) (40,189 ) Comprehensive income (loss) attributable to non-controlling interests 492 (1,780 ) (1,288 ) (20,995 ) (6,125 ) (27,120 ) Comprehensive loss attributable to Class A common stockholders (11,345 ) 246 (11,099 ) (16,468 ) 3,399 (13,069 ) Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) Three Months Ended June 30, 2017 Six Months Ended June 30, 2017 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax benefit $ (1,431 ) $ 843 $ (588 ) $ (2,349 ) $ 1,192 $ (1,157 ) Net loss (680 ) (843 ) (1,523 ) (56,953 ) (1,192 ) (58,145 ) Net income attributable to redeemable non-controlling interests 10,524 (4,162 ) 6,362 11,359 (5,990 ) 5,369 Net loss attributable to non-controlling interests (18,629 ) 1,138 (17,491 ) (43,968 ) 1,645 (42,323 ) Net income (loss) attributable to Class A common stockholders 7,425 2,181 9,606 (24,344 ) 3,153 (21,191 ) Earnings (loss) per share of Class A common stock - Basic and diluted 0.06 0.02 0.08 (0.31 ) 0.03 (0.28 ) Total comprehensive income (loss) 13,315 (843 ) 12,472 (26,610 ) (1,192 ) (27,802 ) Comprehensive loss attributable to non-controlling interests (3,873 ) (3,024 ) (6,897 ) (21,487 ) (4,345 ) (25,832 ) Comprehensive income (loss) attributable to Class A common stockholders 17,188 2,181 19,369 (5,123 ) 3,153 (1,970 ) Consolidated Statements of Operations and Comprehensive (Loss) Income Twelve Months Ended December 31, 2015 Twelve Months Ended December 31, 2016 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax (benefit) expense $ (13,241 ) $ 657 $ (12,584 ) $ 494 $ 2,240 $ 2,734 Net loss (208,135 ) (657 ) (208,792 ) (241,507 ) (2,240 ) (243,747 ) Net loss subsequent to IPO and excluding pre-acquisition net loss of renewable energy facilities acquired from SunEdison (209,745 ) (657 ) (210,402 ) (241,507 ) (2,240 ) (243,747 ) Net income attributable to redeemable non-controlling interests 8,512 (2,509 ) 6,003 18,365 (11,883 ) 6,482 Net loss attributable to non-controlling interest (138,371 ) 798 (137,573 ) (130,025 ) 3,307 (126,718 ) Net loss attributable to Class A common stockholders (79,886 ) 1,054 (78,832 ) (129,847 ) 6,336 (123,511 ) Loss per share of Class A common stock - Basic and diluted (1.25 ) 0.01 (1.24 ) (1.47 ) 0.07 (1.40 ) Total comprehensive loss (195,005 ) (657 ) (195,662 ) (240,665 ) (2,240 ) (242,905 ) Comprehensive loss subsequent to IPO and excluding pre-acquisition comprehensive income (loss) of renewable energy facilities acquired from SunEdison (236,631 ) (657 ) (237,288 ) (240,665 ) (2,240 ) (242,905 ) Comprehensive loss attributable to non-controlling interests (141,266 ) (1,711 ) (142,977 ) (110,830 ) (8,576 ) (119,406 ) Comprehensive loss attributable to Class A common stockholders (95,365 ) 1,054 (94,311 ) (129,835 ) 6,336 (123,499 ) The following table presents the activity of the redeemable non-controlling interests balance for the six months ended June 30, 2018: (In thousands) Redeemable Non-controlling Interests Balance as of December 31, 2017 $ 34,660 Cumulative-effect adjustment 1 (4,485 ) Redeemable non-controlling interests acquired in business combination 2 55,117 Distributions (1,118 ) Net loss 2,658 Foreign exchange differences (283 ) Balance as of June 30, 2018 $ 86,549 ——— (1) See discussion in Note 2. Summary of Significant Accounting Policies regarding the Company’s adoption of ASU No. 2014-09 and ASU No. 2016-08 as of January 1, 2018. (2) See Note 4. Acquisitions and Dispositions .

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Acquisition of Remaining Non-Controlling Interest in Saeta On July 2, 2018, the Company completed a statutory squeeze out procedure under Spanish law to procure the remaining approximately 4.72% of the shares of Saeta, which became a wholly-owned subsidiary as of that date. Share Repurchase Program On July 31, 2018, the Board of Directors of the Company authorized a program to repurchase up to 5% of the Company’s Class A common stock outstanding as of July 31, 2018, through July 31, 2019. The timing and the amount of any repurchases of common stock will be determined by the Company’s management based on its evaluation of market conditions and other factors. Repurchases of common stock may be made under a Rule 10b5-1 plan, which would permit common stock to be repurchased when the Company might otherwise be precluded from doing so under insider trading laws, open market purchases, privately-negotiated transactions, block purchases or otherwise in accordance with applicable federal securities laws, including Rule 10b-18 of the Exchange Act of 1934. The program may be suspended or discontinued at any time and does not obligate the Company to purchase any minimum number of shares. Any repurchased common stock will be held by the Company as treasury shares. The Company expects to fund any repurchases from available liquidity. Issuance of Shares upon Final Resolution of Chamblee Class Action On August 3, 2018, pursuant to the Merger Agreement, the Company issued 80,084 shares of Class A common stock to Orion Holdings in connection with the net losses incurred as a result of the final resolution of the Chamblee Class Action. The net losses for the Chamblee Class Action include the $1.13 million contributed by the Company to the settlement but do not include the $13.63 million contributed by the Company’s insurers and certain attorneys’ fees that TerraForm Global, Inc. reimbursed to the Company pursuant to the insurance allocation arrangements entered into with the Company in 2017. Third Quarter Dividends On August 13, 2018, the Board of Directors of the Company declared a third-quarter 2018 dividend with respect to its Class A common stock of $0.19 per share. The dividend is payable on September 15, 2018 to shareholders of record as of September 1, 2018. Long-Term Service Agreements for Wind Fleet On August 10, 2018, the Company executed an 11 -year Framework Agreement with General Electric (“GE”) that, among other things, provides for the roll out, subject to receipt of third party consents, of project level, long-term service agreements (collectively, the “LTSA”) for turbine operations and maintenance as well as other balance of plant services across the Company’s 1.6 GW North American wind fleet.

Nature of Operations and Basi28

Nature of Operations and Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the results of wholly-owned and partially-owned subsidiaries in which the Company has a controlling interest with all significant intercompany accounts and transactions eliminated and have been prepared in accordance with the SEC regulations for interim financial information. Accordingly, they do not include all of the information and notes required by accounting principles generally accepted in the United States of America (“U.S. GAAP”) for complete financial statements. The financial statements should be read in conjunction with the accounting policies and other disclosures as set forth in the notes to the Company’s annual financial statements for the year ended December 31, 2017, filed with the SEC on Form 10-K on March 7, 2018. Interim results are not necessarily indicative of results for a full year.
Use of Estimates	Use of Estimates In preparing the unaudited condensed consolidated financial statements, the Company used estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the financial statements. Such estimates also affect the reported amounts of revenues, expenses and cash flows during the reporting period. To the extent there are material differences between the estimates and actual results, the Company’s future results of operations would be affected.
Recently Adopted Accounting Standards - Guidance Adopted in 2018 and Recently Issued Accounting Standards Not Yet Adopted	Recently Adopted Accounting Standards - Guidance Adopted in 2018 In May 2014, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) , which replaces most existing revenue recognition guidance in U.S. GAAP and requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. Additionally, the new standard requires an entity to disclose further quantitative and qualitative information regarding the nature and amount of revenues arising from contracts with customers, as well as other information about the significant judgments and estimates used in recognizing revenues from contracts with customers. In March 2016, the FASB issued ASU No. 2016-08, Revenue from Contracts with Customers (Topic 606), Principal versus Agent Considerations (Reporting Revenue Gross versus Net) , which clarifies how to apply the implementation guidance on principal versus agent considerations related to the sale of goods or services to a customer as updated by ASU No. 2014-09. The Company adopted these standards as of January 1, 2018, which it collectively refers to as “Topic 606.” The Company analyzed the impact of Topic 606 on its revenue contracts which primarily include bundled energy and incentive sales through power purchase agreements (“PPAs”), individual renewable energy certificate (“REC”) sales, and upfront sales of federal & state incentive benefits recorded as deferred revenue and accreted into revenue. The Company elected to apply a modified retrospective approach with a cumulative-effect adjustment to accumulated deficit recognized as of January 1, 2018 for changes to revenue recognition resulting from Topic 606 adoption as described below. The Company adopted Topic 606 for all revenue contracts in-scope that had future performance obligations at January 1, 2018, and elected to use the contract modification practical expedient for purposes of computing the cumulative transition adjustment. See Note 3. Revenue for additional disclosures required by the new guidance. The Company accounts for the majority of its PPAs as operating leases under Accounting Standards Codification (“ASC”) 840, Leases and recognizes rental income as revenue when the electricity is delivered. The Company elected not to early adopt ASC 842, Leases in fiscal 2018 and therefore these PPAs are currently being evaluated in anticipation of the new lease standard adoption in fiscal 2019. For PPAs under the scope of Topic 606 in fiscal 2018, the Company concluded that there were no material changes to revenue recognition patterns from existing accounting practice. See Note 3. Revenue for the new revenue recognition policy. The Company evaluated the impact of Topic 606 as it relates to the individual sale of RECs. In certain jurisdictions, there may be a lag between physical generation of the underlying energy and the transfer of RECs to the customer due to administrative processes imposed by state regulations. Under the Company’s previous accounting policy, revenue was recognized as the underlying electricity was generated if the sale had been contracted with the customer. Based on the framework in Topic 606, for a portion of the existing individual REC sale arrangements where the transfer of control to the customer is determined to occur upon the transfer of the RECs, the Company now recognizes revenue commensurate with the transfer of RECs to the customer as compared to the generation of the underlying energy under the previous accounting policy. Revenue recognition practices for the remainder of existing individual REC sale arrangements remain the same; that is, revenue is recognized based on the underlying generation of energy because the contracted RECs are produced from a designated facility and control of the RECs transfers to the customer upon generation of the underlying energy. The adoption of Topic 606, as it relates to the individual sale of RECs, resulted in an increase in accumulated deficit on January 1, 2018 of $20.5 million , net of tax, and net of $0.3 million and $4.5 million that was allocated to non-controlling interests and redeemable non-controlling interests, respectively. The adjustments for accumulated deficit and non-controlling interests are reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018 and the redeemable non-controlling interests adjustment is reflected within cumulative-effect adjustment in the redeemable non-controlling interests roll-forward presented above. The impact on the Company’s results of operations for the first half of 2018 was minimal and is expected to be minimal for the remainder of 2018. The Company evaluated the impact of Topic 606 as it relates to the upfront sale of investment tax credits (“ITCs”) through its lease pass-through fund arrangements. The amounts allocated to the ITCs were initially recorded as deferred revenue in the consolidated balance sheet, and subsequently, one-fifth of the amounts allocated to the ITCs was recognized annually as incentives revenue in the consolidated statement of operations based on the anniversary of each solar energy system’s placed-in-service date. The Company concluded that revenue related to the sale of ITCs through its lease pass-through arrangements should be recognized at the point in time when the related solar energy systems are placed in service. Previously, the Company recognized this revenue evenly over the five -year ITC recapture period. The Company concluded that the likelihood of a recapture event related to these assessments is remote. The adoption of Topic 606, as it relates to the upfront sale of ITCs, resulted in a decrease in accumulated deficit on January 1, 2018 of $40.9 million , net of tax, which is reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018. The impact on the Company’s results of operations for the three and six months ended June 30, 2018 resulted in a decrease in non-cash deferred revenue recognition of $1.6 million and $5.1 million , respectively, and is expected to result in a decrease in non-cash deferred revenue recognition of approximately $11.2 million for the remaining six months of 2018. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230), Classification of Certain Cash Receipts and Cash Payments . The amendments of ASU No. 2016-15 were issued to address eight specific cash flow issues for which stakeholders have indicated to the FASB that a diversity in practice existed in how entities were presenting and classifying these items in the statement of cash flows. The issues addressed by ASU No. 2016-15 include but are not limited to the classification of debt prepayment and debt extinguishment costs, payments made for contingent consideration for a business combination, proceeds from the settlement of insurance proceeds, distributions received from equity method investees and separately identifiable cash flows and the application of the predominance principle. The adoption of ASU No. 2016-15 is required to be applied retrospectively. The Company adopted ASU No. 2016-15 as of January 1, 2018, which did not result in any material adjustments to the Company’s consolidated statements of cash flows. In October 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740), Intra-Entity Transfers of Assets Other Than Inventory . The amendments of ASU No. 2016-16 were issued to improve the accounting for the income tax consequences of intra-entity transfers of assets other than inventory. Previous GAAP prohibited the recognition of current and deferred income taxes for an intra-entity asset transfer until the asset had been sold to an outside party which resulted in diversity in practice and increased complexity within financial reporting. The amendments of ASU No. 2016-16 require an entity to recognize the income tax consequences of an intra-entity transfer of an asset other than inventory when the transfer occurs and do not require new disclosure requirements. The adoption of ASU No. 2016-16 should be applied on a modified retrospective basis through a cumulative-effect adjustment directly to retained earnings as of the beginning of the period of adoption. The adoption of ASU No. 2016-16 as of January 1, 2018 did not have an impact on the Company’s consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-01, Business Combinations (Topic 805), Clarifying the Definition of a Business . The amendment seeks to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or disposals) of assets or businesses. The definition of a business affects many areas of accounting including acquisitions, disposals, goodwill and consolidation. The amendments should be applied prospectively on or after the effective dates. Accordingly, the Company’s adoption of ASU No. 2017-01 as of January 1, 2018 did not have an impact on the Company’s historical financial statements. Based on the Company’s evaluation of the new guidance, the Company determined that the acquisition of the tendered shares of Saeta on June 12, 2018 qualifies to be accounted for as an acquisition of a business and the Company’s acquisition of a 6 megawatt (“MW”) portfolio of operating solar distributed generation assets located in California and New Jersey on June 29, 2018 should be accounted for as an acquisition of assets. See Note 4. Acquisitions and Dispositions for further discussion of the Saeta acquisition. In February 2017, the FASB issued ASU No. 2017-05, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20): Clarifying the Scope of Asset Derecognition Guidance and Accounting for Partial Sales of Nonfinancial Assets . This ASU is meant to clarify the scope of ASC Subtopic 610-20, Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets and to add guidance for partial sales of nonfinancial assets. ASU No. 2017-05 is to be applied using a full retrospective method or a modified retrospective method as outlined in the guidance. The adoption of ASU No. 2017-05 as of January 1, 2018 did not have an impact on the Company’s consolidated financial statements. In May 2017, the FASB issued ASU No. 2017-09, Compensation - Stock Compensation (Topic 718): Scope of Modification Accounting . The amendment clarifies when changes to the terms or conditions of a share-based payment award must be accounted for as a modification. The new guidance is expected to reduce diversity in practice and result in fewer changes to the terms of an award being accounted for as a modification. Changes to the terms or conditions of a share-based payment award that do not impact the fair value of the award, vesting conditions and the classification as an equity or liability instrument will not need to be assessed under modification accounting. The amendments in this update should be applied prospectively to an award modified on or after the adoption date. Accordingly, the Company’s adoption of ASU No. 2017-09 as of January 1, 2018 did not have an impact on the Company’s historical financial statements. The Company did not change the terms or conditions of any unvested share-based payment awards outstanding during the six months ended June 30, 2018 but will apply the impact of this standard in the future should it change the terms or conditions of any share-based payment awards. In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities . This ASU amends the hedge accounting model to enable entities to better portray the economics of their risk management activities in the financial statements and simplifies the application of hedge accounting in certain situations. ASU No. 2017-12 is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018, with early adoption permitted. ASU 2017-12 requires a modified retrospective transition method in which the Company recognizes the cumulative effect of the change on the opening balance of each affected component of equity as of the date of adoption. The Company adopted ASU 2017-12 on March 26, 2018 with the adoption impact reflected on a modified retrospective basis as of January 1, 2018, which resulted in the following primary changes: • The ineffective hedging portion of derivatives designated as hedging instruments is no longer required to be measured, recognized or reported. Alternatively, the entire change in the fair value of the designated hedging instrument is recorded in accumulated other comprehensive income (“AOCI”); • The Company will perform ongoing prospective and retrospective hedge effectiveness assessments qualitatively after performing the initial test of hedge effectiveness on a quantitative basis and only to the extent that an expectation of high effectiveness can be supported on a qualitative basis in subsequent periods; • For derivatives with periodic cash settlements and a non-zero fair value at hedge inception, the gains or losses recorded in AOCI in a qualifying cash flow hedging relationship are reclassified to earnings on a systematic and rational basis over the hedge term; and • For derivatives with components excluded from the assessment of hedge effectiveness, the gains or losses recorded in AOCI on such excluded components in a qualifying cash flow hedging relationship are reclassified to earnings on a systematic and rational basis over the hedge term. The adoption of ASU 2017-12 resulted in a cumulative-effect adjustment of $4.2 million , net of tax of $1.6 million , representing a decrease in accumulated deficit and AOCI, which is reflected within cumulative-effect adjustment in the unaudited condensed consolidated statement of stockholders’ equity for the six months ended June 30, 2018. In March 2018, the FASB issued ASU No. 2018-05, Income Taxes (Topic 740) – Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 . The ASU added seven paragraphs to ASC 740, Income Taxes , that contain SEC guidance related to the application of U.S. GAAP when preparing an initial accounting of the income tax effects of the Tax Act which, among other things, allows for a measurement period not to exceed one year for companies to finalize the provisional amounts recorded as of December 31, 2017. The ASU was effective upon issuance. See Note 9. Income Taxes for disclosures on the Company’s accounting for the Tax Act. Recently Issued Accounting Standards Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) , and in July 2018, the FASB issued ASU No. 2018-10, Codification Improvements to Topic 842, Leases, which primarily change the lessee’s accounting for operating leases by requiring recognition of lease right-of-use assets and lease liabilities. The Company expects to adopt the guidance on January 1, 2019. The issued guidance requires a modified retrospective transition approach, which requires entities to recognize and measure leases at the beginning of the earliest period presented. In January 2018, the FASB proposed amending the standard to give entities another option for transition. The proposed transition method would allow entities to initially apply the requirements of the standard in the period of adoption (January 1, 2019). The Company will assess this transition option if the FASB issues the revised standard. The Company expects to elect certain of the practical expedients permitted in the issued standard, including the expedient that permits the Company to retain its existing lease assessment and classification. In January 2018, the FASB issued additional guidance which provides another optional transition practical expedient that allows entities to not evaluate existing and expired land easements under the new guidance at adoption if they were not previously accounted for as leases. The Company is currently working through an adoption plan which includes the evaluation of lease contracts compared to the new standard. While the Company is currently evaluating the impact the new guidance will have on its financial position and results of operations, the Company expects to recognize lease liabilities and right of use assets. The extent of the increase to assets and liabilities associated with these amounts remains to be determined pending the Company’s review of its existing lease contracts which may contain embedded leases. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350), Simplifying the Test for Goodwill Impairment . The amendment simplifies the accounting for goodwill impairment by removing Step 2 of the current test, which requires calculation of a hypothetical purchase price allocation. Under the revised guidance, goodwill impairment will be measured as the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill (currently Step 1 of the two-step impairment test). Entities will continue to have the option to perform a qualitative assessment to determine if a quantitative impairment test is necessary. The standard is effective January 1, 2020, with early adoption permitted, and must be adopted on a prospective basis. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income to help entities address certain stranded income tax effects in AOCI resulting from the U.S. government’s enactment of the Tax Act on December 22, 2017. The amendment provides entities with an option to reclassify stranded tax effects within AOCI to retained earnings in each period in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act (or portion thereof) is recorded. The amendment also includes disclosure requirements regarding the issuer’s accounting policy for releasing income tax effects from AOCI. The optional guidance is effective for annual periods, and interim periods within those annual periods, beginning after December 15, 2018. Early adoption is permitted, and entities should apply the provisions of the amendment either in the period of adoption or retrospectively to each period (or periods) in which the effect of the change in the U.S. federal corporate income tax rate in the Tax Act is recognized. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In February 2018, the FASB issued ASU No. 2018-03, Technical Corrections and Improvements to Financial Instruments - Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities . This ASU amends and supersedes various paragraphs that contain SEC guidance in ASC 320, Investments - Debt Securities and ASC 980, Regulated Operations . ASU No. 2018-03 is effective for public business entities for fiscal years beginning after December 15, 2017 and interim periods within those fiscal years beginning after June 15, 2018. Public business entities with fiscal years beginning between December 15, 2017 and June 15, 2018 are not required to adopt these amendments until the interim period beginning after June 15, 2018. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements.
Earnings (Loss) Per Share	Basic (loss) earnings per share is computed by dividing net (loss) income attributable to Class A common stockholders by the number of weighted average ordinary shares outstanding during the period, which is the average of shares outstanding and assumed to be outstanding, and includes contingently issuable shares as of the date when the contingent condition has been met. Diluted (loss) earnings per share is computed by adjusting basic earnings (loss) per share for the impact of weighted average dilutive common equivalent shares outstanding during the period, unless the impact is anti-dilutive. Common equivalent shares include the incremental shares issuable for unvested restricted Class A common stock and contingently issuable shares in the period the contingency has been met, for the portion of the period prior to the resolution of such contingent condition.
Segment Reporting	Company has three reportable segments: Solar, Wind, and Regulated Solar and Wind. These segments, which comprise the Company’s entire portfolio of renewable energy facility assets, have been determined based on the management approach. The management approach designates the internal reporting used by management for making decisions and assessing performance as the source of the reportable segments. An operating segment is defined as a component of an enterprise that engages in business activities from which it may earn revenues and incur expenses, and that has discrete financial information that is regularly reviewed by the chief operating decision maker in deciding how to allocate resources. Portugal Wind, Uruguay Wind, and the Regulated Spanish Solar and Wind segments are new operating segments that were added during the second quarter of 2018, and include all of Saeta’s operations. The Company’s operating segments now consist of Distributed Generation, North America Utility and International Utility that are aggregated into the Solar reportable segment, Northeast Wind, Central Wind, Hawaii Wind, Portugal Wind and Uruguay Wind operating segments that are aggregated into the Wind reportable segment, and the Regulated Spanish Solar and Wind operating segments that are aggregated within the Regulated Solar and Wind reportable segment. The operating segments have been aggregated as they have similar economic characteristics and meet all of the aggregation criteria. Corporate expenses include general and administrative expenses, acquisition costs, interest expense on corporate-level indebtedness, stock-based compensation and depreciation, accretion and amortization expense. All net operating revenues for the three and six months ended June 30, 2018 and 2017 were earned by the Company’s reportable segments from external customers in the United States (including Puerto Rico), Canada, Spain, Portugal, the United Kingdom, Uruguay and Chile.

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Reconciliation of Cash and Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the unaudited condensed consolidated balance sheets to the total of the same such amounts shown in the unaudited condensed consolidated statement of cash flows for the six months ended June 30, 2018. (In thousands) June 30, December 31, Cash and cash equivalents $ 339,209 $ 128,087 Restricted cash - current 38,823 54,006 Restricted cash - non-current 138,053 42,694 Cash, cash equivalents and restricted cash shown in the unaudited condensed consolidated statement of cash flows $ 516,085 $ 224,787

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2018
Revenue from Contract with Customer [Abstract]
Schedule of Impact of Topic 606	Topic 606 Adoption Impact on Unaudited Condensed Consolidated Statements of Operations Three Months Ended June 30, 2018 As Reported Adjustments Amounts excluding Topic 606 Adoption (In thousands) Solar Wind Regulated Wind and Solar Total REC Sales ITC Sales PPA rental income $ 55,366 $ 50,899 — $ 106,265 $ — $ — $ 106,265 Commodity derivatives — 21,441 — 21,441 — — 21,441 PPA revenue 13,458 6,359 — 19,817 — — 19,817 Regulated solar and wind revenue — — 21,286 21,286 — — 21,286 Amortization of favorable and unfavorable rate revenue contracts, net (1,966 ) (7,784 ) — (9,750 ) — — (9,750 ) Energy revenue 66,858 70,915 21,286 159,059 — — 159,059 Incentive revenue 16,463 4,366 — 20,829 5,586 1,598 28,013 Operating revenues, net 83,321 75,281 21,286 179,888 5,586 1,598 187,072 Operating costs and expenses 152,589 — — 152,589 Operating income 27,299 5,586 1,598 34,483 Other expenses, net 50,477 — — 50,477 (Loss) income before income tax expense (23,178 ) 5,586 1,598 (15,994 ) Income tax expense 4,434 — — 4,434 Net loss $ (27,612 ) $ 5,586 $ 1,598 $ (20,428 ) Six Months Ended June 30, 2018 As Reported Adjustments Amounts excluding Topic 606 Adoption (In thousands) Solar Wind Regulated Wind and Solar Total REC Sales ITC Sales PPA rental income $ 92,134 $ 103,312 $ — $ 195,446 $ — $ — $ 195,446 Commodity derivatives — 32,448 — 32,448 — — 32,448 PPA revenue 19,965 13,051 — 33,016 — — 33,016 Regulated solar and wind revenue — — 21,286 21,286 — — 21,286 Amortization of favorable and unfavorable rate revenue contracts, net (3,943 ) (15,624 ) — (19,567 ) — — (19,567 ) Energy revenue 108,156 133,187 21,286 262,629 — — 262,629 Incentive revenue 34,888 9,918 — 44,806 3,026 5,116 52,948 Operating revenues, net 143,044 143,105 21,286 307,435 3,026 5,116 315,577 Operating costs and expenses 302,185 — — 302,185 Operating income 5,250 3,026 5,116 13,392 Other expenses, net 105,771 — — 105,771 Loss before income tax expense (100,521 ) 3,026 5,116 (92,379 ) Income tax expense 3,404 — — 3,404 Net (loss) income $ (103,925 ) $ 3,026 $ 5,116 $ (95,783 ) Topic 606 Adoption Impact on Unaudited Condensed Consolidated Balance Sheet As of June 30, 2018 As Reported Adjustments Amounts excluding Topic 606 Adoption (In thousands) REC Sales ITC Sales Accounts receivable, net $ 161,017 $ 28,301 $ — $ 189,318 Other current assets 451,523 — — 451,523 Total current assets 612,540 28,301 — 640,841 Non-current assets 9,088,285 — — 9,088,285 Total assets $ 9,700,825 $ 28,301 $ — $ 9,729,126 Deferred revenue $ 1,735 $ — $ 16,310 $ 18,045 Other current liabilities 684,516 — — 684,516 Total current liabilities 686,251 — 16,310 702,561 Deferred revenue, less current portion 12,780 — 19,471 32,251 Other non-current liabilities 6,028,547 — — 6,028,547 Total liabilities 6,727,578 — 35,781 6,763,359 Redeemable non-controlling interests and total stockholders’ equity 2,973,247 28,301 (35,781 ) 2,965,767 Total liabilities, redeemable non-controlling interests and stockholders’ equity $ 9,700,825 $ 28,301 $ — $ 9,729,126

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	6 Months Ended
	Jun. 30, 2018
Business Combinations [Abstract]
Business Acquisition, Pro Forma Information	The unaudited pro forma supplementary data presented in the table below gives effect to the Saeta acquisition, as if the transaction had occurred on January 1, 2017. The pro forma net loss includes interest expense related to incremental borrowings used to finance the transaction and adjustments to depreciation and amortization expense for the valuation of renewable energy facilities and intangible assets. The pro forma net loss for the six months ended June 30, 2018 excludes the impact of acquisition related costs disclosed below. The unaudited pro forma supplementary data is provided for informational purposes only and should not be construed to be indicative of the Company’s results of operations had the acquisition been consummated on the date assumed or of the Company’s results of operations for any future date. Six Months Ended June 30, (In thousands) 2018 2017 Total operating revenues, net $ 496,268 $ 491,812 Net loss (90,088 ) (57,713 )
Allocation of Acquisition-Date Fair Value of Assets, Liabilities and Non-controlling Interests	The preliminary allocation of the acquisition-date fair values of assets, liabilities and non-controlling interests pertaining to this business combination as of June 30, 2018, were as follows: (In thousands) Saeta Renewable energy facilities in service $ 1,988,993 Accounts receivable 90,555 Intangible assets 992,883 Goodwill 115,381 Other assets 44,190 Total assets acquired 3,232,002 Accounts payable, accrued expenses and other current liabilities 92,965 Long-term debt, including current portion 1,906,831 Deferred income taxes 174,080 Asset retirement obligations 11,454 Derivative liabilities 1 137,002 Other long-term liabilities 23,069 Total liabilities assumed 2,345,401 Redeemable non-controlling interests 2 55,117 Purchase price, net of cash and restricted cash acquired 3 $ 831,484 ——— (1) Derivative liabilities are included within other long-term liabilities in the unaudited condensed consolidated balance sheets. (2) The fair value of the non-controlling interest was determined using a market approach using a quoted price for the instrument. As discussed above, the Company acquired the remaining shares of Saeta pursuant to a statutory squeeze out procedure under Spanish law, which closed on July 2, 2018 . The quoted price for the purchase of the non-controlling interest is the best indicator of fair value and was supported by a discounted cash flow technique. (3) The Company acquired cash and cash equivalents of $187.2 million and restricted cash of $95.1 million as of the acquisition date.
Intangible Assets at Acquisition Date	The following table summarizes the estimated fair value and weighted average amortization period of acquired intangible assets as of the acquisition date for Saeta. The Company attributed intangible asset value to concessions and license agreements in-place from solar and wind facilities. These intangible assets are amortized on a straight-line basis over the estimated remaining useful life of the facility from the Company’s acquisition date. Saeta Fair Value (In thousands) Weighted Average Amortization Period (In years) 1 Intangible assets - concessions and licenses $992,883 17 years ——— (1) For purposes of this disclosure, the weighted average amortization period is determined based on a weighting of the individual intangible fair values against the total fair value for each major intangible asset and liability class.

Renewable Energy Facilities (Ta

Renewable Energy Facilities (Tables)	6 Months Ended
	Jun. 30, 2018
Property, Plant and Equipment [Abstract]
Renewable Energy Facilities	Renewable energy facilities, net consists of the following: (In thousands) June 30, December 31, Renewable energy facilities in service, at cost 1 $ 7,316,084 $ 5,378,462 Less: accumulated depreciation - renewable energy facilities (683,260 ) (578,474 ) Renewable energy facilities in service, net 6,632,824 4,799,988 Construction in progress - renewable energy facilities 2,102 1,937 Total renewable energy facilities, net $ 6,634,926 $ 4,801,925 ——— (1) The increase in renewable energy facilities is primarily due to the acquisition of Saeta. See Note 4. Acquisitions and Dispositions .

Intangible Assets, Net and Go33

Intangible Assets, Net and Goodwill (Tables)	6 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Gross Carrying Amount and Accumulated Amortization of Intangibles	The following table presents the gross carrying amount, accumulated amortization and net book value of intangibles as of June 30, 2018 : (In thousands, except weighted average amortization period) Weighted Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Book Value Concession and licensing contracts 1 17 years $ 990,497 $ (2,953 ) $ 987,544 Favorable rate revenue contracts 14 years 713,066 (120,975 ) 592,091 In-place value of market rate revenue contracts 18 years 527,779 (86,631 ) 441,148 Favorable rate land leases 17 years 15,800 (2,729 ) 13,071 Total intangible assets, net $ 2,247,142 $ (213,288 ) $ 2,033,854 Unfavorable rate revenue contracts 7 years $ 33,686 $ (17,181 ) $ 16,505 Unfavorable rate operations and maintenance contracts 1 year 5,000 (3,177 ) 1,823 Unfavorable rate land lease 15 years 1,000 (190 ) 810 Total intangible liabilities, net 2 $ 39,686 $ (20,548 ) $ 19,138 The following table presents the gross carrying amount, accumulated amortization and net book value of intangibles as of December 31, 2017 : (In thousands, except weighted average amortization period) Weighted Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Book Value Favorable rate revenue contracts 15 years $ 718,639 $ (102,543 ) $ 616,096 In-place value of market rate revenue contracts 19 years 521,323 (73,104 ) 448,219 Favorable rate land leases 17 years 15,800 (2,329 ) 13,471 Total intangible assets, net $ 1,255,762 $ (177,976 ) $ 1,077,786 Unfavorable rate revenue contracts 7 years $ 35,086 $ (16,030 ) $ 19,056 Unfavorable rate operations and maintenance contracts 2 years 5,000 (2,552 ) 2,448 Unfavorable rate land lease 15 years 1,000 (162 ) 838 Total intangible liabilities, net 2 $ 41,086 $ (18,744 ) $ 22,342 ——— (1) See Note. 4 Acquisitions and Dispositions for a discussion of the intangible assets related to Saeta. (2) The Company’s intangible liabilities are classified within other long-term liabilities in the unaudited condensed consolidated balance sheets.

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Carrying Amounts and Classification of Consolidated VIE's Assets and Liabilities	The carrying amounts and classification of the consolidated VIEs’ assets and liabilities included in the Company’s unaudited condensed consolidated balance sheets are as follows: (In thousands) June 30, December 31, Current assets $ 131,080 $ 142,403 Non-current assets 4,062,705 4,155,558 Total assets $ 4,193,785 $ 4,297,961 Current liabilities $ 99,330 $ 119,021 Non-current liabilities 1,072,324 975,839 Total liabilities $ 1,171,654 $ 1,094,860

Long-term Debt (Tables)

Long-term Debt (Tables)	6 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Schedule of Debt	Long-term debt, including affiliate amounts, consists of the following: (In thousands, except rates) June 30, December 31, Interest Type Interest Rate (%) 1 Financing Type Corporate-level long-term debt - affiliate: Sponsor Line 2 $ 86,000 $ — Variable 5.05 Revolving loan Corporate-level long-term debt 3 : Senior Notes due 2023 $ 500,000 $ 500,000 Fixed 4.25 Senior notes Senior Notes due 2025 300,000 300,000 Fixed 6.63 Senior notes Senior Notes due 2028 700,000 700,000 Fixed 5.00 Senior notes Revolver 4 451,362 60,000 Variable 4.93 Revolving loan Term Loan 5 348,250 350,000 Variable 3.98 Term debt Non-recourse long-term debt 6 : Permanent financing 3,499,216 1,616,729 Blended 7 4.92 8 Term debt / Senior notes Financing lease obligations 111,548 115,787 Imputed 5.60 8 Financing lease obligations Total principal due for long-term debt and financing lease obligations 5,996,376 3,642,516 4.93 8 Unamortized discount, net (17,462 ) (19,027 ) Deferred financing costs, net (17,798 ) (24,689 ) Less: current portion of long-term debt and financing lease obligations (458,177 ) (403,488 ) Long-term debt and financing lease obligations, less current portion $ 5,502,939 $ 3,195,312 ——— (1) As of June 30, 2018 . (2) On October 16, 2017, TerraForm Power, Inc. entered into a credit agreement with Brookfield and one of its affiliates as lenders that established a $500.0 million secured revolving credit facility (the “Sponsor Line”) and provides for the lenders to commit to make LIBOR loans to the Company during a period not to exceed three years from the effective date of the agreement (subject to acceleration for certain specified events). The Company may only use the Sponsor Line to fund all or a portion of certain funded acquisitions or growth capital expenditures. (3) Corporate-level debt represents debt issued by Terra Operating LLC and guaranteed by Terra LLC and certain subsidiaries of Terra Operating LLC other than non-recourse subsidiaries as defined in the relevant debt agreements (with the exception of certain unencumbered non-recourse subsidiaries). (4) On February 6, 2018, Terra Operating LLC elected to increase the total borrowing capacity of its $450.0 million senior secured revolving credit facility (the “Revolver”), available for revolving loans and letters of credit, to $600.0 million . The balance includes $9.4 million drawn on an approximately $147.0 million revolving credit facility obtained by Saeta, as well as other credit facilities of Saeta. (5) On May 11, 2018, the Company signed a repricing amendment whereby the interest rate on the Term Loan was reduced by 0.75% per annum. (6) Non-recourse debt represents debt issued by subsidiaries with no recourse to TerraForm Power, Terra LLC, Terra Operating LLC or guarantors of the Company’s corporate-level debt, other than limited or capped contingent support obligations, which in aggregate are not considered to be material to the Company’s business and financial condition. In connection with these financings and in the ordinary course of its business, TerraForm Power and its subsidiaries observe formalities and operating procedures to maintain each of their separate existence and can readily identify each of their separate assets and liabilities as separate and distinct from each other. As a result, these subsidiaries are legal entities that are separate and distinct from TerraForm Power, Terra LLC, Terra Operating LLC and the guarantors of the Company’s corporate-level debt. (7) Includes fixed rate debt and variable rate debt. As of June 30, 2018, 74% of this balance had a fixed interest rate and the remaining 26% of this balance had a variable interest rate. The Company entered into interest rate swap agreements to fix the interest rates of a majority of the variable rate permanent financing non-recourse debt (see Note 10 . Derivatives ). (8) Represents the weighted average interest rate as of June 30, 2018.
Aggregate Contractual Payments of Long-term Debt	The aggregate contractual principal payments of long-term debt due after June 30, 2018 , including financing lease obligations and excluding amortization of debt discounts, premiums and deferred financing costs, as stated in the financing agreements, are as follows: (In thousands) Remainder of 2018 2019 2020 2021 2022 Thereafter Total Maturities of long-term debt $ 120,727 $ 251,675 $ 254,507 $ 696,995 $ 746,954 $ 3,925,518 $ 5,996,376 ——— (1) Represents the contractual principal payment due dates for the Company’s long-term debt and does not reflect the reclassification of $199.7 million of long-term debt to current as a result of debt defaults under certain of the Company’s non-recourse financing arrangements.

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Components of Income Tax Provision	The income tax provision consisted of the following: Three Months Ended June 30, Six Months Ended June 30, (In thousands, except effective tax rate) 2018 2017 2018 2017 Loss before income tax expense (benefit) $ (23,178 ) $ (2,111 ) $ (100,521 ) $ (59,302 ) Income tax expense (benefit) 4,434 (588 ) 3,404 (1,157 ) Effective tax rate (19.1 )% 27.9 % (3.4 )% 2.0 %

Derivatives (Tables)

Derivatives (Tables)	6 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Fair Values of Derivative Instruments	As of June 30, 2018 and December 31, 2017 , fair values of the following derivative instruments were included in the balance sheet captions indicated below: Fair Value of Derivative Instruments Derivatives Designated as Hedging Instruments Derivatives Not Designated as Hedging Instruments (In thousands) Interest Rate Swaps Commodity Contracts Interest Rate Swaps Foreign Currency Contracts Commodity Contracts Gross Amounts of Assets/Liabilities Recognized Counterparty Netting Net Amounts in Consolidated Balance Sheet As of June 30, 2018 Prepaid expenses and other current assets $ 908 $ 1,200 $ — $ 46,822 $ 15,236 $ 64,166 $ (45,924 ) $ 18,242 Other assets 11,172 39,205 456 22,690 46,808 120,331 (456 ) 119,875 Total assets $ 12,080 $ 40,405 $ 456 $ 69,512 $ 62,044 $ 184,497 $ (46,380 ) $ 138,117 Accounts payable, accrued expenses and other current liabilities $ 600 $ — $ 35,345 $ 56,870 $ — $ 92,815 $ (45,924 ) $ 46,891 Other long-term liabilities 2,152 — 90,660 — — 92,812 (456 ) 92,356 Total liabilities $ 2,752 $ — $ 126,005 $ 56,870 $ — $ 185,627 $ (46,380 ) $ 139,247 As of December 31, 2017 Prepaid expenses and other current assets $ — $ 8,961 $ — $ 63 $ 12,609 $ 21,633 $ (63 ) $ 21,570 Other assets 4,686 71,307 — — 14,787 90,780 — 90,780 Total assets $ 4,686 $ 80,268 $ — $ 63 $ 27,396 $ 112,413 $ (63 ) $ 112,350 Accounts payable, accrued expenses and other current liabilities $ 2,490 $ — $ 197 $ 99 $ — $ 2,786 $ (63 ) $ 2,723 Other long-term liabilities 4,796 — 404 — — 5,200 — 5,200 Total liabilities $ 7,286 $ — $ 601 $ 99 $ — $ 7,986 $ (63 ) $ 7,923
Schedule of Notional Amounts for Derivative Instruments	As of June 30, 2018 and December 31, 2017 , notional amounts for derivative instruments consisted of the following: Notional Amount as of (In thousands) June 30, 2018 December 31, 2017 Derivatives designated as hedging instruments: Interest rate swaps (USD) 371,560 395,986 Interest rate swaps (CAD) 151,778 156,367 Commodity contracts (MWhs) 6,334 15,579 Derivatives not designated as hedging instruments: Interest rate swaps (USD) 13,132 13,520 Foreign currency contracts (CAD) — 9,875 Interest rate swaps (EUR) 1,065,137 — Foreign currency contracts (EUR) 3,395,200 — Commodity contracts (MWhs) 9,247 987
Gains and Losses on Derivatives Not Designated As Hedges	Gains and losses on derivatives not designated as hedging instruments for the three and six months ended June 30, 2018 and 2017 consisted of the following: Location of Loss (Gain) in the Statements of Operations Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2018 2017 2018 2017 Interest rate swaps Interest expense, net $ (7,763 ) $ 1,818 $ (7,989 ) $ 3,192 Foreign currency contracts (Gain) loss on foreign currency exchange, net (13,792 ) 347 (12,566 ) 560 Commodity contracts Operating revenues, net (17,084 ) (1,579 ) (17,494 ) (5,692 )
Gains and Losses Recognized Related to Interest Rate Swaps and Commodity Contracts Designated as Cash Flow Hedges	Gains and losses recognized related to interest rate swaps and commodity contracts designated as hedging instruments for the three and six months ended June 30, 2018 and 2017 consisted of the following: Three Months Ended June 30, Derivatives in Cash Flow Hedging Relationships Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, net of taxes 1 Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach 2 Location of Amount Reclassified from AOCI into Income (Gain) Loss Included in the Assessment of Effectiveness Reclassified from AOCI into Income 3 (Gain) Loss Excluded from the Assessment of Effectiveness that is Amortized through Earnings 2 (In thousands) 2018 2017 2018 2017 2018 2017 Interest rate swaps $ 2,645 $ (1,633 ) $ — $ — Interest expense, net $ 292 $ (217 ) $ — $ (322 ) Commodity contracts 11,623 (1,799 ) — — Operating revenues, net (731 ) (18 ) (347 ) 2,894 Total $ 14,268 $ (3,432 ) $ — $ — $ (439 ) $ (235 ) $ (347 ) $ 2,572 ———— (1) Net of tax benefit of zero and $0.5 million attributed to interest rate swaps during the three months ended June 30, 2018 and 2017, respectively. Net of tax benefit of zero and $3.7 million attributed to commodity contracts during the three months ended June 30, 2018 and 2017, respectively. (2) As a result of the adoption of ASU No. 2017-12 effective January 1, 2018 (see Note 2. Summary of Significant Accounting Policies ), certain gains and losses were excluded from the assessment of effectiveness that are being amortized through earnings for the three months ended June 30, 2018. No such amounts existed for the three months ended June 30, 2017 prior to the adoption of ASU No. 2017-12. (3) Net of tax benefit of zero and $1.7 million attributed to interest rate swaps during the three months ended June 30, 2018 and 2017, respectively. Net of tax expense of zero and $2.1 million attributed to commodity contracts during the three months ended June 30, 2018 and 2017, respectively. Six Months Ended June 30, Derivatives in Cash Flow Hedging Relationships Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, net of taxes 1 Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach 2 Location of Amount Reclassified from AOCI into Income (Gain) Loss Included in the Assessment of Effectiveness Reclassified from AOCI into Income 3 (Gain) Loss Excluded from the Assessment of Effectiveness that is Amortized through Earnings 2 (In thousands) 2018 2017 2018 2017 2018 2017 2018 2017 Interest rate swaps $ 10,520 $ (3,252 ) — $ — Interest expense, net $ 973 $ 2,644 $ — $ 491 Commodity contracts (7,479 ) 13,874 735 — Operating revenues, net (2,042 ) (3,265 ) (679 ) 3,083 Total $ 3,041 $ 10,622 $ 735 $ — $ (1,069 ) $ (621 ) $ (679 ) $ 3,574 ———— (1) Net of tax benefit of zero and $0.5 million attributed to interest rate swaps during the six months ended June 30, 2018 and 2017, respectively. Net of tax expense of zero and $2.1 million attributed to commodity contracts during the six months ended June 30, 2018 and 2017, respectively. (2) As a result of the adoption of ASU No. 2017-12 effective January 1, 2018 (see Note 2. Summary of Significant Accounting Policies ), certain gains and losses were excluded from the assessment of effectiveness that are being amortized through earnings for the six months ended June 30, 2018. No such amounts existed for the six months ended June 30, 2017 prior to the adoption of ASU No. 2017-12. (3) Net of tax benefit of zero and $1.7 million attributed to interest rate swaps during the six months ended June 30, 2018 and 2017, respectively. Net of tax expense of zero and $2.1 million attributed to commodity contracts during the six months ended June 30, 2018 and 2017, respectively.

Fair Value of Financial Instr38

Fair Value of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Financial Instruments Measured at Fair Value on a Recurring Basis	The following table summarizes the financial instruments measured at fair value on a recurring basis classified in the fair value hierarchy (Level 1, 2 or 3) based on the inputs used for valuation in the unaudited condensed consolidated balance sheets: (In thousands) As of June 30, 2018 As of December 31, 2017 Assets Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Interest rate swaps $ — $ 12,080 $ — $ 12,080 $ — $ 4,686 $ — $ 4,686 Commodity contracts — 20,590 81,859 102,449 — 27,396 80,268 107,664 Foreign currency contracts — 23,588 — 23,588 — — — — Total derivative assets $ — $ 56,258 $ 81,859 $ 138,117 $ — $ 32,082 $ 80,268 $ 112,350 Liabilities Interest rate swaps $ — $ 128,301 $ — $ 128,301 $ — $ 7,887 $ — $ 7,887 Commodity contracts — — — — — — — — Foreign currency contracts — 10,946 — 10,946 — 36 — 36 Total derivative liabilities $ — $ 139,247 $ — $ 139,247 $ — $ 7,923 $ — $ 7,923
Changes in Fair Value of Derivative Instruments Classified as Level 3	The following table reconciles the changes in the fair value of derivative instruments classified as Level 3 in the fair value hierarchy for the three and six months ended June 30, 2018 and 2017: Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2018 2017 2018 2017 Beginning balance $ 60,148 $ 87,318 $ 80,268 $ 66,138 Realized and unrealized gains (losses): Included in other comprehensive income (loss) 9,503 (7,634 ) (10,507 ) 10,628 Included in operating revenues, net 14,016 (741 ) 15,549 5,424 Settlements (1,808 ) (2,153 ) (3,451 ) (5,400 ) Balance as of June 30 $ 81,859 $ 76,790 $ 81,859 $ 76,790
Significant Unobservable Inputs Used in Valuation of Commodity Contracts	The significant unobservable inputs used in the valuation of the Company's commodity contracts categorized as Level 3 in the fair value hierarchy as of June 30, 2018 are as follows: (In thousands, except range) Fair Value as of Transaction Type Assets Liabilities Valuation Technique Unobservable Inputs Range Commodity contracts - power $ 81,859 $ — Discounted cash flow Forward price (per MWh) $ 11.4 - $ 125.5 Option model Volatilities 3.0 % - 7.4 %
Sensitivity of Fair Value Measurements	The sensitivity of the Company’s fair value measurements to increases (decreases) in the significant unobservable inputs is as follows: Significant Unobservable Input Position Impact on Fair Value Measurement Increase (decrease) in forward price Forward sale Decrease (increase) Increase (decrease) in implied volatilities Purchase option Increase (decrease)
Carrying Amount and Estimated Fair Value of Long-term Debt	The carrying amount and estimated fair value of the Company's long-term debt as of June 30, 2018 and December 31, 2017 is as follows: As of June 30, 2018 As of December 31, 2017 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt $ 5,961,116 $ 6,056,039 $ 3,598,800 $ 3,702,470

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Schedule of Changes In Common Stock Outstanding	The following table reflects the changes in TerraForm Power’s Class A common shares outstanding during the six months ended June 30, 2018 and 2017: Six Months Ended June 30, 2018 2017 Balance as of January 1 148,086,027 92,223,089 Issuance of Class A common stock to affiliates 60,975,609 — Shares issued under equity incentive plan — 45,385 Balance as of June 30 209,061,636 92,268,474
Schedule of Restricted Stock Units	The following table presents information regarding outstanding RSUs as of June 30, 2018 and changes during the six months ended June 30, 2018: Number of RSUs Outstanding Aggregate Intrinsic Value (in millions) Weighted Average Remaining Balance as of January 1, 2018 — Granted 117,424 Balance as of June 30, 2018 117,424 $ 0.2 2.8 years
Dividends Declared	The following table presents cash dividends declared and paid on Class A common stock during the six months ended June 30, 2018. TerraForm Power did not declare or pay a dividend during the six months ended June 30, 2017. Dividends per Share Declaration Date Record Date Payment Date First Quarter $ 0.19 February 6, 2018 February 28, 2018 March 30, 2018 Second Quarter 0.19 April 30, 2018 June 1, 2018 June 15, 2018

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	6 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Basic and Diluted (Loss) Earnings Per Share of Class A Common Stock	Basic and diluted (loss) earnings per share of the Company's Class A common stock for the three and six months ended June 30, 2018 and 2017 was calculated as follows: Three Months Ended June 30, Six Months Ended June 30, (In thousands, except per share amounts) 2018 2017 2018 2017 Basic and diluted earnings (loss) per share: Net (loss) income attributable to Class A common stockholders $ (21,337 ) $ 9,606 $ 61,459 $ (21,191 ) Less: accretion of redeemable non-controlling interest — (2,187 ) — (4,413 ) Net (loss) income attributable to Class A common stockholders after accretion of redeemable non-controlling interests $ (21,337 ) $ 7,419 $ 61,459 $ (25,604 ) Weighted average basic Class A shares outstanding 1 161,568 92,257 154,890 92,165 Weighted average diluted Class A shares outstanding 2,3 161,568 92,745 154,905 92,165 Basic and diluted (loss) earnings per share $ (0.13 ) $ 0.08 $ 0.40 $ (0.28 ) ——— (1) Includes zero and 66 thousand contingently issuable shares for the three and six months ended June 30, 2018, respectively. (2) Includes zero and 29 thousand additional contingently issuable shares for the three and six months ended June 30, 2018, respectively. (3) The computation of diluted loss per share of the Company's Class A common stock for the three months ended June 30, 2018, excludes 117 thousand of potentially dilutive unvested RSUs because the effect would have been anti-dilutive. The computation of diluted earnings per share of the Company's Class A common stock for the six months ended June 30, 2018, includes 15 thousand of RSUs considered to be dilutive and calculated using the treasury stock method. The computation of diluted earnings per share of the Company's Class A common stock for the three months ended June 30, 2017 includes 487,950 of RSUs considered to be dilutive and calculated using the treasury stock method. The computation of diluted loss per share of the Company's Class A common stock for the six months ended June 30, 2017 excludes 1,524,317 of potentially dilutive unvested RSUs because the effect would have been anti-dilutive.

Segment Reporting (Tables)

Segment Reporting (Tables)	6 Months Ended
	Jun. 30, 2018
Segment Reporting [Abstract]
Summarized Financial Information of Reportable Segments	The following table reflects summarized financial information concerning the Company’s reportable segments for the three and six months ended June 30, 2018 and 2017 : Three Months Ended June 30, 2018 Three Months Ended June 30, 2017 (In thousands) Solar Wind Regulated Solar and Wind Corporate Total Solar Wind Corporate Total Operating revenues, net $ 83,321 $ 75,281 $ 21,286 $ — $ 179,888 $ 101,485 $ 68,882 $ — $ 170,367 Depreciation, accretion and amortization expense 27,141 35,269 7,194 390 69,994 27,900 34,604 718 63,222 Impairment of renewable energy facilities — — — — — 1,429 1,429 — — 1,429 Other operating costs and expenses 14,467 32,718 5,041 30,369 82,595 16,487 24,781 38,901 80,169 Interest expense (income), net 15,734 11,246 (4,753 ) 28,665 50,892 19,942 21,330 26,933 68,205 Gain on sale of renewable energy facilities — — — — — (37,116 ) — — (37,116 ) Other non-operating (income) expenses, net (2,558 ) 32 110 2,001 (415 ) (872 ) 75 (2,634 ) (3,431 ) Income tax expense (benefit) 1 — 364 2,174 1,896 4,434 — — (588 ) (588 ) Net income (loss) $ 28,537 $ (4,348 ) $ 11,520 $ (63,321 ) $ (27,612 ) $ 73,715 $ (11,908 ) $ (63,330 ) $ (1,523 ) ——— (1) Income tax expense (benefit) is not allocated to the Company’s segments, except for certain foreign jurisdictions. Six Months Ended June 30, 2018 Six Months Ended June 30, 2017 (In thousands) Solar Wind Regulated Solar and Wind Corporate Total Solar Wind Corporate Total Operating revenues, net $ 143,044 $ 143,105 $ 21,286 $ — $ 307,435 $ 167,486 $ 154,016 $ — $ 321,502 Depreciation, accretion and amortization expense 54,742 72,934 7,194 714 135,584 54,675 68,055 1,479 124,209 Impairment of renewable energy facilities 15,240 — — — 15,240 1,429 — — 1,429 Other operating costs and expenses 28,683 58,532 5,041 59,105 151,361 30,395 49,942 77,912 158,249 Interest expense (income), net 30,256 22,015 (4,753 ) 56,928 104,446 39,523 42,229 54,765 136,517 Gain on sale of renewable energy facilities — — — — — (37,116 ) — — (37,116 ) Other non-operating (income) expenses, net (2,558 ) 885 110 2,888 1,325 (914 ) 623 (2,193 ) (2,484 ) Income tax (benefit) expense 1 — 364 2,174 866 3,404 — — (1,157 ) (1,157 ) Net income (loss) $ 16,681 $ (11,625 ) $ 11,520 $ (120,501 ) $ (103,925 ) $ 79,494 $ (6,833 ) $ (130,806 ) $ (58,145 ) Balance Sheet Total assets 2 $ 2,823,676 $ 4,250,855 $ 2,458,868 $ 167,426 $ 9,700,825 $ 2,897,036 $ 3,400,858 $ 89,127 $ 6,387,021 ——— (1) Income tax expense (benefit) is not allocated to the Company’s segments, except for certain foreign jurisdictions. (2) Represents total assets as of June 30, 2018 and December 31, 2017 , respectively.

Accumulated Other Comprehensi42

Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income	: (In thousands) Foreign Currency Translation Adjustments Hedging Activities 1 Accumulated Other Comprehensive Income Balance as of December 31, 2016 $ (22,133 ) $ 45,045 $ 22,912 Net unrealized gain arising during the period (net of zero and $4,480 tax expense, respectively) 5,601 10,622 16,223 Reclassification of net realized loss (gain) into earnings (net of tax benefit of $8,858 and tax expense of $406) 14,741 (621 ) 14,120 Other comprehensive income 20,342 10,001 30,343 Accumulated other comprehensive (loss) income (1,791 ) 55,046 53,255 Less: Other comprehensive (loss) income attributable to non-controlling interests (717 ) 11,839 11,122 Balance as of June 30, 2017 $ (1,074 ) $ 43,207 $ 42,133 (In thousands) Foreign Currency Translation Adjustments Hedging Activities 1 Accumulated Other Comprehensive Income Balance as of December 31, 2017 $ (13,412 ) $ 61,430 $ 48,018 Cumulative-effect adjustment net of tax expense of $1,579 2) — (4,164 ) (4,164 ) Other comprehensive loss: Net unrealized (loss) gain arising during the period (net of zero tax impact) (8,675 ) 1,907 (6,768 ) Reclassification of net realized gain into earnings (net of zero tax impact) — (923 ) (923 ) Other comprehensive loss (8,675 ) 984 (7,691 ) Accumulated other comprehensive (loss) income (22,087 ) 58,250 36,163 Less: Other comprehensive loss attributable to non-controlling interests — (1,237 ) (1,237 ) Balance as of June 30, 2018 $ (22,087 ) $ 59,487 $ 37,400 ——— (1) See Note 10 . Derivatives for further breakout of hedging gains and losses between interest rate swaps and commodity contracts. (2) See Note 2. Summary of Significant Accounting Policies for discussion regarding the Company’s adoption of ASU No. 2017-12 as of January 1, 2018.

Non-controlling Interests (Tabl

Non-controlling Interests (Tables)	6 Months Ended
	Jun. 30, 2018
Noncontrolling Interest [Abstract]
Effect of the Corrections of Previously Reported Consolidated Financial Statements	The tables below summarize the effect of the corrections of the previously reported consolidated financial statement line items: Condensed Consolidated Balance Sheet March 31, 2018 (In thousands) As Previously Reported Adjustment Revised Deferred income taxes $ 16,839 $ 6,282 $ 23,121 Total liabilities 3,928,671 6,282 3,934,953 Redeemable non-controlling interests 50,760 (23,189 ) 27,571 Additional paid-in capital 1,841,692 5,919 1,847,611 Accumulated deficit (290,818 ) 10,988 (279,830 ) Total TerraForm Power, Inc. stockholders’ equity 1,576,008 16,907 1,592,915 Total stockholders’ equity 2,279,350 16,907 2,296,257 Consolidated Balance Sheet December 31, 2017 (In thousands) As Previously Reported Adjustment Revised Deferred income taxes $ 18,636 $ 6,336 $ 24,972 Total liabilities 3,958,313 6,336 3,964,649 Redeemable non-controlling interests 58,340 (23,680 ) 34,660 Additional paid-in capital 1,866,206 5,919 1,872,125 Accumulated deficit (398,629 ) 11,425 (387,204 ) Total TerraForm Power, Inc. stockholders’ equity 1,510,369 17,344 1,527,713 Total stockholders’ equity 2,370,368 17,344 2,387,712 Consolidated Balance Sheet December 31, 2016 (In thousands) As Previously Reported Adjustment Revised Deferred income taxes $ 27,723 $ 2,897 $ 30,620 Total liabilities 4,807,499 2,897 4,810,396 Redeemable non-controlling interests 180,367 (14,392 ) 165,975 Accumulated deficit (234,440 ) 7,390 (227,050 ) Total TerraForm Power, Inc. stockholders’ equity 1,252,957 7,390 1,260,347 Non-controlling interests 1,465,042 4,105 1,469,147 Total stockholders’ equity 2,717,999 11,495 2,729,494 Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) Three Months Ended March 31, 2018 Three Months Ended March 31, 2017 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax benefit $ (976 ) $ (54 ) $ (1,030 ) $ (918 ) $ 349 $ (569 ) Net loss (76,367 ) 54 (76,313 ) (56,273 ) (349 ) (56,622 ) Net (loss) income attributable to redeemable non-controlling interests (2,513 ) 491 (2,022 ) 835 (1,828 ) (993 ) Net (loss) income attributable to non-controlling interests (157,087 ) — (157,087 ) (25,339 ) 507 (24,832 ) Net income (loss) attributable to Class A common stockholders 83,233 (437 ) 82,796 (31,769 ) 972 (30,797 ) Earnings (loss) per share of Class A common stock - Basic and diluted 0.56 — 0.56 (0.37 ) 0.01 (0.36 ) Total comprehensive loss (91,104 ) 54 (91,050 ) (39,925 ) (349 ) (40,274 ) Comprehensive loss attributable to non-controlling interests (160,843 ) 491 (160,352 ) (17,614 ) (1,321 ) (18,935 ) Comprehensive income (loss) attributable to Class A common stockholders 69,739 (437 ) 69,302 (22,311 ) 972 (21,339 ) Consolidated Statements of Operations and Comprehensive Loss Three Months Ended December 31, 2017 Twelve Months Ended December 31, 2017 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax benefit $ (18,098 ) $ 713 $ (17,385 ) $ (23,080 ) $ 3,439 $ (19,641 ) Net loss (141,091 ) (713 ) (141,804 ) (232,864 ) (3,439 ) (236,303 ) Net loss excluding pre-acquisition net loss of renewable energy facilities acquired from SunEdison (141,091 ) (713 ) (141,804 ) (232,864 ) (3,439 ) (236,303 ) Net (loss) income attributable to redeemable non-controlling interests (7,278 ) (1,390 ) (8,668 ) 10,884 (9,288 ) 1,596 Net (loss) income attributable to non-controlling interests (20,514 ) 41 (20,473 ) (79,559 ) 1,814 (77,745 ) Net loss attributable to Class A common stockholders (113,299 ) 636 (112,663 ) (164,189 ) 4,035 (160,154 ) Loss per share of Class A common stock - Basic and diluted (0.82 ) — (0.82 ) (1.65 ) 0.04 (1.61 ) Total comprehensive loss (154,995 ) (713 ) (155,708 ) (192,458 ) (3,439 ) (195,897 ) Comprehensive loss attributable to non-controlling interests (33,023 ) (1,349 ) (34,372 ) (54,018 ) (7,474 ) (61,492 ) Comprehensive loss attributable to Class A common stockholders (121,972 ) 636 (121,336 ) (138,440 ) 4,035 (134,405 ) Condensed Consolidated Statements of Operations and Comprehensive Loss Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax benefit $ (2,633 ) $ 1,534 $ (1,099 ) $ (4,982 ) $ 2,726 $ (2,256 ) Net loss (34,820 ) (1,534 ) (36,354 ) (91,773 ) (2,726 ) (94,499 ) Net income attributable to redeemable non-controlling interests 6,803 (1,908 ) 4,895 18,162 (7,898 ) 10,264 Net loss attributable to non-controlling interests (15,077 ) 128 (14,949 ) (59,045 ) 1,773 (57,272 ) Net loss attributable to Class A common stockholders (26,546 ) 246 (26,300 ) (50,890 ) 3,399 (47,491 ) Loss per share of Class A common stock - Basic and diluted (0.31 ) — (0.31 ) (0.62 ) 0.03 (0.59 ) Total comprehensive loss (10,853 ) (1,534 ) (12,387 ) (37,463 ) (2,726 ) (40,189 ) Comprehensive income (loss) attributable to non-controlling interests 492 (1,780 ) (1,288 ) (20,995 ) (6,125 ) (27,120 ) Comprehensive loss attributable to Class A common stockholders (11,345 ) 246 (11,099 ) (16,468 ) 3,399 (13,069 ) Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) Three Months Ended June 30, 2017 Six Months Ended June 30, 2017 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax benefit $ (1,431 ) $ 843 $ (588 ) $ (2,349 ) $ 1,192 $ (1,157 ) Net loss (680 ) (843 ) (1,523 ) (56,953 ) (1,192 ) (58,145 ) Net income attributable to redeemable non-controlling interests 10,524 (4,162 ) 6,362 11,359 (5,990 ) 5,369 Net loss attributable to non-controlling interests (18,629 ) 1,138 (17,491 ) (43,968 ) 1,645 (42,323 ) Net income (loss) attributable to Class A common stockholders 7,425 2,181 9,606 (24,344 ) 3,153 (21,191 ) Earnings (loss) per share of Class A common stock - Basic and diluted 0.06 0.02 0.08 (0.31 ) 0.03 (0.28 ) Total comprehensive income (loss) 13,315 (843 ) 12,472 (26,610 ) (1,192 ) (27,802 ) Comprehensive loss attributable to non-controlling interests (3,873 ) (3,024 ) (6,897 ) (21,487 ) (4,345 ) (25,832 ) Comprehensive income (loss) attributable to Class A common stockholders 17,188 2,181 19,369 (5,123 ) 3,153 (1,970 ) Consolidated Statements of Operations and Comprehensive (Loss) Income Twelve Months Ended December 31, 2015 Twelve Months Ended December 31, 2016 (In thousands, except per share amounts) As Previously Reported Adjustment Revised As Previously Reported Adjustment Revised Income tax (benefit) expense $ (13,241 ) $ 657 $ (12,584 ) $ 494 $ 2,240 $ 2,734 Net loss (208,135 ) (657 ) (208,792 ) (241,507 ) (2,240 ) (243,747 ) Net loss subsequent to IPO and excluding pre-acquisition net loss of renewable energy facilities acquired from SunEdison (209,745 ) (657 ) (210,402 ) (241,507 ) (2,240 ) (243,747 ) Net income attributable to redeemable non-controlling interests 8,512 (2,509 ) 6,003 18,365 (11,883 ) 6,482 Net loss attributable to non-controlling interest (138,371 ) 798 (137,573 ) (130,025 ) 3,307 (126,718 ) Net loss attributable to Class A common stockholders (79,886 ) 1,054 (78,832 ) (129,847 ) 6,336 (123,511 ) Loss per share of Class A common stock - Basic and diluted (1.25 ) 0.01 (1.24 ) (1.47 ) 0.07 (1.40 ) Total comprehensive loss (195,005 ) (657 ) (195,662 ) (240,665 ) (2,240 ) (242,905 ) Comprehensive loss subsequent to IPO and excluding pre-acquisition comprehensive income (loss) of renewable energy facilities acquired from SunEdison (236,631 ) (657 ) (237,288 ) (240,665 ) (2,240 ) (242,905 ) Comprehensive loss attributable to non-controlling interests (141,266 ) (1,711 ) (142,977 ) (110,830 ) (8,576 ) (119,406 ) Comprehensive loss attributable to Class A common stockholders (95,365 ) 1,054 (94,311 ) (129,835 ) 6,336 (123,499 )
Activity of Redeemable Non-controlling Interests	The following table presents the activity of the redeemable non-controlling interests balance for the six months ended June 30, 2018: (In thousands) Redeemable Non-controlling Interests Balance as of December 31, 2017 $ 34,660 Cumulative-effect adjustment 1 (4,485 ) Redeemable non-controlling interests acquired in business combination 2 55,117 Distributions (1,118 ) Net loss 2,658 Foreign exchange differences (283 ) Balance as of June 30, 2018 $ 86,549 ——— (1) See discussion in Note 2. Summary of Significant Accounting Policies regarding the Company’s adoption of ASU No. 2014-09 and ASU No. 2016-08 as of January 1, 2018. (2) See Note 4. Acquisitions and Dispositions .

Nature of Operations and Basi44

Nature of Operations and Basis of Presentation (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 11, 2018	Oct. 16, 2017	Jun. 30, 2018
Noncontrolling Interest [Line Items]
Issuance of Class A common stock to affiliates			$ 650,000
Subsidiaries | Brookfield Asset Management
Noncontrolling Interest [Line Items]
Percentage of voting securities held		51.00%
Share Purchase Agreement
Noncontrolling Interest [Line Items]
Issuance of Class A common stock to affiliates (in shares)	60,975,609
Price of shares issued (in dollars per share)	$ 10.66
Issuance of Class A common stock to affiliates	$ 650,000
TerraForm Power | Share Purchase Agreement | Affiliates of Brookfield
Noncontrolling Interest [Line Items]
Percentage of ownership	65.00%

Summary of Significant Accoun45

Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended
		Jun. 30, 2018	Dec. 31, 2018	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Accounting Policies [Line Items]
Non-current restricted cash reclassified to current		$ 15,500		$ 15,500		$ 18,800
Cash and cash equivalents reclassified to current restricted cash		8,000		8,000		21,700
Decline in non-controlling interests balance				$ 151,200
Cumulative-effect adjustment, decrease (increase) in accumulated deficit	[1]					20,106
ITC recapture period				5 years
Decrease in non-cash deferred revenue recognition				$ 929	$ 6,069
Severance and transition bonus costs
Accounting Policies [Line Items]
Additional severance and transition bonus costs		1,000		2,300
Payments related to the restructuring		1,400		2,200
Accrued severance and transition bonuses		2,800		2,800
Accounting Standards Update 2014-09
Accounting Policies [Line Items]
Decrease in non-cash deferred revenue recognition		$ 1,600		$ 5,100
Accumulated Deficit
Accounting Policies [Line Items]
Cumulative-effect adjustment, decrease (increase) in accumulated deficit	[1]					24,578
Accumulated Deficit | Accounting Standards Update 2014-09 | ITCs
Accounting Policies [Line Items]
Cumulative-effect adjustment, decrease (increase) in accumulated deficit						40,900
Non-controlling interests
Accounting Policies [Line Items]
Cumulative-effect adjustment, decrease (increase) in accumulated deficit	[1]					(308)
Accumulated Other Comprehensive Income (Loss)
Accounting Policies [Line Items]
Cumulative-effect adjustment, decrease (increase) in accumulated deficit	[1]					(4,164)
Cumulative effect adjustment, tax						1,600
Scenario, Forecast | Accounting Standards Update 2014-09
Accounting Policies [Line Items]
Decrease in non-cash deferred revenue recognition			$ 11,200
REC sale arrangements | Accumulated Deficit | Accounting Standards Update 2014-09
Accounting Policies [Line Items]
Cumulative-effect adjustment, decrease (increase) in accumulated deficit						(20,500)
REC sale arrangements | Non-controlling interests | Accounting Standards Update 2014-09
Accounting Policies [Line Items]
Cumulative-effect adjustment, decrease (increase) in accumulated deficit						(300)
REC sale arrangements | Redeemable Non-controlling Interests | Accounting Standards Update 2014-09
Accounting Policies [Line Items]
Cumulative-effect adjustment, decrease (increase) in accumulated deficit						$ (4,500)
[1]	See Note 2. Summary of Significant Accounting Policies for discussion regarding the Company’s adoption of Accounting Standards Update (“ASU”) No. 2014-09, ASU No. 2016-08 and ASU No. 2017-12 as of January 1, 2018.

Summary of Significant Accoun46

Summary of Significant Accounting Policies - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Cash and cash equivalents	$ 339,209	$ 128,087
Restricted cash - current	38,823	54,006
Restricted cash - non-current	138,053	42,694
Cash, cash equivalents and restricted cash shown in the unaudited condensed consolidated statement of cash flows	$ 516,085	$ 224,787	$ 862,910	$ 682,837

Revenue - Impact on Statement o

Revenue - Impact on Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	$ 179,888						$ 307,435
Amortization of rate contracts	(9,750)						(19,567)
Operating costs and expenses	152,589				$ 144,820		302,185	$ 283,887
Operating (loss) income	27,299				25,547		5,250	37,615
Other expenses, net	50,477				27,658		105,771	96,917
Loss before income tax expense (benefit)	(23,178)				(2,111)		(100,521)	(59,302)
Income tax expense (benefit)	4,434	$ (1,030)	$ (17,385)	$ (1,099)	(588)	$ (569)	3,404	(1,157)	$ (2,256)	$ (19,641)	$ 2,734	$ (12,584)
Net loss	(27,612)	$ (76,313)	$ (141,804)	$ (36,354)	$ (1,523)	$ (56,622)	(103,925)	$ (58,145)	$ (94,499)	$ (236,303)	$ (243,747)	$ (208,792)
Amounts excluding Topic 606 Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	187,072						315,577
Amortization of rate contracts	(9,750)						(19,567)
Operating costs and expenses	152,589						302,185
Operating (loss) income	34,483						13,392
Other expenses, net	50,477						105,771
Loss before income tax expense (benefit)	(15,994)						(92,379)
Income tax expense (benefit)	4,434						3,404
Net loss	(20,428)						(95,783)
Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	83,321						143,044
Amortization of rate contracts	(1,966)						(3,943)
Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	75,281						143,105
Amortization of rate contracts	(7,784)						(15,624)
Regulated Wind and Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	21,286						21,286
PPA rental income
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	106,265						195,446
PPA rental income | Amounts excluding Topic 606 Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	106,265						195,446
PPA rental income | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	55,366						92,134
PPA rental income | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	50,899						103,312
Commodity derivatives
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	21,441						32,448
Commodity derivatives | Amounts excluding Topic 606 Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	21,441						32,448
Commodity derivatives | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	0						0
Commodity derivatives | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	21,441						32,448
PPA revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	19,817						33,016
PPA revenue | Amounts excluding Topic 606 Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	19,817						33,016
PPA revenue | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	13,458						19,965
PPA revenue | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	6,359						13,051
Regulated solar and wind revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	21,286						21,286
Regulated solar and wind revenue | Amounts excluding Topic 606 Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	21,286						21,286
Regulated solar and wind revenue | Regulated Wind and Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	21,286						21,286
Energy revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	159,059						262,629
Energy revenue | Amounts excluding Topic 606 Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	159,059						262,629
Energy revenue | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	66,858						108,156
Energy revenue | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	70,915						133,187
Energy revenue | Regulated Wind and Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	21,286						21,286
Incentive revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	20,829						44,806
Incentive revenue | Amounts excluding Topic 606 Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	28,013						52,948
Incentive revenue | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	16,463						34,888
Incentive revenue | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	4,366						9,918
REC Sales | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	5,586						3,026
Operating costs and expenses	0						0
Operating (loss) income	5,586						3,026
Other expenses, net	0						0
Loss before income tax expense (benefit)	5,586						3,026
Income tax expense (benefit)	0						0
Net loss	5,586						3,026
ITC Sales | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue	1,598						5,116
Operating costs and expenses	0						0
Operating (loss) income	1,598						5,116
Other expenses, net	0						0
Loss before income tax expense (benefit)	1,598						5,116
Income tax expense (benefit)	0						0
Net loss	$ 1,598						$ 5,116

Revenue - Impact on Balance She

Revenue - Impact on Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	$ 161,017		$ 89,680
Other current assets	451,523
Total current assets	612,540		341,536
Non-current assets	9,088,285
Total assets	9,700,825		6,387,021
Deferred revenue	1,735		17,859
Other current liabilities	684,516
Total current liabilities	686,251		513,853
Deferred revenue, less current portion	12,780		38,074
Other non-current liabilities	6,028,547
Total liabilities	6,727,578	$ 3,934,953	3,964,649	$ 4,810,396
Redeemable non-controlling interests and total stockholders' equity	2,973,247
Total liabilities, redeemable non-controlling interests and stockholders' equity	9,700,825		$ 6,387,021
Amounts excluding Topic 606 Adoption
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	189,318
Other current assets	451,523
Total current assets	640,841
Non-current assets	9,088,285
Total assets	9,729,126
Deferred revenue	18,045
Other current liabilities	684,516
Total current liabilities	702,561
Deferred revenue, less current portion	32,251
Other non-current liabilities	6,028,547
Total liabilities	6,763,359
Redeemable non-controlling interests and total stockholders' equity	2,965,767
Total liabilities, redeemable non-controlling interests and stockholders' equity	9,729,126
REC Sales | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Accounts receivable, net	28,301
Other current assets	0
Total current assets	28,301
Non-current assets	0
Total assets	28,301
Redeemable non-controlling interests and total stockholders' equity	28,301
Total liabilities, redeemable non-controlling interests and stockholders' equity	28,301
ITC Sales | Adjustments | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Deferred revenue	16,310
Other current liabilities	0
Total current liabilities	16,310
Deferred revenue, less current portion	19,471
Other non-current liabilities	0
Total liabilities	35,781
Redeemable non-controlling interests and total stockholders' equity	(35,781)
Total liabilities, redeemable non-controlling interests and stockholders' equity	$ 0

Revenue - Remaining Performance

Revenue - Remaining Performance Obligation (Details) - USD ($) $ in Millions	Jun. 30, 2018	Mar. 31, 2018
REC Sales | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-07-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue	$ 59.8
Deferred revenue, recognition period	5 years
Amounts excluding Topic 606 Adoption | ITC Sales
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Deferred revenue	$ 5.1	$ 1.6

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2018
Revenue from External Customer [Line Items]
Revenue	$ 179,888	$ 307,435
Revenue recognized related to contract liability		929	$ 6,069
PPA revenue
Revenue from External Customer [Line Items]
Revenue	19,817	33,016
Accounts receivable	6,800	$ 6,800
Payment term		30 days
Solar incentive revenue
Revenue from External Customer [Line Items]
Revenue	21,300	$ 21,100
Accounts receivable	77,100	$ 77,100
REC Sales
Revenue from External Customer [Line Items]
Payment term		30 days
Facility Linked Incentive Contracts
Revenue from External Customer [Line Items]
Revenue	8,800	$ 14,300
Accounts receivable	5,800	5,800
ITC Sales
Revenue from External Customer [Line Items]
Contract liability	5,600	5,600
Revenue recognized related to contract liability	400	700
ITC Sales - Government Incentives
Revenue from External Customer [Line Items]
Deferred revenue	9,000	9,000
Accounting Standards Update 2014-09
Revenue from External Customer [Line Items]
Revenue recognized related to contract liability	1,600	5,100
Adjustments | Accounting Standards Update 2014-09 | REC Sales
Revenue from External Customer [Line Items]
Revenue	5,586	3,026
Adjustments | Accounting Standards Update 2014-09 | ITC Sales
Revenue from External Customer [Line Items]
Revenue	1,598	5,116
Amounts excluding Topic 606 Adoption
Revenue from External Customer [Line Items]
Revenue	187,072	315,577
Amounts excluding Topic 606 Adoption | PPA revenue
Revenue from External Customer [Line Items]
Revenue	19,817	33,016
Amounts excluding Topic 606 Adoption | ITC Sales
Revenue from External Customer [Line Items]
Deferred revenue	$ 5,100	$ 5,100		$ 1,600

Acquisitions and Dispositions -

Acquisitions and Dispositions - Narrative (Details) $ in Thousands, £ in Millions	Jul. 02, 2018USD ($)	Jun. 12, 2018USD ($)	May 11, 2017USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)MW	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)MW	Jun. 08, 2018	Feb. 07, 2018€ / shares	Feb. 07, 2018USD ($)MW	Sep. 30, 2017USD ($)MW	May 11, 2017GBP (£)power_plantMW	May 11, 2017USD ($)power_plantMW
Business Acquisition [Line Items]
Proceeds from issuance of Class A common stock to affiliates		$ 650,000				$ 650,000	$ 0
Borrowings of non-recourse long-term debt		$ 471,000
Acquisition-related costs				$ 8,900		12,600
Acquisition-related costs - affiliate				6,025	$ 0	6,630	0
Repayments of long-term debt						1,750	0
Gain on sale of renewable energy facilities				0	(37,116)	0	(37,116)
Saeta
Business Acquisition [Line Items]
Percentage acquired		95.28%								100.00%
Share price (in euros per share) | € / shares									€ 12.20
Percentage of voting interests accepted to be acquired								95.00%
Consideration transferred		$ 1,120,000
Long-term debt, including current portion		1,910,000								$ 1,906,831
Purchase price for acquisition		82,000
Operating revenues of acquiree				24,700		24,700
Net income of acquiree				$ 11,000		11,200
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW											0.3
Power Plants Sold In The United Kingdom | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW												365	365
Number of operating projects | power_plant												24	24
Sale to Vortex Solar | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW												11.1	11.1
Number of operating projects | power_plant												1	1
Consideration received													$ 214,100
Transaction expenses			$ 3,900
Cash and cash equivalents													14,800
Restricted cash													$ 21,800
Reduction of non-recourse project debt | £												£ 301
Gain on sale of renewable energy facilities					$ 37,100		$ 37,100
Enfinity Colorado DHA 1
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW					2.5		2.5
Membership interest sold							100.00%
TerraForm Resi Solar Manager
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW					8.9		8.9
Membership interest sold							100.00%
TerraForm Resi Manager and Enfinity Colorado DHA 1
Business Acquisition [Line Items]
Consideration received					$ 1,100		$ 1,100				$ 6,000
Cash and cash equivalents					600		600
Restricted cash					$ 800		$ 800
Subsequent Event | Saeta
Business Acquisition [Line Items]
Percentage acquired	4.72%
Consideration transferred	$ 54,600
Regulated solar and wind revenue | Saeta
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW										1,028
Wind | Saeta
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW										249.5
Solar | Saeta
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW										778
Sponsor Line Agreement | Revolving Credit Facility
Business Acquisition [Line Items]
Borrowings of non-recourse long-term debt		30,000
New Revolver | Revolving Credit Facility
Business Acquisition [Line Items]
Borrowings of non-recourse long-term debt		$ 359,000
Secured Debt
Business Acquisition [Line Items]
Repayments of long-term debt						$ 30,000

Acquisitions and Dispositions52

Acquisitions and Dispositions - Acquisition Price Allocation table (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 12, 2018	Feb. 07, 2018	Dec. 31, 2017
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Goodwill	$ 114,780			$ 0
Saeta
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net [Abstract]
Renewable energy facilities in service			$ 1,988,993
Accounts receivable			90,555
Intangible assets			992,883
Goodwill			115,381
Other assets			44,190
Total assets acquired			3,232,002
Accounts payable, accrued expenses and other current liabilities			92,965
Long-term debt, including current portion		$ 1,910,000	1,906,831
Deferred income taxes			174,080
Asset retirement obligations			11,454
Derivative liabilities			137,002
Other long-term liabilities			23,069
Total liabilities assumed			2,345,401
Redeemable non-controlling interests			55,117
Purchase price, net of cash and restricted cash acquired			831,484
Cash and cash equivalents acquired			187,200
Restricted cash acquired			$ 95,100

Acquisitions and Dispositions53

Acquisitions and Dispositions - Intangibles at Acquisitions Date (Details) - Saeta $ in Thousands	Feb. 07, 2018USD ($)
Business Acquisition [Line Items]
Fair Value (In thousands)	$ 992,883
Concessions and license agreements
Business Acquisition [Line Items]
Fair Value (In thousands)	$ 992,883
Weighted Average Amortization Period	17 years

Acquisitions and Dispositions54

Acquisitions and Dispositions - Pro Forma table (Details) - Saeta - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Business Acquisition [Line Items]
Total operating revenues, net	$ 496,268	$ 491,812
Net loss	$ (90,088)	$ (57,713)

Renewable Energy Facilities -

Renewable Energy Facilities - Narrative (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017MW
Property, Plant and Equipment, Net, by Type [Abstract]
Total renewable energy facilities, net	$ 6,634,926		$ 6,634,926			$ 4,801,925
Depreciation expense	57,800	$ 54,400	115,000	$ 106,600
Impairment of renewable energy facilities	0	$ 1,429	15,240	$ 1,429
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Property, Plant and Equipment, Net, by Type [Abstract]
Capacity of power plant (MW) | MW							0.3
Renewable Energy Facilities in Service
Property, Plant and Equipment, Net, by Type [Abstract]
Renewable energy facilities, gross	7,316,084		7,316,084			5,378,462
Less: accumulated depreciation - renewable energy facilities	(683,260)		(683,260)			(578,474)
Total renewable energy facilities, net	6,632,824		6,632,824			4,799,988
Construction in Progress - Renewable Energy Facilities
Property, Plant and Equipment, Net, by Type [Abstract]
Renewable energy facilities, gross	$ 2,102		2,102			$ 1,937
REC Sales Agreement
Property, Plant and Equipment, Net, by Type [Abstract]
Renewable energy facilities, gross					$ 19,500
Fair value of operating project					$ 4,300
Impairment of renewable energy facilities			$ 15,200

Intangible Assets, Net and Go56

Intangible Assets, Net and Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2017
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	$ 39,686		$ 39,686			$ 41,086
Accumulated Amortization	(20,548)		(20,548)			(18,744)
Net Book Value	19,138		19,138			22,342
Total intangible assets, net
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	2,247,142		2,247,142			1,255,762
Accumulated Amortization	(213,288)		(213,288)			(177,976)
Net Book Value	2,033,854		2,033,854			1,077,786
Total intangible assets, net | Operating revenues, net
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Amortization	9,800	$ 9,700	19,600	$ 19,500
Total intangible assets, net | Depreciation, Accretion, and Amortization
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Amortization	10,500	6,600	16,900	13,000
Concession and licensing contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	990,497		990,497
Accumulated Amortization	(2,953)		(2,953)
Net Book Value	987,544		987,544
Concession and licensing contracts | Operating revenues, net
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Amortization	2,900	0	$ 2,900	0
Concession and licensing contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			17 years
Favorable rate revenue contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	713,066		$ 713,066			718,639
Accumulated Amortization	(120,975)		(120,975)			(102,543)
Net Book Value	592,091		$ 592,091			616,096
Favorable rate revenue contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			14 years		15 years
In-place value of market rate revenue contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	527,779		$ 527,779			521,323
Accumulated Amortization	(86,631)		(86,631)			(73,104)
Net Book Value	441,148		$ 441,148			448,219
In-place value of market rate revenue contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			18 years		19 years
Favorable rate land leases
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	15,800		$ 15,800			15,800
Accumulated Amortization	(2,729)		(2,729)			(2,329)
Net Book Value	13,071		$ 13,071			13,471
Favorable rate land leases | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			17 years		17 years
Unfavorable rate revenue contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	33,686		$ 33,686			35,086
Accumulated Amortization	(17,181)		(17,181)			(16,030)
Net Book Value	16,505		$ 16,505			19,056
Unfavorable rate revenue contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			7 years		7 years
Unfavorable rate operations and maintenance contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	5,000		$ 5,000			5,000
Accumulated Amortization	(3,177)		(3,177)			(2,552)
Net Book Value	1,823		$ 1,823			2,448
Unfavorable rate operations and maintenance contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			1 year		2 years
Unfavorable rate land lease
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	1,000		$ 1,000			1,000
Accumulated Amortization	(190)		(190)			(162)
Net Book Value	810		$ 810			$ 838
Unfavorable rate land lease | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			15 years		15 years
Lease agreements | Cost of Operations
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Amortization	$ (300)	$ (300)	$ (200)	$ (300)

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Thousands	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)	Jun. 30, 2017MW
Consolidated Variable Interest Entity, Primary Beneficiary
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Current assets	$ 131,080	$ 142,403
Non-current assets	4,062,705	4,155,558
Total assets	4,193,785	4,297,961
Current liabilities	99,330	119,021
Non-current liabilities	1,072,324	975,839
Total liabilities	$ 1,171,654	$ 1,094,860
TerraForm Resi Manager
Variable Interest Entity [Line Items]
Capacity of power plant (MW) | MW			8.9

Long-term Debt - Debt Schedule

Long-term Debt - Debt Schedule (Details) - USD ($)	May 11, 2018	Feb. 06, 2018	Oct. 16, 2017	Jun. 30, 2018	Jun. 30, 2017	Feb. 07, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total principal due for long-term debt and financing lease obligations				$ 5,996,376,000			$ 3,642,516,000
Unamortized discount, net				(17,462,000)			(19,027,000)
Deferred financing costs, net				(17,798,000)			(24,689,000)
Less current portion of long-term debt and financing lease obligations				(458,177,000)			(403,488,000)
Long-term debt and financing lease obligations, less current portion				$ 5,502,939,000			3,195,312,000
Interest rate				4.93%
Revolving credit facility draws				$ 539,053,000	$ 0
Revolving Credit Facility | Sponsor Line Agreement
Debt Instrument [Line Items]
Total principal due for long-term debt and financing lease obligations				$ 86,000,000			0
Interest rate				5.05%
Maximum borrowing capacity			$ 500,000,000
Secured Debt
Debt Instrument [Line Items]
Total principal due for long-term debt and financing lease obligations				$ 3,499,216,000			1,616,729,000
Interest rate				4.92%
Fixed interest rate				74.00%
Variable interest rate				26.00%
Secured Debt | Senior Notes due 2023
Debt Instrument [Line Items]
Total principal due for long-term debt and financing lease obligations				$ 500,000,000			500,000,000
Interest rate				4.25%
Secured Debt | Senior Notes due 2025
Debt Instrument [Line Items]
Total principal due for long-term debt and financing lease obligations				$ 300,000,000			300,000,000
Interest rate				6.63%
Secured Debt | 5.00% Senior Notes Due 2028
Debt Instrument [Line Items]
Total principal due for long-term debt and financing lease obligations				$ 700,000,000			700,000,000
Interest rate				5.00%
Secured Debt | New Term Loan
Debt Instrument [Line Items]
Total principal due for long-term debt and financing lease obligations				$ 348,250,000			350,000,000
Interest rate				3.98%
Debt instrument, reduction in interest rate	0.75%
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Total principal due for long-term debt and financing lease obligations				$ 451,362,000			60,000,000
Interest rate				4.93%
Line of Credit | Revolving Credit Facility | New Revolver
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 450,000,000				$ 600,000,000
Financing lease obligations
Debt Instrument [Line Items]
Total principal due for long-term debt and financing lease obligations				$ 111,548,000			$ 115,787,000
Interest rate				5.60%
Saeta | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity		147,000,000
Revolving credit facility draws		$ 9,400,000
LIBOR | Revolving Credit Facility
Debt Instrument [Line Items]
Period for commitment to receive LIBOR loans			3 years

Long-term Debt - Non-recourse L

Long-term Debt - Non-recourse Long-term Debt Narrative (Details)	Jun. 06, 2018USD ($)subsidiaryMW	Jun. 30, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Defaulted debt, reclassified to current		$ 199,700,000	$ 239,700,000
Permanent Financing | Non-recourse Project Financing
Debt Instrument [Line Items]
Number of subsidiaries | subsidiary	1
Face amount of senior notes issued	$ 83,000,000
Debt interest rate	4.59%
Capacity of power plant (MW) | MW	73
Debt instrument, amortization period	22 years

Long-term Debt - Indebtedness A

Long-term Debt - Indebtedness Assumed in Business Combination (Details) - Saeta - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 12, 2018	Feb. 07, 2018
Debt Instrument [Line Items]
Debt assumed in acquisition		$ 1,910,000	$ 1,906,831
Minimum
Debt Instrument [Line Items]
Debt interest rate	1.10%
Maximum
Debt Instrument [Line Items]
Debt interest rate	6.72%

Long-term Debt - Maturities (De

Long-term Debt - Maturities (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Aggregate Contractual Payments of Long-term Debt
Remainder of 2018	$ 120,727
2,019	251,675
2,020	254,507
2,021	696,995
2,022	746,954
Thereafter	3,925,518
Total	5,996,376
Defaulted debt, reclassified to current	199,700	$ 239,700
Long-term Debt
Aggregate Contractual Payments of Long-term Debt
Defaulted debt, reclassified to current	$ 199,700

Income Taxes - Components of In

Income Taxes - Components of Income Tax Provision (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Loss before income tax expense (benefit)	$ (23,178)				$ (2,111)		$ (100,521)	$ (59,302)
Income tax expense (benefit)	$ 4,434	$ (1,030)	$ (17,385)	$ (1,099)	$ (588)	$ (569)	$ 3,404	$ (1,157)	$ (2,256)	$ (19,641)	$ 2,734	$ (12,584)
Effective tax rate	(19.10%)				27.90%		(3.40%)	2.00%

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Ownership percentage of Terra LLC	65.80%				65.80%		65.80%	65.80%
Income tax expense (benefit)	$ 4,434	$ (1,030)	$ (17,385)	$ (1,099)	$ (588)	$ (569)	$ 3,404	$ (1,157)	$ (2,256)	$ (19,641)	$ 2,734	$ (12,584)
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Deferred Tax Liability, Provisional Income Tax Benefit										$ 5,000
SunEdison
Income Taxes [Line Items]
Ownership percentage by other entities	34.20%				34.20%		34.20%	34.20%
Terra LLC | TerraForm Power
Income Taxes [Line Items]
Percentage acquired	100.00%						100.00%

Derivatives - Schedule of Fair

Derivatives - Schedule of Fair Values of Derivative Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017	Mar. 31, 2017
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	$ 184,497	$ 112,413
Gross assets offset in consolidated balance sheet	(46,380)	(63)
Net assets in consolidated balance sheet	138,117	112,350
Gross amounts of liabilities recognized	185,627	7,986
Gross liabilities offset in consolidated balance sheet	(46,380)	(63)
Net liabilities in consolidated balance sheet	139,247	7,923
Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	64,166	21,633
Gross assets offset in consolidated balance sheet	(45,924)	(63)
Net assets in consolidated balance sheet	18,242	21,570
Other assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	120,331	90,780
Gross assets offset in consolidated balance sheet	(456)	0
Net assets in consolidated balance sheet	119,875	90,780
Accounts payable, accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized	92,815	2,786
Gross liabilities offset in consolidated balance sheet	(45,924)	(63)
Net liabilities in consolidated balance sheet	46,891	2,723
Other long-term liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized		5,200	$ 92,812
Gross liabilities offset in consolidated balance sheet		0	(456)
Net liabilities in consolidated balance sheet		5,200	92,356
Interest Rate Swaps | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	12,080	4,686
Gross amounts of liabilities recognized	2,752	7,286
Interest Rate Swaps | Derivatives Designated as Hedging Instruments | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	908	0
Interest Rate Swaps | Derivatives Designated as Hedging Instruments | Other assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	11,172	4,686
Interest Rate Swaps | Derivatives Designated as Hedging Instruments | Accounts payable, accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized	600	2,490
Interest Rate Swaps | Derivatives Designated as Hedging Instruments | Other long-term liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized		4,796	2,152
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	456	0
Gross amounts of liabilities recognized	126,005	601
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	0	0
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments | Other assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	456	0
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments | Accounts payable, accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized	35,345	197
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments | Other long-term liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized		404	90,660
Commodity contracts | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	40,405	80,268
Gross amounts of liabilities recognized	0	0
Commodity contracts | Derivatives Designated as Hedging Instruments | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	1,200	8,961
Commodity contracts | Derivatives Designated as Hedging Instruments | Other assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	39,205	71,307
Commodity contracts | Derivatives Designated as Hedging Instruments | Accounts payable, accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized	0	0
Commodity contracts | Derivatives Designated as Hedging Instruments | Other long-term liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized		0	0
Commodity contracts | Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	62,044	27,396
Gross amounts of liabilities recognized	0	0
Commodity contracts | Derivatives Not Designated as Hedging Instruments | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	15,236	12,609
Commodity contracts | Derivatives Not Designated as Hedging Instruments | Other assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	46,808	14,787
Commodity contracts | Derivatives Not Designated as Hedging Instruments | Accounts payable, accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized	0	0
Commodity contracts | Derivatives Not Designated as Hedging Instruments | Other long-term liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized		0	0
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	69,512	63
Gross amounts of liabilities recognized	56,870	99
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments | Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	46,822	63
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments | Other assets
Derivatives, Fair Value [Line Items]
Gross amounts of assets recognized	22,690	0
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments | Accounts payable, accrued expenses and other current liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized	$ 56,870	99
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments | Other long-term liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of liabilities recognized		$ 0	$ 0

Derivatives - Schedule of Notio

Derivatives - Schedule of Notional Amounts for Derivative Instruments (Details) € in Thousands, £ in Thousands, MWh in Thousands, $ in Thousands, $ in Thousands	Jun. 30, 2017MWh	Dec. 31, 2016USD ($)MWh	Jun. 30, 2018GBP (£)	Jun. 30, 2018USD ($)	Jun. 30, 2018CAD ($)	Jun. 30, 2018EUR (€)	Dec. 31, 2017USD ($)	Dec. 31, 2017CAD ($)	Dec. 31, 2017EUR (€)	Mar. 31, 2016USD ($)
Interest rate swaps | Derivatives designated as hedges
Derivative [Line Items]
Notional amount				$ 371,560	$ 151,778		$ 395,986	$ 156,367
Interest rate swaps | Derivatives not designated as hedges
Derivative [Line Items]
Notional amount				$ 13,132		€ 1,065,137	$ 13,520		€ 0
Commodity contracts | Derivatives designated as hedges
Derivative [Line Items]
Notional amount (in MWhs)	6,334	15,579
Commodity contracts | Derivatives not designated as hedges
Derivative [Line Items]
Notional amount (in MWhs)	9,247	987
Foreign currency contracts | Derivatives not designated as hedges
Derivative [Line Items]
Notional amount		$ 0	£ 0					$ 9,875		$ 3,395,200

Derivatives - Gains and Losses

Derivatives - Gains and Losses on Derivatives Not Designated As Hedges (Details) - Derivatives not designated as hedges - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Interest expense, net | Interest rate swaps
Derivative [Line Items]
Loss (gain) on derivatives	$ (7,763)	$ 1,818	$ (7,989)	$ 3,192
Loss on foreign currency exchange, net | Foreign currency contracts
Derivative [Line Items]
Loss (gain) on derivatives	(13,792)	347	(12,566)	560
Operating revenues, net | Commodity contracts
Derivative [Line Items]
Loss (gain) on derivatives	$ (17,084)	$ (1,579)	$ (17,494)	$ (5,692)

Derivatives - Gains (Losses) Re

Derivatives - Gains (Losses) Recognized Related to Interest Rate Swaps and Commodity Contracts Designated as Cash Flow Hedges (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Derivative [Line Items]
Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, net of taxes	$ 12,399	$ (3,432)	$ 1,907	$ 10,622
Reclassification of net realized loss (gain) into earnings	39	(235)	(923)	(621)
Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, net of taxes	14,268	(3,432)	3,041	10,622
Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach	0	0	735	0
Reclassification of net realized loss (gain) into earnings	(439)	(235)	(1,069)	(621)
(Gain) Loss Excluded from the Assessment of Effectiveness that is Amortized through Earnings	(347)	2,572	(679)	3,574
Cash Flow Hedging | Interest rate swaps
Derivative [Line Items]
Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, net of taxes	2,645	(1,633)	10,520	(3,252)
Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach	0	0	0	0
Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, tax expense (benefit)	0	(500)	0	(500)
Cash Flow Hedging | Commodity contracts
Derivative [Line Items]
Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, net of taxes	11,623	(1,799)	(7,479)	13,874
Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach	0	0	735	0
Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, tax expense (benefit)	0	(3,700)	0	2,100
Cash Flow Hedging | Interest expense, net | Interest rate swaps
Derivative [Line Items]
Reclassification of net realized loss (gain) into earnings	292	(217)	973	2,644
(Gain) Loss Excluded from the Assessment of Effectiveness that is Amortized through Earnings	0	(322)	0	491
(Gain) Loss Included in the Assessment of Effectiveness Reclassified from AOCI into Income, tax expense (benefit)	0	(1,700)	0	(1,700)
Cash Flow Hedging | Operating revenues, net | Commodity contracts
Derivative [Line Items]
Reclassification of net realized loss (gain) into earnings	(731)	(18)	(2,042)	(3,265)
(Gain) Loss Excluded from the Assessment of Effectiveness that is Amortized through Earnings	(347)	2,894	(679)	3,083
(Gain) Loss Included in the Assessment of Effectiveness Reclassified from AOCI into Income, tax expense (benefit)	$ 0	$ (2,100)	$ 0	$ 2,100

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2018	Dec. 31, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense (income), net		$ 50,892,000	$ 68,205,000	$ 104,446,000	$ 136,517,000
Collateral already posted		0		0			$ 0
Gross amounts of liabilities recognized		185,627,000		185,627,000			7,986,000
Cumulative-effect adjustment	[1]						20,106,000
Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Interest expense (income), net					30,600,000
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Accumulated gain on derivative		42,100,000		42,100,000		$ 44,300,000
Gain on derivative		17,100,000	$ 5,800,000	$ 23,600,000	$ 11,200,000
Maximum term of outstanding interest rate swaps				10 years
Gain expected to be reclassified				$ 1,600,000
Letter of Credit | Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Collateral already posted		15,000,000		15,000,000
Secured Debt | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Loss expected to be reclassified into earnings		(400,000)		$ (400,000)
Maximum term of outstanding interest rate swaps				16 years
Derivatives designated as hedges | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gross amounts of liabilities recognized		2,752,000		$ 2,752,000			7,286,000
Derivatives designated as hedges | Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gross amounts of liabilities recognized		0		0			0
Derivatives not designated as hedges | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gross amounts of liabilities recognized		126,005,000		126,005,000			601,000
Derivatives not designated as hedges | Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gross amounts of liabilities recognized		0		0			0
Derivatives not designated as hedges | Secured Debt | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Related liabilities reclassified to current							500,000
Liabilities related to assets held for sale | Derivatives not designated as hedges | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gross amounts of liabilities recognized		0		0
Non-current liabilities related to assets held for sale | Derivatives not designated as hedges | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Gross amounts of liabilities recognized		$ 0		$ 0
Accumulated Other Comprehensive Income (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Cumulative-effect adjustment	[1]						(4,164,000)
Cumulative effect adjustment, tax							$ 1,600,000
[1]	See Note 2. Summary of Significant Accounting Policies for discussion regarding the Company’s adoption of Accounting Standards Update (“ASU”) No. 2014-09, ASU No. 2016-08 and ASU No. 2017-12 as of January 1, 2018.

Fair Value of Financial Instr69

Fair Value of Financial Instruments - Financial Instruments Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Assets and Liabilities
Assets	$ 138,117	$ 112,350
Liabilities	139,247	7,923
Long-term debt, including current portion
Carrying Amount	5,961,116	3,598,800
Fair Value	$ 6,056,039	$ 3,702,470
Senior Notes due 2023
Long-term debt, including current portion
Fair value as a percentage of face	96.50%	99.50%
Senior Notes due 2025
Long-term debt, including current portion
Fair value as a percentage of face	106.25%	109.50%
Senior Notes Due 2028
Long-term debt, including current portion
Fair value as a percentage of face	95.00%	99.38%
Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	$ 138,117	$ 112,350
Liabilities	139,247	7,923
Interest rate swaps | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	12,080	4,686
Liabilities	128,301	7,887
Commodity contracts | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	102,449	107,664
Liabilities	0	0
Foreign currency contracts | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	23,588	0
Liabilities	10,946	36
Level 1 | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	0	0
Level 1 | Interest rate swaps | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	0	0
Level 1 | Commodity contracts | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	0	0
Level 1 | Foreign currency contracts | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	0	0
Level 2 | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	56,258	32,082
Liabilities	139,247	7,923
Level 2 | Interest rate swaps | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	12,080	4,686
Liabilities	128,301	7,887
Level 2 | Commodity contracts | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	20,590	27,396
Liabilities	0	0
Level 2 | Foreign currency contracts | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	23,588	0
Liabilities	10,946	36
Level 3 | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	81,859	80,268
Liabilities	0	0
Level 3 | Interest rate swaps | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	0	0
Level 3 | Commodity contracts | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	81,859	80,268
Liabilities	0	0
Level 3 | Foreign currency contracts | Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	$ 0	$ 0

Fair Value of Financial Instr70

Fair Value of Financial Instruments - Unobservable input reconciliation (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018USD ($)$ / MWh	Jun. 30, 2017USD ($)	Jun. 30, 2018USD ($)$ / MWh	Jun. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning Balance	$ 60,148	$ 87,318	$ 80,268	$ 66,138
Realized and unrealized gains (losses):
Included in other comprehensive income (loss)	9,503	(7,634)	(10,507)	10,628
Included in operating revenues, net	14,016	(741)	15,549	5,424
Settlements	(1,808)	(2,153)	(3,451)	(5,400)
Ending Balance	81,859	$ 76,790	81,859	$ 76,790
Assets	138,117		138,117		$ 112,350
Liabilities	139,247		139,247		$ 7,923
Commodity contracts | Level 3
Realized and unrealized gains (losses):
Assets	81,859		81,859
Liabilities	$ 0		$ 0
Discounted cash flow | Commodity contracts | Minimum | Level 3
Unobservable Inputs
Unobservable input | $ / MWh	11.4		11.4
Discounted cash flow | Commodity contracts | Maximum | Level 3
Unobservable Inputs
Unobservable input | $ / MWh	125.5		125.5
Option model | Commodity contracts | Minimum | Level 3
Unobservable Inputs
Unobservable input	0.030		0.030
Option model | Commodity contracts | Maximum | Level 3
Unobservable Inputs
Unobservable input	0.074		0.074

Stockholders' Equity - Shares O

Stockholders' Equity - Shares Outstanding (Details) - shares	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Common Stock Outstanding [Roll Forward]
Common stock outstanding (in shares)	148,086,027	92,223,089
Shares issued under equity incentive plan (in shares)	0	45,385
Common stock outstanding (in shares)	209,061,636	92,268,474
Class A common stock
Common Stock Outstanding [Roll Forward]
Shares issued under equity incentive plan (in shares)	60,975,609	0

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)	Jun. 11, 2018	Feb. 06, 2018	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Class of Stock [Line Items]
Issuance of Class A common stock to affiliates						$ 650,000,000
Contractual term						10 years
Number of shares available for issuance (in shares)			3,808,697			3,808,697
Stock-based compensation expense			$ 100,000		$ 1,800,000	$ 100,000	$ 3,300,000
Special cash dividend (in dollars per share)			$ 0.19	$ 0.19
Brookfield Asset Management
Class of Stock [Line Items]
Backstop support agreement amount		$ 650,000,000
Backstop support agreement, share price (in dollars per share)		$ 10.66
Share Purchase Agreement
Class of Stock [Line Items]
Issuance of Class A common stock to affiliates (in shares)	60,975,609
Price of shares issued (in dollars per share)	$ 10.66
Issuance of Class A common stock to affiliates	$ 650,000,000
TerraForm Power | Share Purchase Agreement | Affiliates of Brookfield
Class of Stock [Line Items]
Percentage of ownership	65.00%
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Equity instrument granted (in shares)						117,424
Grant-date fair value						$ 1,300,000
Compensation cost, period for recognition						3 years

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock Units (Details) - Restricted Stock Units (RSUs) $ in Millions	6 Months Ended
	Jun. 30, 2018USD ($)shares
Number of RSUs Outstanding
Beginning balance (in shares)	0
Granted (shares)	117,424
Ending balance (in shares)	117,424
Aggregate Intrinsic Value | $	$ 0.2
Weighted Average Remaining Contractual Life (in years)	2 years 9 months

Stockholders' Equity - Dividend

Stockholders' Equity - Dividends (Details) - $ / shares	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018
Equity [Abstract]
Special cash dividend (in dollars per share)	$ 0.19	$ 0.19

(Loss) Earnings Per Share (Deta

(Loss) Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net (loss) income attributable to Class A common stockholders	$ (21,337)	$ 82,796	$ (112,663)	$ (26,300)	$ 9,606	$ (30,797)	$ 61,459	$ (21,191)	$ (47,491)	$ (160,154)	$ (123,511)	$ (78,832)
Less: accretion of redeemable non-controlling interest	0				(2,187)		0	(4,413)
Net (loss) income attributable to Class A common stockholders after accretion of redeemable non-controlling interests	$ (21,337)				$ 7,419		$ 61,459	$ (25,604)
Basic and diluted earnings (loss) per share (in $ per share)		$ 0.56	$ (0.82)	$ (0.31)	$ 0.08	$ (0.36)		$ (0.28)	$ (0.59)	$ (1.61)	$ (1.40)	$ (1.24)
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Contingently issuable shares (in shares)	0						66,000
Additional contingently issuable shares (in shares)	0						29,000
Restricted Stock Units (RSUs)
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Shares excluded from calculation (shares)	117,000							1,524,317
Restricted Stock Units (RSUs)
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Shares considered to be dilutive (in shares)					487,950		15,000
Class A common stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Weighted average basic Class A shares outstanding (in shares)	161,568,000				92,257,000		154,890,000	92,165,000
Weighted average diluted Class A shares outstanding (in shares)	161,568,000				92,745,000		154,905,000	92,165,000
Basic and diluted earnings (loss) per share (in $ per share)	$ (0.13)				$ 0.08		$ 0.40	$ (0.28)

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands

Aug. 03, 2018shares

Jul. 02, 2018USD ($)

Jun. 12, 2018USD ($)

Mar. 06, 2018USD ($)bankdebt_instrument

Jun. 09, 2017USD ($)

May 27, 2016USD ($)employee

Apr. 04, 2016employee

Jan. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Jun. 30, 2018USD ($)

Feb. 07, 2018

Dec. 31, 2016USD ($)

Loss Contingencies [Line Items]

Outstanding letters of credit

$ 156,900

Securities Class Action

Loss Contingencies [Line Items]

Number of defendants | employee

2

Litigation settlement

$ 14,800

$ 1,130

$ 1,130

Portion of settlement covered by insurance providers

$ 13,630

13,630

Loss contingency accrual

$ 1,100

Litigation settlement, escrow deposit

$ 13,600

13,600

Insurance settlements payable

$ 13,600

First Wind Acquisition Claim | SunEdison

Loss Contingencies [Line Items]

Obligated earn-out payments

$ 231,000

Number of employee resignations | employee

2

Revolving Credit Facility | Line of Credit

Loss Contingencies [Line Items]

Outstanding letters of credit

$ 78,800

Director | Securities Class Action

Loss Contingencies [Line Items]

Number of defendants | employee

1

Saeta

Loss Contingencies [Line Items]

Consideration transferred for bank guarantee

$ 1,200,000

Letter of credit facilities | debt_instrument

2

Number of lending banks | bank

2

Consideration transferred

$ 1,120,000

Percentage acquired

95.28%

100.00%

Saeta | Subsequent Event

Loss Contingencies [Line Items]

Consideration transferred

$ 54,600

Percentage acquired

4.72%

Class A common stock | Subsequent Event | Securities Class Action

Loss Contingencies [Line Items]

Issuance of Class A common stock to affiliates (in shares) | shares

80,084

Related Parties - Merger With A

Related Parties - Merger With Affiliate of SunEdison (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 11, 2018	Jun. 30, 2018	Oct. 16, 2017
Related Party Transaction [Line Items]
Issuance of Class A common stock to affiliates		$ 650,000
Class A common stock | Orion US Holdings 1 LP
Related Party Transaction [Line Items]
Ownership percentage			51.00%
Share Purchase Agreement
Related Party Transaction [Line Items]
Issuance of Class A common stock to affiliates (in shares)	60,975,609
Price of shares issued (in dollars per share)	$ 10.66
Issuance of Class A common stock to affiliates	$ 650,000
TerraForm Power | Share Purchase Agreement | Affiliates of Brookfield
Related Party Transaction [Line Items]
Percentage of ownership	65.00%

Related Parties - Other Narrati

Related Parties - Other Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 30, 2018	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	May 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
General and administrative expenses - affiliate		$ 4,023,000	$ 3,282,000	$ 7,497,000	$ 4,701,000
Due from affiliates		1,533,000		1,533,000				$ 4,370,000
Capital contribution				(2,801,000)
Due to affiliates		9,205,000		9,205,000				3,968,000
Cost of operations - affiliate		0	3,427,000	0	9,025,000
Base Management Fee
Related Party Transaction [Line Items]
Due to affiliates		3,700,000		3,700,000			$ 3,200,000	3,400,000
Acquisition-Related Costs Payable
Related Party Transaction [Line Items]
Due to affiliates		3,700,000		3,700,000
Corporate Headquarter Leasehold Improvements
Related Party Transaction [Line Items]
Due to affiliates		1,100,000		1,100,000
Accrued Interest Payable
Related Party Transaction [Line Items]
Due to affiliates		100,000		100,000
Payables to Other Affiliates
Related Party Transaction [Line Items]
Due to affiliates		600,000		600,000
Accrued Standby Fee Interest
Related Party Transaction [Line Items]
Due to affiliates		600,000		600,000				600,000
SunEdison
Related Party Transaction [Line Items]
Cost of operations - affiliate			$ 2,400,000		2,800,000
SunEdison | Incentive Distribution Rights
Related Party Transaction [Line Items]
Payments to affiliate				0	$ 0
Brookfield Asset Management
Related Party Transaction [Line Items]
Due from affiliates, current							$ 3,500,000
Brookfield Asset Management | Management Services Agreement
Related Party Transaction [Line Items]
General and administrative expenses - affiliate		$ 3,700,000		$ 6,900,000
Brookfield Asset Management | Incentive Distribution Rights
Related Party Transaction [Line Items]
Quarterly distribution rights, level one ($ per share)		$ 0.93		$ 0.93
Quarterly distribution rights, level two ($ per share)		$ 1.05		$ 1.05
Brookfield Asset Management | Credit Support
Related Party Transaction [Line Items]
Percentage of savings realized in transaction		50.00%
Cost of operations - affiliate		$ 2,900,000
Brookfield and Affiliates
Related Party Transaction [Line Items]
Lease term						10 years
Revenue from related parties	$ 3,700,000
Capital contribution				$ 3,000,000
TerraForm Global, LLC | Affiliated Entity
Related Party Transaction [Line Items]
Due from affiliates		$ 1,500,000		$ 1,500,000				$ 4,400,000

Related Parties - Historical Su

Related Parties - Historical SunEdison Services (Details) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
Related Party Transaction [Line Items]
Cost of operations - affiliate	$ 0	$ 3,427		$ 0	$ 9,025
Stock-based compensation expense	$ 100	1,800		$ 100	3,300
SunEdison
Related Party Transaction [Line Items]
Cost of operations - affiliate		2,400			2,800
General and administrative expenses - affiliate		3,300			4,700
Stock-based compensation expense		$ 900			$ 1,900
Proceeds from warranty claims			$ 7,000
SunEdison | Chile Facility EPC Contract
Related Party Transaction [Line Items]
Proceeds from warranty claims			$ 4,800

Segment Reporting - Income stat

Segment Reporting - Income statement summary table (Details) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Jun. 30, 2018USD ($)segment	Jun. 30, 2017USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment							3
Segment Reporting Information, Profit (Loss)
Operating revenues, net	$ 179,888				$ 170,367		$ 307,435	$ 321,502
Depreciation, accretion and amortization expense	69,994				63,222		135,584	124,209
Impairment of renewable energy facilities	0				1,429		15,240	1,429
Other operating costs and expenses	82,595				80,169		151,361	158,249
Interest expense (income), net	50,892				68,205		104,446	136,517
Gain on sale of renewable energy facilities	0				(37,116)		0	(37,116)
Other non-operating (income) expenses, net	(415)				(3,431)		1,325	(2,484)
Income tax expense (benefit)	4,434	$ (1,030)	$ (17,385)	$ (1,099)	(588)	$ (569)	3,404	(1,157)	$ (2,256)	$ (19,641)	$ 2,734	$ (12,584)
Net loss	(27,612)	$ (76,313)	(141,804)	$ (36,354)	(1,523)	$ (56,622)	(103,925)	(58,145)	$ (94,499)	(236,303)	$ (243,747)	$ (208,792)
Balance Sheet
Total assets	9,700,825		6,387,021				9,700,825			6,387,021
Segments | Solar
Segment Reporting Information, Profit (Loss)
Operating revenues, net	83,321				101,485		143,044	167,486
Depreciation, accretion and amortization expense	27,141				27,900		54,742	54,675
Impairment of renewable energy facilities	0				1,429		15,240	1,429
Other operating costs and expenses	14,467				16,487		28,683	30,395
Interest expense (income), net	15,734				19,942		30,256	39,523
Gain on sale of renewable energy facilities	0				(37,116)		0	(37,116)
Other non-operating (income) expenses, net	(2,558)				(872)		(2,558)	(914)
Income tax expense (benefit)	0				0		0	0
Net loss	28,537				73,715		16,681	79,494
Balance Sheet
Total assets	2,823,676		2,897,036				2,823,676			2,897,036
Segments | Wind
Segment Reporting Information, Profit (Loss)
Operating revenues, net	75,281				68,882		143,105	154,016
Depreciation, accretion and amortization expense	35,269				34,604		72,934	68,055
Impairment of renewable energy facilities	0				0		0	0
Other operating costs and expenses	32,718				24,781		58,532	49,942
Interest expense (income), net	11,246				21,330		22,015	42,229
Gain on sale of renewable energy facilities	0				0		0	0
Other non-operating (income) expenses, net	32				75		885	623
Income tax expense (benefit)	364				0		364	0
Net loss	(4,348)				(11,908)		(11,625)	(6,833)
Balance Sheet
Total assets	4,250,855		3,400,858				4,250,855			3,400,858
Segments | Regulated Solar and Wind
Segment Reporting Information, Profit (Loss)
Operating revenues, net	21,286						21,286
Depreciation, accretion and amortization expense	7,194						7,194
Impairment of renewable energy facilities	0						0
Other operating costs and expenses	5,041						5,041
Interest expense (income), net	(4,753)						(4,753)
Gain on sale of renewable energy facilities	0						0
Other non-operating (income) expenses, net	110						110
Income tax expense (benefit)	2,174						2,174
Net loss	11,520						11,520
Balance Sheet
Total assets	2,458,868						2,458,868
Corporate
Segment Reporting Information, Profit (Loss)
Operating revenues, net	0				0		0	0
Depreciation, accretion and amortization expense	390				718		714	1,479
Impairment of renewable energy facilities	0				0		0	0
Other operating costs and expenses	30,369				38,901		59,105	77,912
Interest expense (income), net	28,665				26,933		56,928	54,765
Gain on sale of renewable energy facilities	0				0		0	0
Other non-operating (income) expenses, net	2,001				(2,634)		2,888	(2,193)
Income tax expense (benefit)	1,896				(588)		866	(1,157)
Net loss	(63,321)				$ (63,330)		(120,501)	$ (130,806)
Balance Sheet
Total assets	$ 167,426		$ 89,127				$ 167,426			$ 89,127

Accumulated Other Comprehensi81

Accumulated Other Comprehensive Income - Schedule of Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance as of December 31, 2016		$ 2,296,257		$ 2,387,712	$ 2,729,494
Cumulative-effect adjustment net of tax benefit of $1,579	[1]					$ 20,106
Net unrealized gains/losses arising during the period				(6,768)	16,223
Reclassification of net realized loss (gain) into earnings				(923)	14,120
Other comprehensive income (loss), net of tax		7,046	$ 13,995	(7,691)	30,343
Accumulated other comprehensive income		37,400		37,400		48,018
Balance as of June 30, 2017		2,886,698		2,886,698
Foreign Currency Translation Adjustments Attributable to Parent
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance as of December 31, 2016				(13,412)	(22,133)
Cumulative-effect adjustment net of tax benefit of $1,579						0
Net unrealized gains/losses arising during the period				(8,675)	5,601
Reclassification of net realized loss (gain) into earnings				0	14,741
Accumulated other comprehensive income		(22,087)	(1,791)	(22,087)	(1,791)
Balance as of June 30, 2017		(22,087)	(1,074)	(22,087)	(1,074)
Hedging Activities Attributable to Parent
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance as of December 31, 2016				61,430	45,045
Cumulative-effect adjustment net of tax benefit of $1,579						(4,164)
Net unrealized gains/losses arising during the period				1,907	10,622
Reclassification of net realized loss (gain) into earnings				(923)	(621)
Accumulated other comprehensive income		58,250	55,046	58,250	55,046
Balance as of June 30, 2017		59,487	43,207	59,487	43,207
Cumulative effect adjustment, tax						1,579
Accumulated Other Comprehensive Income Attributable to Parent
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balance as of December 31, 2016				48,018	22,912
Cumulative-effect adjustment net of tax benefit of $1,579	[1]					(4,164)
Balance as of June 30, 2017		37,400	42,133	37,400	42,133
Cumulative effect adjustment, tax						$ 1,600
Foreign Currency Translation Adjustments Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income (loss), net of tax				(8,675)	20,342
OCI before reclassifications, tax expense (benefit)				0	0
Reclassification from AOCI, tax expense (benefit)				0	8,858
Hedging Activities Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other comprehensive income (loss), net of tax				984	10,001
OCI before reclassifications, tax expense (benefit)				0	4,480
Reclassification from AOCI, tax expense (benefit)				0	406
Accumulated Other Comprehensive Income Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income		$ 36,163	$ 53,255	36,163	53,255
Foreign Currency Translation Adjustments Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest				0	(717)
Hedging Activities Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest				(1,237)	11,839
AOCI Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest				$ (1,237)	$ 11,122
[1]	See Note 2. Summary of Significant Accounting Policies for discussion regarding the Company’s adoption of Accounting Standards Update (“ASU”) No. 2014-09, ASU No. 2016-08 and ASU No. 2017-12 as of January 1, 2018.

Redeemable Non-controlling In82

Redeemable Non-controlling Interests - Adjustments to Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Deferred income taxes	$ 202,767	$ 23,121	$ 24,972	$ 30,620
Total liabilities	6,727,578	3,934,953	3,964,649	4,810,396
Redeemable non-controlling interests	86,549	27,571	34,660	165,975
Additional paid-in capital	2,468,771	1,847,611	1,872,125
Accumulated deficit	(301,167)	(279,830)	(387,204)	(227,050)
Total TerraForm Power, Inc. stockholders’ equity	2,200,388	1,592,915	1,527,713	1,260,347
Non-controlling interests	686,310		859,999	1,469,147
Total stockholders’ equity	$ 2,886,698	2,296,257	2,387,712	2,729,494
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Deferred income taxes		16,839	18,636	27,723
Total liabilities		3,928,671	3,958,313	4,807,499
Redeemable non-controlling interests		50,760	58,340	180,367
Additional paid-in capital		1,841,692	1,866,206
Accumulated deficit		(290,818)	(398,629)	(234,440)
Total TerraForm Power, Inc. stockholders’ equity		1,576,008	1,510,369	1,252,957
Non-controlling interests				1,465,042
Total stockholders’ equity		2,279,350	2,370,368	2,717,999
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Deferred income taxes		6,282	6,336	2,897
Total liabilities		6,282	6,336	2,897
Redeemable non-controlling interests		(23,189)	(23,680)	(14,392)
Additional paid-in capital		5,919	5,919
Accumulated deficit		10,988	11,425	7,390
Total TerraForm Power, Inc. stockholders’ equity		16,907	17,344	7,390
Non-controlling interests				4,105
Total stockholders’ equity		$ 16,907	$ 17,344	$ 11,495

Redeemable Non-controlling In83

Redeemable Non-controlling Interests - Adjustments to Statement of Operations and Comprehensive Income (Loss) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax expense (benefit)	$ 4,434	$ (1,030)	$ (17,385)	$ (1,099)	$ (588)	$ (569)	$ 3,404	$ (1,157)	$ (2,256)	$ (19,641)	$ 2,734	$ (12,584)
Net loss	(27,612)	(76,313)	(141,804)	(36,354)	(1,523)	(56,622)	(103,925)	(58,145)	(94,499)	(236,303)	(243,747)	(208,792)
Net loss subsequent to IPO and excluding pre-acquisition net loss of renewable energy facilities acquired from SunEdison			(141,804)							(236,303)	(243,747)	(210,402)
Net income attributable to redeemable non-controlling interests	4,680	(2,022)	(8,668)	4,895	6,362	(993)	2,658	5,369	10,264	1,596	6,482	6,003
Net (loss) income attributable to non-controlling interests	(10,955)	(157,087)	(20,473)	(14,949)	(17,491)	(24,832)	(168,042)	(42,323)	(57,272)	(77,745)	(126,718)	(137,573)
Net (loss) income attributable to Class A common stockholders	(21,337)	$ 82,796	$ (112,663)	$ (26,300)	$ 9,606	$ (30,797)	61,459	$ (21,191)	$ (47,491)	$ (160,154)	$ (123,511)	$ (78,832)
Earnings (loss) per share of Class A common stock - Basic and diluted ($ per share)		$ 0.56	$ (0.82)	$ (0.31)	$ 0.08	$ (0.36)		$ (0.28)	$ (0.59)	$ (1.61)	$ (1.40)	$ (1.24)
Total comprehensive (loss) income	(20,566)	$ (91,050)	$ (155,708)	$ (12,387)	$ 12,472	$ (40,274)	(111,616)	$ (27,802)	$ (40,189)	$ (195,897)	$ (242,905)	$ (195,662)
Comprehensive loss subsequent to IPO and excluding pre-acquisition comprehensive income (loss) of renewable energy facilities acquired from SunEdison											(242,905)	(237,288)
Comprehensive loss attributable to non-controlling interests	(6,269)	(160,352)	(34,372)	(1,288)	(6,897)	(18,935)	(166,621)	(25,832)	(27,120)	(61,492)	(119,406)	(142,977)
Comprehensive income (loss) attributable to Class A common stockholders	$ (14,297)	69,302	(121,336)	(11,099)	19,369	(21,339)	$ 55,005	(1,970)	(13,069)	(134,405)	(123,499)	(94,311)
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax expense (benefit)		(976)	(18,098)	(2,633)	(1,431)	(918)		(2,349)	(4,982)	(23,080)	494	(13,241)
Net loss		(76,367)	(141,091)	(34,820)	(680)	(56,273)		(56,953)	(91,773)	(232,864)	(241,507)	(208,135)
Net loss subsequent to IPO and excluding pre-acquisition net loss of renewable energy facilities acquired from SunEdison			(141,091)							(232,864)	(241,507)	(209,745)
Net income attributable to redeemable non-controlling interests		(2,513)	(7,278)	6,803	10,524	835		11,359	18,162	10,884	18,365	8,512
Net (loss) income attributable to non-controlling interests		(157,087)	(20,514)	(15,077)	(18,629)	(25,339)		(43,968)	(59,045)	(79,559)	(130,025)	(138,371)
Net (loss) income attributable to Class A common stockholders		$ 83,233	$ (113,299)	$ (26,546)	$ 7,425	$ (31,769)		$ (24,344)	$ (50,890)	$ (164,189)	$ (129,847)	$ (79,886)
Earnings (loss) per share of Class A common stock - Basic and diluted ($ per share)		$ 0.56	$ (0.82)	$ (0.31)	$ 0.06	$ (0.37)		$ (0.31)	$ (0.62)	$ (1.65)	$ (1.47)	$ (1.25)
Total comprehensive (loss) income		$ (91,104)	$ (154,995)	$ (10,853)	$ 13,315	$ (39,925)		$ (26,610)	$ (37,463)	$ (192,458)	$ (240,665)	$ (195,005)
Comprehensive loss subsequent to IPO and excluding pre-acquisition comprehensive income (loss) of renewable energy facilities acquired from SunEdison											(240,665)	(236,631)
Comprehensive loss attributable to non-controlling interests		(160,843)	(33,023)	492	(3,873)	(17,614)		(21,487)	(20,995)	(54,018)	(110,830)	(141,266)
Comprehensive income (loss) attributable to Class A common stockholders		69,739	(121,972)	(11,345)	17,188	(22,311)		(5,123)	(16,468)	(138,440)	(129,835)	(95,365)
Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax expense (benefit)		(54)	713	1,534	843	349		1,192	2,726	3,439	2,240	657
Net loss		54	(713)	(1,534)	(843)	(349)		(1,192)	(2,726)	(3,439)	(2,240)	(657)
Net loss subsequent to IPO and excluding pre-acquisition net loss of renewable energy facilities acquired from SunEdison			(713)							(3,439)	(2,240)	(657)
Net income attributable to redeemable non-controlling interests		491	(1,390)	(1,908)	(4,162)	(1,828)		(5,990)	(7,898)	(9,288)	(11,883)	(2,509)
Net (loss) income attributable to non-controlling interests		0	41	128	1,138	507		1,645	1,773	1,814	3,307	798
Net (loss) income attributable to Class A common stockholders		$ (437)	$ 636	$ 246	$ 2,181	$ 972		$ 3,153	$ 3,399	$ 4,035	$ 6,336	$ 1,054
Earnings (loss) per share of Class A common stock - Basic and diluted ($ per share)		$ 0	$ 0	$ 0	$ 0.02	$ 0.01		$ 0.03	$ 0.03	$ 0.04	$ 0.07	$ 0.01
Total comprehensive (loss) income		$ 54	$ (713)	$ (1,534)	$ (843)	$ (349)		$ (1,192)	$ (2,726)	$ (3,439)	$ (2,240)	$ (657)
Comprehensive loss subsequent to IPO and excluding pre-acquisition comprehensive income (loss) of renewable energy facilities acquired from SunEdison											(2,240)	(657)
Comprehensive loss attributable to non-controlling interests		491	(1,349)	(1,780)	(3,024)	(1,321)		(4,345)	(6,125)	(7,474)	(8,576)	(1,711)
Comprehensive income (loss) attributable to Class A common stockholders		$ (437)	$ 636	$ 246	$ 2,181	$ 972		$ 3,153	$ 3,399	$ 4,035	$ 6,336	$ 1,054

Redeemable Non-controlling In84

Redeemable Non-controlling Interests - Noncontrolling Interest Activity (Details) - USD ($) $ in Thousands	3 Months Ended						6 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Beginning balance	$ 27,571	$ 34,660				$ 165,975	$ 34,660	$ 165,975	$ 165,975	$ 165,975
Redeemable non-controlling interests acquired in business combination							55,117
Distributions							(1,118)
Net loss	4,680	(2,022)	$ (8,668)	$ 4,895	$ 6,362	$ (993)	2,658	$ 5,369	$ 10,264	1,596	$ 6,482	$ 6,003
Foreign exchange differences							283
Ending balance	$ 86,549	$ 27,571	34,660				$ 86,549			34,660	$ 165,975
ASU 2014-09 and 2016-08
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative-effect adjustment			$ (4,485)							$ (4,485)

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands

Aug. 10, 2018

Aug. 03, 2018

Jun. 09, 2017

Jan. 31, 2018

Jun. 30, 2018

Mar. 31, 2018

Jun. 30, 2017

Jun. 30, 2018

Jun. 30, 2017

Dec. 31, 2017

Jul. 31, 2018

Jul. 02, 2018

Jun. 12, 2018

Feb. 07, 2018

Subsequent Event [Line Items]

Special cash dividend (in dollars per share)

$ 0.19

$ 0.19

Saeta

Subsequent Event [Line Items]

Percentage acquired

95.28%

100.00%

Class A common stock

Subsequent Event [Line Items]

Special cash dividend (in dollars per share)

$ 0.19

$ 0

$ 0.38

$ 0

Securities Class Action

Subsequent Event [Line Items]

Litigation settlement

$ 14,800

$ 1,130

$ 1,130

Portion of settlement covered by insurance providers

$ 13,630

$ 13,630

Subsequent Event

Subsequent Event [Line Items]

Share repurchase program, authorized amount, percentage of common stock outstanding

5.00%

Special cash dividend (in dollars per share)

$ 0.19

Term of agreement

11 years

Subsequent Event | Saeta

Subsequent Event [Line Items]

Percentage acquired

4.72%

Subsequent Event | Securities Class Action | Class A common stock

Subsequent Event [Line Items]

Issuance of Class A common stock to affiliates (in shares)

80,084