TerraForm Power NY (TERP) 10-Q 12 Nov 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-36542
Entity Registrant Name	TerraForm Power, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-4780940
Entity Address, Address Line One	200 Liberty Street,
Entity Address, Address Line Two	14th Floor
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10281
City Area Code	646
Local Phone Number	992-2400
Title of 12(b) Security	Common Stock, Class A, par value $0.01
Trading Symbol	TERP
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		227,044,072
Entity Central Index Key	0001599947
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Statements of Operations - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Operating revenues, net	$ 253,808,000	$ 246,042,000	$ 734,506,000	$ 553,477,000
Operating costs and expenses:
Cost of operations	75,037,000	59,027,000	207,363,000	146,155,000
General and administrative expenses	15,397,000	21,334,000	60,616,000	65,483,000
General and administrative expenses - affiliate	7,764,000	3,432,000	19,087,000	10,929,000
Acquisition costs	963,000	1,655,000	1,438,000	7,612,000
Acquisition costs - affiliate	0	335,000	0	6,965,000
Impairment of renewable energy facilities	0	0	0	15,240,000
Depreciation, accretion and amortization expense	114,282,000	103,593,000	321,605,000	239,177,000
Total operating costs and expenses	213,443,000	189,376,000	610,109,000	491,561,000
Operating income (loss)	40,365,000	56,666,000	124,397,000	61,916,000
Other expenses (income):
Interest expense, net	89,393,000	72,416,000	246,721,000	176,862,000
Loss (gain) on extinguishment of debt, net	1,355,000	0	(4,188,000)	1,480,000
Loss (gain) on foreign currency exchange, net	10,975,000	(3,070,000)	(4,217,000)	(4,257,000)
Other (income) expenses, net	(557,000)	358,000	(1,752,000)	1,390,000
Total other expenses, net	101,166,000	69,704,000	236,564,000	175,475,000
Loss before income tax expense	(60,801,000)	(13,038,000)	(112,167,000)	(113,559,000)
Income tax expense	1,512,000	6,013,000	3,030,000	9,417,000
Net income (loss)	(62,313,000)	(19,051,000)	(115,197,000)	(122,976,000)
Less: Net (loss) income attributable to redeemable non-controlling interests	(7,341,000)	12,443,000	(14,241,000)	15,101,000
Less: Net (loss) income attributable to non-controlling interests	(135,000)	2,096,000	(33,897,000)	(165,946,000)
Net (loss) income attributable to Class A common stockholders	$ (54,837,000)	$ (33,590,000)	$ (67,059,000)	$ 27,869,000
Weighted average number of shares:
Class A common stock - Basic (in shares)	209,155	209,142	209,149	173,173
Class A common stock - Diluted (in shares)	209,155	209,142	209,149	173,186
(Loss) earnings per share:
Class A common stock - Basic and diluted (in dollars per share)	$ (0.26)	$ (0.16)	$ (0.32)	$ 0.16
Distributions declared per share:
Class A common stock (in dollars per share)	$ 0.2014	$ 0.19	$ 0.6042	$ 0.57

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net loss	$ (62,313)	$ (19,051)	$ (115,197)	$ (122,976)
Foreign currency translation adjustments:
Net unrealized gain (loss) arising during the period	6,934	446	15,806	(8,229)
Hedging activities:
Net unrealized (loss) gain arising during the period	(16,653)	10,621	(43,941)	12,528
Reclassification of net realized loss (gain) into earnings	3,389	(5,832)	(2,439)	(6,755)
Other comprehensive (loss) income, net of tax	(6,330)	5,235	(30,574)	(2,456)
Total comprehensive loss	(68,643)	(13,816)	(145,771)	(125,432)
Less comprehensive (loss) income attributable to non-controlling interests:
Net (loss) income attributable to redeemable non-controlling interests	(7,341)	12,443	(14,241)	15,101
Net (loss) income attributable to non-controlling interests	(135)	2,096	(33,897)	(165,946)
Hedging activities	188	(1,801)	920	(3,038)
Comprehensive (loss) income attributable to non-controlling interests	(7,288)	12,738	(47,218)	(153,883)
Comprehensive (loss) income attributable to Class A common stockholders	$ (61,355)	$ (26,554)	$ (98,553)	$ 28,451

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 239,297	$ 248,524
Restricted cash, current	31,140	27,784
Accounts receivable, net	176,883	145,161
Derivative assets, current	28,908	14,371
Prepaid expenses and other current assets	61,642	65,149
Due from affiliates	265	196
Deposit on acquisitions	114,195	0
Total current assets	652,330	501,185
Renewable energy facilities, net, including consolidated variable interest entities of $3,238,298 and $3,064,675 in 2019 and 2018, respectively	6,967,149	6,470,026
Intangible assets, net, including consolidated variable interest entities of $697,744 and $751,377 in 2019 and 2018, respectively	1,957,146	1,996,404
Goodwill	145,616	120,553
Restricted cash	73,794	116,501
Derivative assets	97,096	90,984
Other assets	36,060	34,701
Total assets	9,929,191	9,330,354
Current liabilities:
Current portion of long-term debt, including consolidated variable interest entities of $266,423 and $64,251 in 2019 and 2018, respectively	635,929	464,332
Accounts payable, accrued expenses and other current liabilities	186,170	181,400
Due to affiliates	8,878	6,991
Derivative liabilities, current portion	38,729	35,559
Total current liabilities	869,706	688,282
Long-term debt, less current portion, including consolidated variable interest entities of $640,050 and $885,760 in 2019 and 2018, respectively	5,624,514	5,297,513
Operating lease obligations, less current portion, including consolidated variable interest entities of $141,683 in 2019	255,507
Asset retirement obligations, including consolidated variable interest entities of $118,406 and $86,456 in 2019 and 2018, respectively	286,282	212,657
Derivative liabilities	141,155	93,848
Deferred income taxes	152,948	178,849
Other liabilities	110,651	90,788
Total liabilities	7,440,763	6,561,937
Redeemable non-controlling interests	20,994	33,495
Stockholders’ equity:
Class A common stock, $0.01 par value per share, 1,200,000,000 shares authorized, 209,663,018 and 209,642,140 shares issued in 2019 and 2018, respectively	2,097	2,096
Additional paid-in capital	2,259,812	2,391,435
Accumulated deficit	(426,662)	(359,603)
Accumulated other comprehensive income	8,744	40,238
Treasury stock, 508,033 and 500,420 shares in 2019 and 2018, respectively	(6,815)	(6,712)
Total TerraForm Power, Inc. stockholders’ equity	1,837,176	2,067,454
Non-controlling interests	630,258	667,468
Total stockholders’ equity	2,467,434	2,734,922
Total liabilities, redeemable non-controlling interests and stockholders’ equity	$ 9,929,191	$ 9,330,354

Unaudited Condensed Consolida_4

Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Renewable energy facilities, net	$ 6,967,149	$ 6,470,026
Intangible assets, net	1,957,146	1,996,404
Current portion of long-term debt	635,929	464,332
Long-term debt, less current portion	5,624,514	5,297,513
Operating lease obligations, less current portion	255,507
Asset retirement obligations	$ 286,282	$ 212,657
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)	209,663,018	209,642,140
Treasury stock (in shares)	508,033	500,420
Consolidated Variable Interest Entities
Renewable energy facilities, net	$ 3,238,298	$ 3,064,675
Intangible assets, net	697,744	751,377
Current portion of long-term debt	266,423	64,251
Long-term debt, less current portion	640,050	885,760
Operating lease obligations, less current portion	141,683
Asset retirement obligations	$ 118,406	$ 86,456

Unaudited Condensed Consolida_5

Unaudited Condensed Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Common Stock Held in Treasury	Total - Non-controlling Interests	Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Class A common stockCommon Stock
Balance at beginning of period (in shares) at Dec. 31, 2017							500,000					148,586,000
Beginning balance at Dec. 31, 2017	$ 2,387,712	$ 1,527,713		$ 1,872,125	$ (387,204)	$ 48,018	$ (6,712)	$ 859,999	$ 1,057,301	$ (198,196)	$ 894	$ 1,486
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(74,291)	82,796			82,796			(157,087)		(157,087)
Distributions to Class A common stockholders	(28,008)	(28,008)		(28,008)
Other comprehensive income (loss)	(14,737)	(13,494)				(13,494)		(1,243)			(1,243)
Contributions from non-controlling interests in renewable energy facilities	7,685							7,685	7,685
Distributions to non-controlling interests in renewable energy facilities	(5,204)							(5,204)	(5,204)
Other	2,994	3,494		3,494				(500)		(500)
Balance at end of period (in shares) at Mar. 31, 2018							500,000					148,586,000
Ending balance at Mar. 31, 2018	2,296,257	1,592,915		1,847,611	(279,830)	30,360	$ (6,712)	703,342	1,059,782	(356,091)	(349)	$ 1,486
Balance at beginning of period (in shares) at Dec. 31, 2017							500,000					148,586,000
Beginning balance at Dec. 31, 2017	$ 2,387,712	1,527,713		1,872,125	(387,204)	48,018	$ (6,712)	859,999	1,057,301	(198,196)	894	$ 1,486
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A common stock to affiliates (in shares)	61,056,000
Other comprehensive income (loss)	$ (2,456)
Distributions to non-controlling interests in renewable energy facilities	(1,993)
Balance at end of period (in shares) at Sep. 30, 2018							500,000					209,642,000
Ending balance at Sep. 30, 2018	2,813,088	2,132,675		2,427,612	(334,757)	44,436	$ (6,712)	680,413	1,047,507	(364,950)	(2,144)	$ 2,096
Balance at beginning of period (in shares) at Mar. 31, 2018							500,000					148,586,000
Beginning balance at Mar. 31, 2018	2,296,257	1,592,915		1,847,611	(279,830)	30,360	$ (6,712)	703,342	1,059,782	(356,091)	(349)	$ 1,486
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		649,390								$ 610
Stock-based compensation	73	73		73
Net income (loss)	(32,292)	(21,337)			(21,337)			(10,955)		(10,955)
Distributions to Class A common stockholders	(28,008)	(28,008)		(28,008)
Other comprehensive income (loss)	7,046	7,040				7,040		6			6
Distributions to non-controlling interests in renewable energy facilities	(6,185)							(6,185)	(6,185)
Other	(193)	(295)		(295)				102	102
Balance at end of period (in shares) at Jun. 30, 2018							500,000					209,562,000
Ending balance at Jun. 30, 2018	2,886,698	2,200,388		2,468,771	(301,167)	37,400	$ (6,712)	686,310	1,053,699	(367,046)	(343)	$ 2,096
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A common stock to affiliates (in shares)			80,000
Issuance of Class A common stock to affiliates	881	881		881
Stock-based compensation	88	88		88
Net income (loss)	(31,494)	(33,590)			(33,590)			2,096		2,096
Distributions to Class A common stockholders	(39,609)	(39,609)		(39,609)
Other comprehensive income (loss)	5,235	7,036				7,036		(1,801)			(1,801)
Distributions to non-controlling interests in renewable energy facilities	(6,499)							(6,499)	(6,499)
Other	853	546		546				307	307
Purchase of non-controlling interests in renewable energy facilities	(3,065)	(3,065)		(3,065)
Balance at end of period (in shares) at Sep. 30, 2018							500,000					209,642,000
Ending balance at Sep. 30, 2018	$ 2,813,088	2,132,675		2,427,612	(334,757)	44,436	$ (6,712)	680,413	1,047,507	(364,950)	(2,144)	$ 2,096
Balance at beginning of period (in shares) at Dec. 31, 2018	209,642,140						500,000					209,642,000
Beginning balance at Dec. 31, 2018	$ 2,734,922	2,067,454		2,391,435	(359,603)	40,238	$ (6,712)	667,468	1,040,771	(373,420)	117	$ 2,096
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	160	160		160
Net income (loss)	(26,676)	(8,627)			(8,627)			(18,049)		(18,049)
Distributions to Class A common stockholders	(41,987)	(41,987)		(41,987)
Other comprehensive income (loss)	(7,249)	(7,925)				(7,925)		676			676
Contributions from non-controlling interests in renewable energy facilities	5,562							5,562	5,562
Distributions to non-controlling interests in renewable energy facilities	(5,023)							(5,023)	(5,023)
Purchase of non-controlling interests in renewable energy facilities	(1,080)	(687)		(687)				(393)	(393)
Non-cash redemption of redeemable non-controlling interests	(7,345)	(7,345)		(7,345)
Balance at end of period (in shares) at Mar. 31, 2019							500,000					209,642,000
Ending balance at Mar. 31, 2019	$ 2,651,284	2,001,043		2,341,576	(368,230)	32,313	$ (6,712)	650,241	1,040,917	(391,469)	793	$ 2,096
Balance at beginning of period (in shares) at Dec. 31, 2018	209,642,140						500,000					209,642,000
Beginning balance at Dec. 31, 2018	$ 2,734,922	2,067,454		2,391,435	(359,603)	40,238	$ (6,712)	667,468	1,040,771	(373,420)	117	$ 2,096
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A common stock to affiliates (in shares)	0
Other comprehensive income (loss)	$ (30,574)
Distributions to non-controlling interests in renewable energy facilities	$ (852)
Balance at end of period (in shares) at Sep. 30, 2019	209,663,018						508,000					209,663,000
Ending balance at Sep. 30, 2019	$ 2,467,434	1,837,176		2,259,812	(426,662)	8,744	$ (6,815)	630,258	1,036,538	(407,317)	1,037	$ 2,097
Balance at beginning of period (in shares) at Mar. 31, 2019							500,000					209,642,000
Beginning balance at Mar. 31, 2019	2,651,284	2,001,043		2,341,576	(368,230)	32,313	$ (6,712)	650,241	1,040,917	(391,469)	793	$ 2,096
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	43	43		43
Net income (loss)	(19,308)	(3,595)			(3,595)			(15,713)		(15,713)
Distributions to Class A common stockholders	(41,991)	(41,991)		(41,991)
Other comprehensive income (loss)	(16,995)	(17,051)				(17,051)		56			56
Distributions to non-controlling interests in renewable energy facilities	(4,866)							(4,866)	(4,866)
Balance at end of period (in shares) at Jun. 30, 2019							500,000					209,642,000
Ending balance at Jun. 30, 2019	2,568,167	1,938,449		2,299,628	(371,825)	15,262	$ (6,712)	629,718	1,036,051	(407,182)	849	$ 2,096
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based Compensation (in shares)							(8,000)					21,000
Stock-based compensation	163	163		265			$ (103)					$ 1
Net income (loss)	(54,972)	(54,837)			(54,837)			(135)		(135)
Distributions to Class A common stockholders	(41,991)	(41,991)		(41,991)
Other comprehensive income (loss)	(6,330)	(6,518)				(6,518)		188			188
Distributions to non-controlling interests in renewable energy facilities	(2,538)							(2,538)	(2,538)
Purchase of non-controlling interests in renewable energy facilities	1,910	1,910		1,910
Non-controlling interests acquired in business combination	$ 3,025							3,025	3,025
Balance at end of period (in shares) at Sep. 30, 2019	209,663,018						508,000					209,663,000
Ending balance at Sep. 30, 2019	$ 2,467,434	$ 1,837,176		$ 2,259,812	$ (426,662)	$ 8,744	$ (6,815)	$ 630,258	$ 1,036,538	$ (407,317)	$ 1,037	$ 2,097

Unaudited Condensed Consolida_6

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ (115,197,000)	$ (122,976,000)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, accretion and amortization expense	321,605,000	239,177,000
Amortization of favorable and unfavorable rate revenue contracts, net	28,645,000	29,478,000
(Reductions) charges to allowance for doubtful accounts, net	(3,299,000)	846,000
Impairment of renewable energy facilities	0	15,240,000
Amortization of deferred financing costs, debt premiums and discounts, net	7,720,000	7,969,000
Unrealized loss (gain) on interest rate swaps	23,094,000	(11,688,000)
Unrealized gain on commodity contract derivatives, net	(3,840,000)	(3,845,000)
Recognition of deferred revenue	(1,987,000)	(1,344,000)
Stock-based compensation expense	468,000	161,000
(Gain) loss on extinguishment of debt, net	(4,188,000)	1,480,000
Loss on disposal of renewable energy facilities	13,293,000	6,764,000
Gain on foreign currency exchange, net	(4,649,000)	(9,643,000)
Deferred taxes	139,000	4,888,000
Other, net	(308,000)	(393,000)
Changes in assets and liabilities, excluding the effect of acquisitions:
Accounts receivable	(32,198,000)	(18,758,000)
Prepaid expenses and other current assets	9,278,000	9,154,000
Accounts payable, accrued expenses and other current liabilities	5,238,000	(13,002,000)
Due to affiliates, net	1,818,000	4,158,000
Other, net	22,571,000	13,361,000
Net cash provided by operating activities	268,203,000	151,027,000
Cash flows from investing activities:
Capital expenditures	(16,508,000)	(15,320,000)
Proceeds from energy rebate and reimbursable interconnection costs	5,123,000	8,224,000
Proceeds from the settlement of foreign currency contracts, net	28,063,000	22,429,000
Payments to acquire businesses, net of cash and restricted cash acquired	(617,587,000)	(886,104,000)
Payments to acquire renewable energy facilities from third parties, net of cash and restricted cash acquired	(18,255,000)	(4,105,000)
Payment of deposit on acquisitions	(114,195,000)	0
Other investing activities	2,476,000	0
Net cash used in by investing activities	(730,883,000)	(874,876,000)
Cash flows from financing activities:
Proceeds from issuance of Class A common stock to affiliates	0	650,000,000
Proceeds from the Sponsor Line - affiliate	0	86,000,000
Repayment of the Sponsor Line - affiliate	0	(86,000,000)
Proceeds from Bridge Facility	475,000,000	0
Revolver draws	409,500,000	619,000,000
Revolver repayments	(430,500,000)	(200,466,000)
Term Loan principal payments	(2,625,000)	(2,625,000)
Borrowings of non-recourse long-term debt	312,053,000	236,381,000
Principal payments and prepayments on non-recourse long-term debt	(186,329,000)	(180,124,000)
Debt financing fees paid	(15,972,000)	(7,424,000)
Sale of membership interests and contributions from non-controlling interests in renewable energy facilities	5,562,000	7,685,000
Purchase of membership interests and distributions to non-controlling interests in renewable energy facilities	(17,204,000)	(21,792,000)
Proceeds from affiliates	0	4,803,000
Cash distributions to Class A common stockholders	(125,969,000)	(95,625,000)
Recovery of related party short swing profit	0	2,994,000
Net cash provided by financing activities	423,516,000	1,012,807,000
Net (decrease) increase in cash, cash equivalents and restricted cash	(39,164,000)	288,958,000
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(9,414,000)	(3,750,000)
Cash, cash equivalents and restricted cash at beginning of period	392,809,000	224,787,000
Cash, cash equivalents and restricted cash at end of period	344,231,000	509,995,000
Supplemental Disclosures:
Cash paid for interest	211,517,000	170,549,000
Cash paid for income taxes	$ 4,152,000	$ 667,000

Nature of Operations and Organi

Nature of Operations and Organization	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations and Organization	NATURE OF OPERATIONS AND ORGANIZATION TerraForm Power, Inc. (“TerraForm Power” and, together with its subsidiaries, the “Company”) is a holding company and its primary asset is an equity interest in TerraForm Power, LLC (“Terra LLC”). TerraForm Power is the managing member of Terra LLC and operates, controls and consolidates the business affairs of 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. The Company is sponsored by Brookfield Asset Management Inc. (“Brookfield”) and its primary business strategy is to acquire operating solar and wind assets in North America and Western Europe. As of September 30, 2019 , affiliates of Brookfield held approximately 65% of TerraForm Power’s Class A common stock (“Common Stock”). As discussed in Note 21. Subsequent Events , on October 8, 2019, the Company completed a public offering and a private placement of its Common Stock whereby the combined ownership of affiliates of Brookfield became approximately 61% as of the date of the issuance of this Quarterly Report.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Principles of Consolidation 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. Certain prior period amounts in the condensed consolidated financial statements and accompanying notes have been reclassified to conform to the current period’s presentation. 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 audited consolidated financial statements for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 15, 2019. Interim results are not necessarily indicative of results for a full year or any subsequent interim period. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all material adjustments consisting of a normal and recurring nature necessary to present fairly the Company’s financial position as of September 30, 2019 , results of operations, comprehensive income (loss) for the three and nine months ended September 30, 2019 and 2018 and cash flows for the nine months ended September 30, 2019 and 2018 . Use of Estimates In preparing the unaudited condensed consolidated financial statements, the Company uses 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 2019 In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842), which primarily changes the lessee’s accounting for operating leases by requiring the recognition of lease right-of-use assets and lease liabilities. The guidance also eliminates previous real estate specific provisions. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842), Targeted Improvements, which amended the standard to give entities another option to apply the requirements of the standard in the period of adoption (January 1, 2019) or Effective Date Method. The Company adopted the new accounting guidance on January 1, 2019 using a modified retrospective approach reflecting the Effective Date Method of adoption in which the Company continued to apply the guidance in ASC 840, Leases to the comparable periods presented in the year of adoption. The Company made the following elections provided under the standard: • The package of practical expedients that permits the Company to retain its existing lease assessment and classification; • The practical expedient that allows the Company to not evaluate existing and expired land easements; • The practical expedient to not separate non-lease components in power purchase agreements (“PPAs”) in which the Company is the lessor in providing energy, capacity, and incentive products for a bundled fixed rate; and • The Company elected not to apply the recognition requirements for short-term operating leases, defined as a term of twelve months or shorter, from the commencement date. The Company evaluated the impact of Topic 842 as it relates to operating leases for land, buildings and equipment for which it is the lessee and reviewed its existing contracts for embedded leases. The adoption of the new standard resulted in the recognition of right-of-use assets and lease liabilities of approximately $252.7 million and $245.3 million , respectively, as of January 1, 2019 for operating leases, whereas the Company’s accounting for finance leases remained substantially unchanged. See Note 7. Leases for additional details. A significant portion of the Company’s operating revenues are generated from delivering electricity and related products from owned solar and wind renewable energy facilities under PPAs in which the Company is the lessor. Revenue is recognized when electricity is delivered and is accounted for as rental income under the lease standard. The adoption of ASC 842 did not have an impact on the accounting policy for rental income from the Company’s PPAs in which it is the lessor. The Company elected the package of practical expedients available under ASC 842, which did not require the Company to reassess its lease classification from ASC 840. Additionally, the Company elected the practical expedient to not separate lease and non-lease components for lessors. This election allows energy (lease component) and environmental incentives or renewable energy certificates (non-lease components) under bundled PPAs to be accounted as a singular lease unit of account under ASC 842. In October 2018, the FASB issued ASU No. 2018-16, Derivatives and Hedging (Topic 815): Inclusion of the Secured Overnight Financing Rate (“SOFR”) Overnight Index Swap (“OIS”) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes. This ASU expands the list of United States (“U.S.”) benchmark interest rates permitted in the application of hedge accounting by adding the SOFR as a permissible U.S. benchmark rate. The Company does not have any derivative instruments indexed to SOFR as a benchmark interest rate, accordingly, the adoption of ASU No. 2018-16 as of January 1, 2019 did not have an impact on the Company’s consolidated financial statements. Recently Issued Accounting Standards Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), to provide financial statement users with more useful information about expected credit losses. This ASU changes how entities measure credit losses on financial instruments and the timing of when such losses are recognized. The guidance is effective for fiscal years and interim periods within those years beginning after January 1, 2020, with early adoption permitted for periods beginning after December 15, 2018. The Company is currently evaluating the impact of this guidance on its consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. This ASU removes some disclosure requirements, modifies others, and adds some new disclosure requirements. The guidance is effective January 1, 2020, with early adoption permitted. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40) Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. This ASU amends the definition of a hosting arrangement and requires a customer in a cloud computing arrangement that is a service contract to follow the internal use software guidance in ASC 350-402 to determine which implementation costs to capitalize as assets. Capitalized implementation costs are amortized over the term of the hosting arrangement, beginning when the module or component of the hosting arrangement is ready for its intended use. The guidance is effective January 1, 2020, with early adoption permitted. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities. The amendments in this ASU require reporting entities to consider indirect interests held through related parties under common control for determining whether fees paid to decision makers and service provider are variable interests. These indirect interests should be considered on a proportional basis rather than as the equivalent of a direct interest in its entirety (as currently required in U.S. GAAP). The guidance is effective January 1, 2020, with early adoption permitted. Entities are required to apply the amendments in this guidance retrospectively with a cumulative-effect adjustment to retained earnings at the beginning of the earliest period presented. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenue	REVENUE The following table presents the Company’s operating revenues, net and disaggregated by revenue source: Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 (In thousands) Solar Wind Regulated Solar and Wind Total Solar Wind Regulated Solar and Wind Total PPA rental income $ 73,425 $ 31,532 $ — $ 104,957 $ 66,982 $ 35,084 $ — $ 102,066 Commodity derivatives — 10,453 — 10,453 — 7,469 — 7,469 PPA and market energy revenue 10,104 17,861 28,807 56,772 14,353 18,846 32,594 65,793 Capacity revenue from remuneration programs 1 — — 54,772 54,772 — — 47,356 47,356 Amortization of favorable and unfavorable rate revenue contracts, net (2,017 ) (7,774 ) — (9,791 ) (2,132 ) (7,779 ) — (9,911 ) Energy revenue 81,512 52,072 83,579 217,163 79,203 53,620 79,950 212,773 Incentive revenue 20,142 2,435 14,068 36,645 15,680 3,343 14,246 33,269 Operating revenues, net $ 101,654 $ 54,507 $ 97,647 $ 253,808 $ 94,883 $ 56,963 $ 94,196 $ 246,042 Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 (In thousands) Solar Wind Regulated Solar and Wind Total Solar Wind Regulated Solar and Wind Total PPA rental income $ 167,397 $ 135,670 $ — $ 303,067 $ 159,116 $ 138,396 $ — $ 297,512 Commodity derivatives — 42,560 — 42,560 — 39,917 — 39,917 PPA and market energy revenue 24,461 62,583 79,716 166,760 34,318 31,897 38,909 105,124 Capacity revenue from remuneration programs 1 — — 154,913 154,913 — — 59,327 59,327 Amortization of favorable and unfavorable rate revenue contracts, net (5,330 ) (23,315 ) — (28,645 ) (6,075 ) (23,403 ) — (29,478 ) Energy revenue 186,528 217,498 234,629 638,655 187,359 186,807 98,236 472,402 Incentive revenue 55,065 6,484 34,302 95,851 50,568 13,261 17,246 81,075 Operating revenues, net $ 241,593 $ 223,982 $ 268,931 $ 734,506 $ 237,927 $ 200,068 $ 115,482 $ 553,477 ——— (1) Represents the remuneration related on the Company’s investments in renewable energy facilities in Spain. Contract balances and performance obligations As of September 30, 2019 and December 31, 2018, other liabilities in the unaudited condensed consolidated balance sheets included deferred revenue comprising of $8.5 million and $8.8 million , respectively, which primarily consisted of upfront government incentives, and contract liabilities of $3.2 million and $4.9 million , respectively, related to performance obligations that have not yet been satisfied. These contract liabilities represented advanced customer receipts primarily related to future renewable energy credits (“REC”) deliveries that are recognized into revenue under Topic 606. The amount of revenue recognized during the three and nine months ended September 30, 2019 related to contract liabilities was $0.4 million and $1.7 million , respectively.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS 2019 Acquisitions (i) WGL Acquisition On September 26, 2019, TerraForm Arcadia Holdings, LLC, a Delaware limited liability company and a wholly-owned subsidiary of the Company (“TerraForm Arcadia”), completed the acquisition of an approximately 320 megawatt (“MW”) distributed generation portfolio of renewable energy facilities in the United States from subsidiaries of AltaGas Ltd., a Canadian corporation (“AltaGas”), for a purchase price of $720.0 million , plus $15.1 million for working capital. The acquisition was pursuant to a membership interest purchase agreement (the “Purchase Agreement”) dated July 19, 2019, entered into by TerraForm Arcadia, WGL Energy Systems, Inc., a Delaware corporation (“WGL”), and WGSW, Inc., a Delaware corporation (“WGSW”, and together with WGL, the “Sellers”), both subsidiaries of AltaGas (the “WGL Acquisition”). Pursuant to the Purchase Agreement, the ownership of certain projects for which the Sellers have not yet received the required third party consents or have not completed construction (the “Delayed Projects”) will be transferred to the Company once such third party consents are received or construction is completed, subject to certain terms and conditions. The Delayed Projects represent 34.8 MW of the combined nameplate capacity of the acquired renewable energy facilities. The purchase price allocated to the Delayed Projects based on the Purchase Agreement was $114.2 million and is presented as Deposit on acquisitions in the unaudited condensed consolidated balance sheets. In the event that the title to certain Delayed Projects is not transferred to the Company within a certain period of time, the Company is entitled to a full refund of the value of these projects based on the Purchase Agreement. As discussed in Note 21. Subsequent Events , the title to 43 Delayed Projects with a purchase value of approximately $68.8 million and a combined nameplate capacity of 18.0 MW was transferred to the Company on October 31, 2019. The remaining balance of the Delayed Projects as of the date of this Quarterly Report was approximately $45.4 million . The Company funded the purchase price and the related initial costs of the WGL Acquisition with the net proceeds of $475.0 million Bridge Facility and the remainder from draws on the Revolver. See Note 10. Long-Term Debt for definitions and additional details. The Company accounted for the WGL Acquisition under the acquisition method of accounting for business combinations. The final accounting for the WGL Acquisition has not been completed since the evaluation necessary to assess the fair values of acquired assets and assumed liabilities is still in process. The additional information needed by the Company to finalize the measurement of these provisional amounts include the completion of the transfer of the Delayed Projects and the assessment of the incremental borrowing rate for operating leases. The provisional amounts for this business combination 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 September 30, 2019 were as follows: (In thousands) As of September 26, 2019 Renewable energy facilities in service 1 $ 545,085 Intangible assets 128,725 Accounts receivable 6,886 Prepaid expenses and other assets 7,978 Total assets acquired 688,674 Accounts payable, accrued expenses and other current liabilities 4,671 Asset retirement obligations 35,740 Operating lease liabilities 20,644 Other liabilities 7,007 Total liabilities assumed 68,062 Non-controlling interests 2 3,025 Purchase price, net of cash and restricted cash acquired 3 617,587 Deposit on acquisitions 114,195 Total cash paid for the WGL Acquisition, net of cash acquired $ 731,782 ——— (1) Includes $23.3 million operating lease right-of-use assets. (2) The fair value of the non-controlling interests was determined using an income approach representing the best indicator of fair value and was supported by a discounted cash flow technique. (3) The Company acquired cash and cash equivalents of $3.4 million as of the acquisition date. The acquired non-financial assets primarily represent an estimate of the fair value of the acquired renewable energy facilities and intangible assets from PPAs 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 13. Fair Value of Financial Instruments . Refer below for additional disclosures related to the acquired finite-lived intangible assets. Intangibles at Acquisition Date The following table summarizes the estimated fair values and the weighted average amortization periods of the acquired intangible assets and assumed intangible liabilities as of the acquisition date. The Company attributed the intangible asset values to favorable rate revenue contracts and PPAs in-place from renewable energy facilities and the intangible liabilities to unfavorable rate revenue contracts. WGL Acquisition Fair Value Weighted Average Amortization Period 1 Favorable rate revenue contracts $ 23,575 16 years In-place value of market rate revenue contracts 105,150 15 years Unfavorable rate revenue contracts 7,007 2 years ——— (1) For the purposes of this disclosure, the weighted average amortization periods are determined based on a weighting of the individual intangible fair values against the total fair value for each major intangible asset class. Unaudited Pro Forma Supplementary Data The unaudited pro forma supplementary data presented in the table below gives effect to the WGL Acquisition, as if the transaction had occurred on January 1, 2018. The pro forma net loss includes interest expense related to incremental borrowings used to finance the transaction and adjustments to depreciation, accretion and amortization expense for the valuation of renewable energy facilities and intangible assets, and excludes the impact of acquisition 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. Nine Months Ended September 30, (In thousands) 2019 2018 Total operating revenues, net $ 790,403 $ 559,523 Net loss (71,099 ) 31,985 (ii) Acquisition of 10.6 MW Distributed Generation Assets During the nine months ended September 30, 2019 , the Company acquired three distributed generation facilities located in the U.S. with a combined nameplate capacity of 10.6 MW from third parties for a purchase price of $18.3 million , net of cash acquired. The facilities are contracted under long-term PPAs with municipal offtakers. This transaction was accounted for as an acquisition of assets. As part of this acquisition, the Company is committed to purchase an additional facility with a nameplate capacity of 4.5 MW for a purchase price of $6.0 million , which is expected to be completed in December 2019. 2018 Acquisitions (i) Saeta Acquisition 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 Yield S.A.U. (“Saeta”), a Spanish renewable power company with then 1,028 MW of wind and solar facilities (approximately 250 MW of solar and 778 MW of wind) 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 the assumption of $1.91 billion of project-level debt. Having acquired 95.28% of the shares of Saeta, the Company then pursued a statutory squeeze out procedure under Spanish law to procure the remaining 4.72% of the shares of Saeta on July 2, 2018 for $54.6 million . The Company funded the $1.12 billion purchase price of the Tendered Shares with $650.0 million of proceeds from a private placement of Common Stock to Orion Holdings and BBHC Orion Holdco L.P. (both affiliates of Brookfield), along with approximately $471.0 million from its existing liquidity, including (i) the proceeds of a $30.0 million draw on its Sponsor Line (as defined in Note 17. Related Parties ), (ii) $359.0 million as part of a draw on the Company’s Revolver (as defined in Note 10. Long-term Debt ), and (iii) approximately $82.0 million of cash on hand. The Company funded the purchase of the remaining 4.72% non-controlling interest in Saeta using $54.6 million of the total proceeds from an additional draw on the Sponsor Line. The Company accounted for the acquisition of Saeta under the acquisition method of accounting for business combinations. The purchase accounting for the Saeta acquisition, including assignment of goodwill to reporting units, was finalized as of June 30, 2019. The final allocation of the acquisition-date fair values of assets, liabilities and redeemable non-controlling interests pertaining to this business combination as of June 30, 2019, was as follows: (In thousands) As of June 12, 2018, reported at December 31, 2018 Adjustments As of June 12, 2018, reported at June 30, 2019 Renewable energy facilities in service $ 1,993,520 $ (6,238 ) $ 1,987,282 Accounts receivable 91,343 — 91,343 Intangible Assets 1,034,176 (31,862 ) 1,002,314 Goodwill 123,106 32,283 155,389 Other assets 43,402 2,845 46,247 Total assets acquired 3,285,547 (2,972 ) 3,282,575 Accounts payable, accrued expenses and other current liabilities 93,032 (1,761 ) 91,271 Long-term debt, including current portion 1,906,831 16,139 1,922,970 Deferred income taxes 171,373 (17,256 ) 154,117 Asset retirement obligations 67,706 (94 ) 67,612 Derivative liabilities 137,002 — 137,002 Other long-term liabilities 23,002 — 23,002 Total liabilities assumed 2,398,946 (2,972 ) 2,395,974 Redeemable non-controlling interests 55,117 — 55,117 Purchase price, net of cash acquired $ 831,484 $ — $ 831,484 ——— (1) The excess purchase price over the estimated fair value of net assets acquired of $155.4 million was recorded as goodwill, with $117.4 million assigned to the Regulated Solar and Wind segment and $38.0 million assigned to the Wind segment. See Note 18. Segment Reporting for additional details on the Company’s segments. (2) The fair value of the non-controlling interests 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 was 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 represented the fair value of acquired renewable energy facilities and intangible assets from concession and licensing contracts 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 were not observable in the market and thus represent Level 3 measurements (as defined in Note 13. Fair Value of Financial Instruments ). Refer below for additional disclosures related to the acquired finite-lived intangible assets. The results of operations of Saeta are included in the Company’s consolidated results since the date of acquisition. The operating revenues and net income of Saeta reflected in the unaudited condensed consolidated statements of operations were $113.1 million and $7.6 million , respectively, for the three months ended September 30, 2019 , and $318.4 million and $33.7 million , respectively, for the nine months ended September 30, 2019 . 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, 2018. 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 nine months ended September 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. (In thousands) Nine Months Ended September 30, 2018 Total operating revenues, net $ 740,066 Net loss (108,314 ) Intangibles at Acquisition Date The following table summarizes the estimated fair value and weighted average amortization period of the acquired intangible assets as of the acquisition date for Saeta. The Company attributed intangible asset value to concessions and licensing agreements in-place from solar and wind facilities. These intangible assets are amortized on a straight-line basis over the estimated remaining useful lives of the facilities from the Company’s acquisition date. As of June 12, 2018 Fair Value (In thousands) Weighted Average Amortization Period 1 Intangible assets - concession and licensing contracts $ 1,034,176 15 years ——— (1) For the 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. (ii) Acquisition of 6.1 MW Distributed Generation Portfolio During the nine months ended September 30, 2018, the Company acquired six distributed generation facilities located in the U.S. with a combined nameplate capacity of 6.1 MW from third parties for a purchase price of $4.1 million , net of cash acquired. The facilities are contracted under long-term PPAs with municipal offtakers. This transaction was accounted for as an acquisition of assets. Acquisition Costs Acquisition costs, which primarily consisted of professional fees for banking, legal and accounting services, were $1.0 million for the three months ended September 30, 2019, compared to $1.7 million in the same period in 2018, and $1.4 million for the nine months ended September 30, 2019, compared to $7.6 million in the same period in 2018. Acquisition costs related to affiliates for the three and nine months ended September 30, 2018 were $0.3 million and $7.0 million , respectively, and are reflected within Acquisition costs - affiliates in the unaudited consolidated condensed statements of operations. No acquisition costs related to affiliates were incurred for the three and nine months ended September 30, 2019.

Cash and Cash Equivalents

Cash and Cash Equivalents	9 Months Ended
	Sep. 30, 2019
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents	CASH AND CASH EQUIVALENTS Cash and cash equivalents include all cash balances and money market funds with original maturity periods of three months or less when purchased. As of September 30, 2019 and December 31, 2018 , cash and cash equivalents included $188.4 million and $177.6 million , respectively, of unrestricted cash held at project-level subsidiaries, which was available for project expenses but not available for corporate use. Restricted Cash 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 certain of the Company’s subsidiaries 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 date of the financial statements. Restricted cash that is not expected to become unrestricted within twelve months from the date of the balance sheet is presented within non-current assets in the consolidated balance sheets. Reconciliation of Cash and Cash Equivalents 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 nine months ended September 30, 2019 : (In thousands) September 30, December 31, Cash and cash equivalents $ 239,297 $ 248,524 Restricted cash - current 31,140 27,784 Restricted cash - non-current 73,794 116,501 Cash, cash equivalents and restricted cash shown in the unaudited condensed consolidated statement of cash flows $ 344,231 $ 392,809 As discussed in Note 10. Long-term Debt , the Company was in default under certain of its non-recourse financing agreements as of the date of the issuance of the financial statements for the nine months ended September 30, 2019 , and for the year ended December 31, 2018 . As a result, the Company reclassified $11.2 million of non-current restricted cash to current as of September 30, 2019 and December 31, 2018 , 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 September 30, 2019 and December 31, 2018 , $2.2 million and $1.4 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 agreements that existed as of the respective balance sheet date.

Renewable Energy Facilities

Renewable Energy Facilities	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Renewable Energy Facilities	RENEWABLE ENERGY FACILITIES Renewable energy facilities, net consisted of the following: (In thousands) September 30, December 31, Renewable energy facilities in service, at cost 1 $ 8,037,096 $ 7,298,371 Less: accumulated depreciation (1,080,363 ) (833,844 ) Renewable energy facilities in service, net 6,956,733 6,464,527 Construction in progress - renewable energy facilities 10,416 5,499 Total renewable energy facilities, net $ 6,967,149 $ 6,470,026 ——— (1) As discussed in Note 2. Summary of Significant Accounting Policies and Note 7. Leases , on January 1, 2019, the Company recognized $252.7 million right-of-use of assets related to operating leases as a result of the adoption of Topic 842, which is included within renewable energy facilities. The amount of right-of-use of assets as of September 30, 2019, including the effect of acquisitions, was $269.3 million . Depreciation expense related to renewable energy facilities was $84.1 million and $240.0 million for the three and nine months ended September 30, 2019 , respectively, compared to $79.2 million and $194.2 million for the same periods in the prior year. 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 had a REC sales agreement with a customer expiring December 31, 2021 that was significant to a certain operating project within a distributed generation portfolio and, on March 31, 2018, this customer filed for protection under Chapter 11 of the U.S. Bankruptcy Code. The Company’s analysis indicated that the bankruptcy filing was a triggering event to perform an impairment evaluation 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 statements of operations for the nine months ended September 30, 2018 . The Company used an income approach methodology of valuation to determine the 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 losses were recognized for the three or nine months ended September 30, 2019.

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	LEASES The Company has operating leases for renewable energy production facilities, land, office space, transmission lines, vehicles and other operating equipment. Leases with an initial term of twelve months or shorter are not recorded on the balance sheet, but are expensed on a straight-line basis over the lease term. During the three and nine months ended September 30, 2019 , the Company did not have any leases with an initial term of less than twelve months. Operating lease right-of-use assets are included within renewable energy facilities, net, whereas right-of-use liabilities are included within accounts payable, accrued expenses and other current liabilities. Right-of-use assets represent the right to use an underlying asset for the lease term and lease liabilities represent the obligation to make lease payments arising from the lease. Operating lease right-of-use assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As the Company’s leases do not provide an implicit rate, the Company calculated an incremental borrowing rate by leveraging external transactions at comparable entities and internally available information to determine the present value of lease payments. The Company’s leases have remaining lease terms ranging from 5 to 41 years. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise any such options. Lease expense is recognized on a straight-line basis over the expected lease term. Although some of the Company’s leases contain lease and non-lease components, the Company applies the practical expedient to account for each lease component and non-lease component as a single lease component. Lease payments include fixed rent and taxes, where applicable, and exclude variable rental payments that include other operating expenses is recognized as incurred. The Company’s lease agreements do not contain any material residual value guarantees or material restrictive covenants. The following tables outline the different components of operating leases and other terms and conditions of the lease agreements where the Company is the lessee. See Note 10. Long-term Debt for more details. The components of lease expense were as follows: (In thousands) Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Fixed operating lease cost $ 4,740 $ 15,936 Variable operating lease cost 1 834 3,239 Total operating lease cost $ 5,574 $ 19,175 ——— (1) Primarily related to production-based variable inputs and adjustments for inflation. Supplemental cash flow information related to the Company’s leases was as follows: (In thousands) Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases 1 $ 5,472 $ 11,487 ——— (1) Right-of-use assets, excluding the effect of acquisitions, obtained in exchange for lease obligations for the nine months ended September 30, 2019 , were not material. Supplemental balance sheet information related to the Company’s leases was as follows: (In thousands, except lease term and discount rate) As of September 30, 2019 Operating leases: Right-of-use assets $ 269,309 Accounts payable, accrued expenses and other current liabilities $ 14,980 Operating lease obligations, less current portion 255,507 Total operating lease liabilities $ 270,487 Weighted Average Remaining Lease Term: Operating leases 18 years Weighted Average Discount Rate: Operating leases 4.5% The maturities of the Company’s operating lease liabilities by fiscal year were as follows: (In thousands) Remainder of 2019 $ 10,417 2020 21,280 2021 21,566 2022 21,434 2023 22,073 Thereafter 324,230 Total lease payments 421,000 Less: Imputed interest (150,513 ) Total $ 270,487 The operating revenues from delivering electricity and the related products from owned solar and wind renewable energy facilities under PPAs in which the Company is the lessor, the majority of which is variable in nature, is recognized when electricity is delivered and is accounted for as rental income under the lease standard. The Company determines if an arrangement is a lease at contract inception, and if so, includes both lease and non-lease components as a single component and accounts for it as a lease. The Company’s PPAs do not contain any residual value guarantees or material restrictive covenants. See Note 3. Revenue for additional details.

Intangible Assets, Net and Good

Intangible Assets, Net and Goodwill	9 Months Ended
	Sep. 30, 2019
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 September 30, 2019 : (In thousands, except weighted average amortization period) Weighted Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Book Value Concession and licensing contracts 14 years $ 948,740 $ (83,182 ) $ 865,558 Favorable rate revenue contracts 13 years 746,126 (184,983 ) 561,143 In-place value of market rate revenue contracts 17 years 651,239 (120,794 ) 530,445 Total intangible assets, net $ 2,346,105 $ (388,959 ) $ 1,957,146 Unfavorable rate revenue contracts 6 years $ 47,777 $ (30,304 ) $ 17,473 Unfavorable rate operations and maintenance contracts 3 months 5,000 (4,770 ) 230 Total intangible liabilities, net 1 $ 52,777 $ (35,074 ) $ 17,703 ——— (1) The Company’s intangible liabilities are classified within other long-term liabilities in the unaudited condensed consolidated balance sheets. The following table presents the gross carrying amount, accumulated amortization and net book value of intangibles as of December 31, 2018 : (In thousands, except weighted average amortization period) Weighted Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Book Value Concession and licensing contracts 15 years $ 1,015,824 $ (36,374 ) $ 979,450 Favorable rate revenue contracts 14 years 738,488 (166,507 ) 571,981 In-place value of market rate revenue contracts 18 years 532,844 (100,543 ) 432,301 Favorable rate land leases 1 16 years 15,800 (3,128 ) 12,672 Total intangible assets, net $ 2,302,956 $ (306,552 ) $ 1,996,404 Unfavorable rate revenue contracts 6 years $ 58,508 $ (41,605 ) $ 16,903 Unfavorable rate operations and maintenance contracts 1 year 5,000 (3,802 ) 1,198 Unfavorable rate land lease 1 14 years 1,000 (218 ) 782 Total intangible liabilities, net 2 $ 64,508 $ (45,625 ) $ 18,883 ——— (1) On January 1, 2019, these amounts were reclassified to right-of-use assets in connection with the adoption of Topic 842. See Note 2. Summary of Significant Accounting Policies and Note 7. Leases for additional details. (2) The Company’s intangible liabilities are classified within other long-term liabilities in the unaudited condensed consolidated balance sheets. 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 nine months ended September 30, 2019 , amortization expense related to concessions and licensing contacts was $16.9 million and $50.1 million , respectively. During the three and nine months ended September 30, 2018 , amortization expense related to concessions and licensing contracts was $13.8 million and $16.7 million , respectively. 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 nine months ended September 30, 2019 , net amortization expense related to favorable and unfavorable rate revenue contracts resulted in a reduction of operating revenues, net of $9.8 million and $28.6 million , respectively, compared to a $9.9 million and $29.5 million reduction of operating revenues, net for the same periods in 2018. 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 nine months ended September 30, 2019 , amortization expense related to the in-place value of market rate revenue contracts was $6.8 million and $19.7 million , respectively, compared to $4.7 million and $21.6 million for the same periods in the prior year. Goodwill Goodwill represents the excess of the consideration transferred and fair value of the non-controlling interests over the fair values of assets acquired and liabilities assumed from business combinations, and reflects the future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. The goodwill balance is not deductible for income tax purposes. The following table presents the activity of the goodwill balance for the nine months ended September 30, 2019 and the year ended December 31, 2018: (In thousands) September 30, December 31, Beginning balance $ 120,553 $ — Goodwill resulting from business combinations 1 — 115,381 Adjustments during the period 2 32,283 7,726 Foreign exchange differences (7,220 ) (2,554 ) Ending balance $ 145,616 $ 120,553 ——— (1) Represents the excess purchase price over the estimated fair value of net assets acquired from Saeta and is primarily attributable to deferred tax liabilities and adjustment to the fair value of certain project long-term debt. See Note 4. Acquisitions for additional details. (2) Represents the adjustments to the goodwill balance arising from the revision of the provisional accounting of Saeta’s purchase price allocation. See Note 4. Acquisitions for discussion of goodwill related to the Saeta acquisition.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES The Company assesses entities for consolidation in accordance with ASC 810. The Company consolidates variable interest entities (“VIEs”) in renewable energy facilities when the Company is determined to be the primary beneficiary. VIEs are entities that lack one or more of the characteristics of a voting interest entity (“VOE”). The Company has a controlling financial interest in a VIE when its variable interest(s) provide it with (i) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (ii) the obligation to absorb losses of the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. 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. VOEs are entities in which (i) the total equity investment at risk is sufficient to enable the entity to finance its activities independently and (ii) the equity holders have the power to direct the activities of the entity that most significantly impact its economic performance, the obligation to absorb the losses of the entity and the right to receive the residual returns of the entity. The usual condition for a controlling financial interest in a voting interest entity is ownership of a majority voting interest. If the Company has a majority voting interest in a voting interest entity, the entity is consolidated. For consolidated VIEs, the Company presented on its consolidated balance sheets, to the extent material, the assets of its consolidated VIEs that can only be used to settle specific obligations of the consolidated VIE, and the liabilities of its consolidated VIEs for which creditors do not have recourse to the Company’s general assets outside of the VIE. The carrying amounts and classification of the consolidated assets and liabilities of the VIEs included in the Company’s unaudited condensed consolidated balance sheets were as follows: (In thousands) September 30, December 31, Current assets $ 134,551 $ 134,057 Non-current assets 4,032,239 3,909,549 Total assets $ 4,166,790 $ 4,043,606 Current liabilities $ 319,738 $ 120,790 Non-current liabilities 949,812 1,014,789 Total liabilities $ 1,269,550 $ 1,135,579 The amounts shown in the table above exclude intercompany balances that were eliminated upon consolidation. All of the assets in the table above are restricted for the settlement of the VIE obligations and all the liabilities in the table above can only be settled by using VIE resources.

Long-term Debt

Long-term Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Long-term Debt	LONG-TERM DEBT Long-term debt consists of the following: (In thousands, except interest rates) September 30, December 31, Interest Type Interest Rate (%) 1 Financing Type Corporate-level long-term debt 2 : Senior Notes due 2023 $ 500,000 $ 500,000 Fixed 4.25 Senior notes Senior Notes due 2025 3 300,000 300,000 Fixed 6.63 Senior notes Senior Notes due 2028 700,000 700,000 Fixed 5.00 Senior notes Revolver 4 356,000 377,000 Variable 4.27 Revolving loan Term Loan 3,5 343,875 346,500 Variable 4.04 Term debt Non-recourse long-term debt: Permanent financing 3,557,646 3,496,370 Blended 7 4.55 8 Term debt / Senior notes Bridge Facility 6 475,000 — Variable 3.09 Term debt Financing obligations 62,200 77,066 Imputed 5.85 8 Financing lease obligations Total principal due for long-term debt and financing obligations 6,294,721 5,796,936 4.53 8 Unamortized premiums and discounts, net 3,758 (15,913 ) Deferred financing costs, net (38,036 ) (19,178 ) Less: current portion of long-term debt and financing lease obligations (635,929 ) (464,332 ) Long-term debt and financing obligations, less current portion $ 5,624,514 $ 5,297,513 ——— (1) As of September 30, 2019 . (2) Represents the debt issued by TerraForm Power Operating, LLC (“Terra Operating LLC”) and guaranteed by Terra LLC and certain subsidiaries of TerraForm Operating LLC other than non-recourse subsidiaries as defined in the relevant debt agreements (except for certain unencumbered non-recourse subsidiaries). (3) Subsequent to quarter end, on October 16, 2019, Terra Operating LLC issued $700.0 million of 4.75% senior notes due on January 15, 2030 at an offering price of 100% of the principal amount. The proceeds from the notes were used to redeem, in full, the Company’s existing Senior Notes due 2025 and Term Loan (as defined below). See Note 21. Subsequent Events for additional details. (4) Represents the amounts outstanding under the Terra Operating LLC senior secured revolving credit facility (the “Revolver”). Subsequent to quarter end, on October 8, 2019, the Company entered into an amendment whereby it, among other things, increased the aggregate lending commitment by $200.0 million . See Note 21. Subsequent Events for additional details. As of October 31, 2019, the Company repaid most the outstanding balance under the Revolver. (5) Represents the amounts outstanding under Terra Operating LLC’s senior secured term loan facility (the “Term Loan”). Subsequent to quarter end, on October 16, 2019 , the Company redeemed the entire outstanding balance. See Note 21. Subsequent Events for additional details. (6) Represents senior secured term debt issued to fund a portion of the consideration paid for the WGL Acquisition. See below for additional details. (7) Includes fixed and variable rate debt. As of September 30, 2019 , 36 % of this balance had a fixed interest rate and the remaining 64 % of this balance had a variable interest rate. The Company entered into interest rate swap agreements to fix the interest rates of the majority of the variable rate permanent financing non-recourse debt (see Note 12. Derivatives for additional details). (8) Represents the weighted-average interest rate as of September 30, 2019 . Corporate Financing See Note 21. Subsequent Events , for discussion of the corporate financing transactions that were executed subsequent to quarter end. Non-recourse Project Financing Indirect subsidiaries of the Company have incurred long-term non-recourse debt obligations with respect to the renewable energy facilities that those subsidiaries own directly or indirectly. The indebtedness of these subsidiaries is typically secured by the projects’ assets (mainly the renewable energy facilities) or equity interests in subsidiaries that directly or indirectly hold renewable energy facilities with no recourse to TerraForm Power, Terra LLC or Terra Operating LLC other than limited or capped contingent support obligations, which in aggregate are not considered material to the Company’s business and financial condition. In connection with these financings and in the ordinary course of its business, the Company 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 each of TerraForm Power, Terra LLC, Terra Operating LLC and the guarantors under the Senior Notes due 2023, the Senior Notes due 2025, the Senior Notes due 2028, the Revolver, the Sponsor Line and the Term Loan. United States Project Financing On August 30, 2019, one of the Company’s subsidiaries entered into a new non-recourse debt financing agreement, whereby it issued $131.0 million of 3.2% senior notes secured by approximately 111 MW of utility-scale wind power plants located in the United States that are owned by certain of the Company’s subsidiaries. The proceeds of this financing were used to repay a portion of the balance outstanding under the Revolver. The non-recourse senior notes mature on July 2, 2032 and amortize on an approximately thirteen-year sculpted amortization schedule. Bridge Facility On September 25, 2019, one of the Company’s subsidiaries entered into a $475.0 million new non-recourse senior secured term loan (“Bridge Facility”) secured by the approximately 320 MW portfolio of distributed generation power plants located in the United States that were acquired from subsidiaries of AltaGas. The proceeds of this financing were used to fund a portion of the WGL Acquisition. See Note 4. Acquisitions for additional details. The Bridge Facility matures on September 23, 2020. The Company has a one-year extension option and intends, through its subsidiaries, to complete a refinancing of the balance on a long-term basis prior to maturity. The balance, net of unamortized deferred financing costs, is included within non-current liabilities in the unaudited condensed consolidated balance sheets. Non-recourse Debt Defaults As of September 30, 2019 and December 31, 2018, the Company reclassified $387.8 million and $186.3 million , respectively, of non-recourse long-term indebtedness, net of unamortized deferred financing costs and debt discounts, to current in the unaudited condensed consolidated balance sheets due to defaults still remaining as of the respective financial statements issuance dates. The defaults as of the December 31, 2018 primarily consisted of indebtedness of the Company’s solar renewable energy facility in Chile. The defaults as of September 30, 2019 also included the indebtedness of the Company’s California Ridge wind operating project in the United States. The Company continues to amortize deferred financing costs and debt discounts over the maturities of the respective financing agreements as before the violations, since the Company believes there is a reasonable likelihood that it will be, in due course, able to successfully negotiate waivers with the lenders and/or cure the existing defaults. The Company’s management 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 waivers, (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 lender’s election to enforce project security interests. Refer to Note 5. Cash and Cash Equivalents for discussion of corresponding restricted cash reclassifications to current as a result of these defaults. Maturities The aggregate contractual principal payments of long-term debt due after September 30, 2019 , excluding the amortization of debt discounts, premiums and deferred financing costs, as stated in the financing agreements, are as follows: (In thousands) Remainder of 2019 2020 2 2021 2022 2023 Thereafter Total Maturities of long-term debt 1 $ 96,852 $ 732,185 $ 269,528 $ 770,751 $ 1,220,271 $ 3,205,134 $ 6,294,721 ——— (1) Represents the contractual principal payment due dates for the Company’s long-term debt and does not reflect the reclassification of $387.8 million of long-term debt, net of unamortized deferred financing costs and debt discounts, to current due to debt defaults that existed as of the date of the issuance of the financial statements (see above for additional details). (2) Includes the $475.0 million Bridge Facility maturing on September 23, 2020. The Company has a one-year extension option and intends, through its subsidiaries, to complete a refinancing of the balance on a long-term basis prior to maturity. The balance, net of unamortized deferred financing costs, is included within non-current liabilities in the unaudited condensed consolidated balance sheets.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The income tax provision consisted of the following: Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except effective tax rate) 2019 2018 2019 2018 Loss before income tax expense $ (60,801 ) $ (13,038 ) $ (112,167 ) $ (113,559 ) Income tax expense 1,512 6,013 3,030 9,417 Effective tax rate (2.5 )% (46.1 )% (2.7 )% (8.3 )% The overall effective tax rate for the three and nine months ended September 30, 2019 and 2018 was different than the statutory rate of 21% and was primarily due to the recording of a valuation allowance on certain income tax benefits attributed to the Company, losses allocated to non-controlling interests and the effect of foreign and state taxes. As of September 30, 2019 , and December 31, 2018 , the Company had not identified any uncertain tax positions for which a liability was required under ASC 740-10. The Company expects to complete its analysis on tax positions related to the WGL Acquisition within the measurement period.

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	DERIVATIVES As part of its 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 exposures. 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 either cash flow hedges or net investment hedges. The Company enters into interest rate swap agreements in order to hedge the variability of the 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 hedge price variability inherent in energy sales arrangements. The objectives of the commodity contracts are to minimize the impact of variability in spot energy prices and stabilize estimated revenue streams. The Company does not use derivative instruments for trading or speculative purposes. As of September 30, 2019 and December 31, 2018 , the fair values of the following derivative instruments were included in the respective balance sheet captions indicated below: Fair Value of Derivative Instruments 1 Derivatives Designated as Hedging Instruments Derivatives Not Designated as Hedging Instruments (In thousands) Interest Rate Swaps Foreign Currency Contracts Commodity Contracts Interest Rate Swaps Foreign Currency Contracts Commodity Contracts Gross Derivatives Counterparty Netting 2 Net Derivatives As of September 30, 2019 Derivative assets, current $ — $ 1,217 $ 365 $ — $ 19,365 $ 8,069 $ 29,016 $ (108 ) $ 28,908 Derivative assets — 9,831 41,679 — 4,346 42,019 97,875 (779 ) 97,096 Total assets $ — $ 11,048 $ 42,044 $ — $ 23,711 $ 50,088 $ 126,891 $ (887 ) $ 126,004 Derivative liabilities, current portion $ 5,717 $ 108 $ — $ 33,012 $ — $ — $ 38,837 $ (108 ) $ 38,729 Derivative liabilities 35,585 4 — 105,570 775 — 141,934 (779 ) 141,155 Total liabilities $ 41,302 $ 112 $ — $ 138,582 $ 775 $ — $ 180,771 $ (887 ) $ 179,884 As of December 31, 2018 Derivative assets, current $ 1,478 $ 605 $ 18 $ — $ 3,344 $ 9,783 $ 15,228 $ (857 ) $ 14,371 Derivative assets 5,818 2,060 42,666 — 647 40,137 91,328 (344 ) 90,984 Total assets $ 7,296 $ 2,665 $ 42,684 $ — $ 3,991 $ 49,920 $ 106,556 $ (1,201 ) $ 105,355 Derivative liabilities, current portion $ 465 $ — $ — $ 34,267 $ 1,684 $ — $ 36,416 $ (857 ) $ 35,559 Derivative liabilities 3,334 1,437 — 88,034 1,387 — 94,192 (344 ) 93,848 Total liabilities $ 3,799 $ 1,437 $ — $ 122,301 $ 3,071 $ — $ 130,608 $ (1,201 ) $ 129,407 ———— (1) Fair value amounts are shown before the effect of counterparty netting adjustments. (2) Represents the netting of derivative exposures covered by qualifying master netting arrangements. As of September 30, 2019 and December 31, 2018 , 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 September 30, 2019 and December 31, 2018 related to the Company’s derivative transactions. The Company is subject to credit risk related to its derivatives to the extent the hedge counterparties may be unable to meet the terms of the contractual arrangements. The maximum exposure to loss due to credit risk if counterparties fail completely to perform according to the terms of the contracts would generally equal the fair value of derivative assets presented in the above table. The Company seeks to mitigate credit risk by transacting with a group of creditworthy financial institutions and through the use of master netting arrangements. The Company elected to present all derivative assets and liabilities on a net basis on the balance sheet as a right to set-off exists. The Company enters into International Swaps and Derivatives Association, Inc. (“ISDA”) Master Agreements with its counterparties. An ISDA Master Agreement is an agreement that can govern multiple derivative transactions between two counterparties that typically provides for the net settlement of all, or a specified group, of these derivative transactions through a single payment, and in a single currency, as applicable. A right to set-off typically exists when the Company has a legally enforceable ISDA Master Agreement. No amounts were netted for commodity contracts as of September 30, 2019 or December 31, 2018 , as each of the commodity contracts were in a gain position. The following table presents the notional amounts of derivative instruments as of September 30, 2019 and December 31, 2018 : Notional Amount as of (In thousands) September 30, 2019 December 31, 2018 Derivatives designated as hedging instruments: Cash flow hedges: Interest rate swaps (USD) 867,184 357,797 Interest rate swaps (CAD) 139,075 147,522 Commodity contracts (MWhs) 5,528 6,030 Net investment hedges: Foreign currency contracts (CAD) 94,100 81,600 Foreign currency contracts (EUR) 200,000 320,000 Derivatives not designated as hedging instruments: Interest rate swaps (USD) 11,616 12,326 Interest rate swaps (EUR) 1 991,942 1,044,253 Foreign currency option contracts (EUR) 2 625,200 — Foreign currency forward contracts (EUR) 2 165,000 640,200 Foreign currency contracts (CAD) 7,800 — Commodity contracts (MWhs) 7,895 8,707 ———— (1) Represents the notional amount of the interest rate swaps at Saeta to economically hedge the interest payments on non-recourse debt. The Company did not designate these derivatives as hedging instruments under ASC 815 as of September 30, 2019 and December 31, 2018 . (2) Represents the notional amount of foreign currency contracts used to economically hedge a portion of the Company’s foreign exchange risk associated with Euro-denominated intercompany loans. The Company did not designate these derivatives as hedging instruments under ASC 815 as of September 30, 2019 and December 31, 2018 . Gains and losses on derivatives not designated as hedging instruments for the three and nine months ended September 30, 2019 and 2018 consisted of the following: Location of Loss (Gain) in the Statements of Operations Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2019 2018 2019 2018 Interest rate swaps Interest expense, net $ 20,911 $ 4,737 $ 50,189 $ (3,252 ) Foreign currency contracts Loss (gain) on foreign currency exchange, net (19,667 ) (4,348 ) (39,596 ) (16,914 ) Commodity contracts Operating revenues, net 307 (3,880 ) (13,311 ) (21,374 ) Gains and losses recognized related to interest rate swaps, foreign currency contracts and commodity derivative contracts designated as hedging instruments for the three and nine months ended September 30, 2019 and 2018 consisted of the following: Three Months Ended September 30, Derivatives in Cash Flow and Net Investment Hedging Relationships (Loss) Gain 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 Location of Amount Reclassified from AOCI into Income Loss (Gain) Included in the Assessment of Effectiveness Reclassified from AOCI into Income 2 Gain Excluded from the Assessment of Effectiveness that is Amortized through Earnings (In thousands) 2019 2018 2019 2018 2019 2018 2019 2018 Interest rate swaps $ (14,722 ) $ 4,107 $ — $ — Interest expense, net $ 128 $ 263 $ — $ — Foreign currency contracts 11,915 3,549 — — Loss on foreign currency exchange, net — — — — Commodity contracts (6,760 ) 4,645 — — Operating revenues, net 4,794 (5,019 ) — (251 ) Total $ (9,567 ) $ 12,301 $ — $ — $ 4,922 $ (4,756 ) $ — $ (251 ) ———— (1) Net of $2,506 tax benefit attributed to interest rate swaps recorded for the three months ended September 30, 2019 . No tax expense or benefit was recorded for the three months ended September 30, 2018 . (2) No tax expense or benefit was recorded for the three months ended September 30, 2019 and 2018 . Nine Months Ended September 30, Derivatives in Cash Flow and Net Investment Hedging Relationships (Loss) Gain 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 Location of Amount Reclassified from AOCI into Income Loss (Gain) Included in the Assessment of Effectiveness Reclassified from AOCI into Income 2 (Gain) Excluded from the Assessment of Effectiveness that is Amortized through Earnings (In thousands) 2019 2018 2019 2018 2019 2018 2019 2018 Interest rate swaps $ (41,336 ) $ 14,627 $ — $ — Interest expense, net $ (867 ) $ 1,236 $ — $ — Foreign currency contracts 20,191 3,549 — — (Gain) on foreign currency exchange, net — — — — Commodity contracts (2,605 ) (2,834 ) — 735 Operating revenues, net 4,116 (7,061 ) — (930 ) Total $ (23,750 ) $ 15,342 $ — $ 735 $ 3,249 $ (5,825 ) $ — $ (930 ) ———— (1) Net of $2,506 tax benefit attributed to interest rate swaps recorded for the nine months ended September 30, 2019 . No tax expense or benefit was recorded for the nine months ended September 30, 2018 . (2) No tax expense or benefit attributed to interest rate swaps was recorded for the nine months ended September 30, 2019 and 2018 . Derivatives Designated as Hedging Instruments Interest Rate Swaps The Company has interest rate swap agreements to hedge certain variable rate non-recourse debt and its Term Loan. These interest rate swaps qualify for hedge accounting and were designated as cash flow hedges. Under the interest rate swap agreements, the Company pays a fixed rate and the counterparties to the agreements pay a variable interest rate. The change in the fair value of the components included in the effectiveness assessment of these derivatives is initially reported in AOCI and subsequently reclassified to earnings in the periods when the hedged transactions affect earnings (the payment of interest). The amounts deferred in AOCI and reclassified into earnings during the three and nine months ended September 30, 2019 and 2018 related to these interest rate swaps are provided in the tables above. The loss expected to be reclassified into earnings over the next twelve months is approximately $5.2 million . The maximum term of outstanding interest rate swaps designated as hedging instruments is 20 years. Foreign Currency Forward Contracts The Company uses foreign currency forward contracts to hedge portions of its net investment positions in certain subsidiaries with Euro (“€”) and Canadian dollar (“C$”) functional currencies and to manage its foreign exchange risk. For instruments that are designated and qualify as hedges of net investment in foreign operations, the effective portion of the net gains or losses attributable to changes in exchange rates are recorded in foreign currency translation adjustments within AOCI. The recognition in earnings of amounts previously recorded in AOCI is limited to circumstances such as complete or substantial liquidation of the net investment in the hedged foreign operation. Cash flows from derivative instruments designated as net investment hedges are classified as investing activities in the unaudited consolidated condensed statements of cash flows. As of September 30, 2019 , the total notional amount of foreign currency forward contracts designated as net investment hedges was € 200 million and approximately C$ 94.1 million . The maturity dates of these derivative instruments designated as net investment hedges range from 3 to 18 months. As of December 31, 2018 , the total notional amount of foreign currency forward contracts designated as net investment hedges was € 320 million and C$ 81.6 million . The maturity dates of these derivative instruments designated as net investment hedges range from 3 months to 2 years. Commodity Contracts The Company has two long-dated physically delivered commodity contracts that hedge variability in cash flows associated with the sales of power from certain wind renewable energy facilities located in Texas. One of these commodity contract qualifies for hedge accounting and is designated as a cash flow hedge. The change in the fair value of the components included in the effectiveness assessment of this derivative is initially reported in AOCI and subsequently reclassified to earnings in the periods when the hedged transactions affect earnings (the sale of electricity). The amounts deferred in AOCI and reclassified into earnings during the three and nine months ended September 30, 2019 and 2018 related to this commodity contract are provided in the tables above. The gain expected to be reclassified into earnings over the next twelve months is approximately $2.4 million . The maximum term of the outstanding commodity contract designated as a hedging instrument is 8 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 derivatives are not accounted for under hedge accounting. Foreign Currency Contracts The Company has foreign currency forward and option contracts that economically hedge its exposure to foreign currency fluctuations. As these hedges are not accounted for under hedge accounting, the changes in fair value are recorded in loss (gain) on foreign currency exchange, net in the unaudited condensed consolidated statements of operations. Commodity Contracts

Fair Value of Financial Instrum

Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS The fair values 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 the extrapolation from or interpolation between actively traded contracts, as well as the 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 the 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 determine the fair value of its derivative assets and liabilities. The primary inputs in the valuation models for commodity contracts are market observable forward commodity curves, risk-free discount rates, volatilities and, to a lesser degree, credit spreads. 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: As of September 30, 2019 As of December 31, 2018 (In thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Interest rate swaps $ — $ — $ — $ — $ — $ 7,296 $ — $ 7,296 Commodity contracts — 7,553 84,579 92,132 — 12,816 79,788 92,604 Foreign currency contracts — 33,872 — 33,872 — 5,455 — 5,455 Total derivative assets $ — $ 41,425 $ 84,579 $ 126,004 $ — $ 25,567 $ 79,788 $ 105,355 Liabilities Interest rate swaps $ — $ 179,884 $ — $ 179,884 $ — $ 126,100 $ — $ 126,100 Foreign currency contracts — — — — — 3,307 — 3,307 Total derivative liabilities $ — $ 179,884 $ — $ 179,884 $ — $ 129,407 $ — $ 129,407 The Company’s interest rate swaps, foreign currency contracts and financial commodity contracts are considered Level 2, since all significant inputs are corroborated by market observable data. The Company’s long-term physically settled commodity contracts (see Note 12. Derivatives ) 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 nine months ended September 30, 2019 and 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 nine months ended September 30, 2019 and 2018 : Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2019 2018 2019 2018 Beginning balance $ 86,079 $ 81,859 $ 79,652 $ 80,268 Realized and unrealized gains (losses): Included in other comprehensive (loss) income (6,760 ) 418 (2,605 ) (10,090 ) Included in operating revenues, net (2,295 ) 1,324 3,793 16,873 Settlements 7,555 583 3,739 (2,867 ) Ending balance $ 84,579 $ 84,184 $ 84,579 $ 84,184 The significant unobservable inputs used in the valuation of the Company’s commodity contracts classified as Level 3 in the fair value hierarchy as of September 30, 2019 are as follows: (In thousands, except range) Fair Value as of Transaction Type Assets Liabilities Valuation Technique Unobservable Inputs as of September 30, 2019 Commodity contracts - power $ 84,579 $ — Option model Volatilities 14.5% Range Discounted cash flow Forward price (per MWh) $7.15 - $177.20 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. An increase in the estimates of the price volatility will produce a mark-to-market gain, while a decrease in volatility will result in a mark-to-market loss. Fair Value of Debt The carrying amount and estimated fair value of the Company’s long-term debt as of September 30, 2019 and December 31, 2018 was follows: As of September 30, 2019 As of December 31, 2018 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt $ 6,260,443 $ 6,521,099 $ 5,761,845 $ 5,789,702 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 period. The fair values of the Senior Notes due 2023, Senior Notes due 2025 and Senior Notes due 2028 were 102.4% , 104.8% and 106.1% of the face value as of September 30, 2019 , respectively. The fair values of the Senior Notes due 2023, Senior Notes due 2025 and Senior Notes due 2028 were 93.5% , 89.8% and 102.5% of the face value as of December 31, 2018 , respectively. Nonrecurring Fair Value Measurements Assets and liabilities that are measured at fair value on a nonrecurring basis relate primarily to renewable energy facilities, goodwill and intangibles, which are remeasured when the derived fair value is below the carrying value. For these assets, the Company does not periodically adjust carrying value to fair value except in the event of impairment. When the impairment has occurred, the Company measures the required charges and adjusts the carrying value. For discussion about the impairment testing of assets and liabilities not measured at fair value on a recurring basis, see Note 6. Renewable Energy Facilities .

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY TerraForm Power, Inc. has 100,000,000 authorized shares of preferred stock of par value $0.01 per share, and 1,200,000,000 authorized shares of Common Stock of par value $0.01 per share. There are no other authorized classes of shares and the Company does not have any issued shares of preferred stock. The following table reflects the changes in the Company’s shares of Common Stock outstanding during the nine months ended September 30, 2019 and 2018 : Nine Months Ended September 30, (In thousands) 2019 2018 Balance as of January 1 209,142 148,086 Issuance of Common Stock to affiliates 1 — 61,056 Net shares issued under equity incentive plan 13 — Balance as of September 30 209,155 209,142 ——— (1) On June 11, 2018, the Company completed a private placement of 60,975,609 shares of the Company’s Common Stock with affiliates of Brookfield at a price of $10.66 per share for a total consideration of $650.0 million . The proceeds of the offering were used to pay a portion of the purchase price of the Tendered Shares of Saeta. On August 3, 2018, the Company issued 80,084 shares of Common Stock to an affiliate of Brookfield in connection with the net losses incurred, such as out-of-pocket losses, damages, costs, fees and expenses, in connection with the obtainment of a final resolution of a certain litigation matter. Public Offering and Private Placement of Common Stock See Note 21. Subsequent Events for a discussion of the public offering and private placement of the Company’s Common Stock that took place on October 8, 2019. Stock-based Compensation The Company has an equity incentive plan that provides for the award of incentive and nonqualified stock options, restricted stock awards 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 September 30, 2019 and December 31, 2018, an aggregate of 3,725,555 and 3,822,821 shares of Common Stock were available for issuance under this plan, respectively. Upon the vesting of RSUs, the Company issues shares that have been previously authorized to be issued. During the nine months ended September 30, 2019 , the Company awarded 156,550 time-based RSUs to certain employees of the Company. The grant-date fair value of these RSUs was $1.9 million based on the Company’s closing stock price. These RSUs are subject to a three -year vesting schedule based on the date of the Board of Directors’ approval and are recognized as compensation cost in accordance with the vesting schedule. The amount of stock-based compensation expense related to the equity awards in the Company’s stock during the three and nine months ended September 30, 2019 was $0.3 million and $0.5 million , respectively, and is reflected within cost of operations and general and administrative expenses in the unaudited condensed consolidated statement of operations. The amount of stock-based compensation expense related to the equity awards in the Company’s stock was $0.1 million and $0.2 million , respectively, during the three and nine months ended September 30, 2018 . The RSUs do not entitle the holders to voting rights and holders of the RSUs do not have any right to receive dividends or distributions. The following table presents information regarding outstanding RSUs as of September 30, 2019 and changes during the nine months ended September 30, 2019 : Number of RSUs Outstanding Weighted- Average Exercise Price Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Balance as of January 1, 2019 103,300 $ 11.15 Granted 156,550 12.17 Vested (20,878 ) 11.15 Forfeited (38,406 ) 11.65 Balance as of September 30, 2019 200,566 $ 11.85 $ 3,861.2 1.6 years The total unrecognized stock-based expense related to the Company’s RSUs at September 30, 2019 was $1.8 million and will be recognized, net of any forfeitures, over a weighted-average amortization period of 1.6 years . Cash Distributions The following table presents the cash distributions declared and paid on Common Stock during the nine months ended September 30, 2019 and 2018 : Distributions per Share Declaration Date Record Date Payment Date 2019: First Quarter $ 0.2014 March 13, 2019 March 24, 2019 March 29, 2019 Second Quarter 0.2014 May 8, 2019 June 3, 2019 June 17, 2019 Third Quarter 0.2014 August 8, 2019 September 3, 2019 September 17, 2019 2018: 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 Third Quarter 0.19 August 13, 2018 September 1, 2018 September 15, 2018 Share Repurchase Program On July 25, 2019, the Board of Directors of the Company authorized the renewal of the Company’s share repurchase program through August 4, 2020. Under the share repurchase program, the Company may repurchase up to 5% of the Company’s Common Stock outstanding as of July 25, 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 under the Exchange Act. 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 stock. The Company expects to fund any repurchases from the available liquidity. No shares have been repurchased by the Company during the nine months ended September 30, 2019.

(Loss) Earnings Per Share

(Loss) Earnings Per Share	9 Months Ended
	Sep. 30, 2019
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 (loss) income 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 represent the incremental shares issuable for unvested restricted 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 Common Stock for the three and nine months ended September 30, 2019 and 2018 was calculated as follows: Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share amounts) 2019 2018 2019 2018 Basic and diluted (loss) earnings per share: Net (loss) income attributable to Class A common stockholders $ (54,837 ) $ (33,590 ) $ (67,059 ) $ 27,869 Weighted average basic Class A shares outstanding 1 209,155 209,142 209,149 173,173 Weighted average diluted Class A shares outstanding 2 209,155 209,142 209,149 173,186 Basic and diluted (loss) earnings per share $ (0.26 ) $ (0.16 ) $ (0.32 ) $ 0.16 ——— (1) The weighted-average basic Class A shares outstanding for the nine months ended September 30, 2018 included 66 thousand contingently issuable shares. There were no contingently issuable shares for the three months ended September 30, 2018. (2) The computation of diluted earnings per share of the Company’s Common Stock for the nine months ended September 30, 2019 excluded 36 thousand of potentially dilutive unvested RSUs, respectively, because the effect would have been anti-dilutive. The computation of diluted loss per share of the Company’s Common Stock for the three months ended September 30, 2018, excludes 103 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 Common Stock for the nine months ended September 30, 2018, includes 13 thousand of RSUs considered to be dilutive and calculated using the treasury stock method.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
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 certain 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 September 30, 2019 , the Company had outstanding letters of credit drawn under the Revolver of $112.6 million and outstanding project-level letters of credit of $257.4 million drawn under certain project level financing agreements, compared to $99.5 million and $197.7 million , respectively, as of December 31, 2018 . Guarantee Agreements The Company and its subsidiaries have entered into guarantee agreements to certain of their institutional tax equity investors and financing parties in connection with their tax equity financing transactions. These agreements 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-level 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. The amounts of the above guarantees often are not explicitly stated and the overall maximum amount of the related obligations cannot be reasonably estimated. Historically, no significant payments have been made with respect to these types of guarantees. The Company believes the probability of payments being demanded under these guarantees is remote and no material amounts have been recognized for the underlying fair value of guarantee obligations. Long-Term Service Agreements On August 10, 2018, the Company executed an 11 -year framework agreement with affiliates of 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 (“LTSA”) for turbine O&M, as well as other balance of plant services across the Company’s 1.6 GW North American wind fleet. As of September 30, 2019, 15 of 16 project-level LTSAs were in place. As discussed in Note 21. Subsequent Events , on November 1, 2019, the Company executed a 10 -year framework agreement with SMA Solar Technology that, among other things, provides for the roll out, subject to receipt of third-party consents, of project level LTSAs for solar O&M, as well as other balance of plant services across the Company’s North American solar fleet . 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. 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, Inc. (“SunEdison”), TerraForm Power, 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. On February 6, 2018, the court denied the Company’s motion to dismiss after which document discovery began. In April 2019, Terra LLC filed an amended answer to the amended complaint. The Company cannot predict the impact on this litigation of any information that may become available in discovery. Document discovery and disposition are now substantially completed and new pretrial schedule has been agreed between the parties and approved by the court. The Company believes the First Wind Sellers’ allegations are without merit and will contest them 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. (“TerraForm Global”) and certain individuals, with the United States Department of Labor. The complaint alleged 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 alleged were self-interested and which he alleged SunEdison forced on the Company. He alleged 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 sought lost wages, bonuses, benefits, and other money that he alleged 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 2016. On February 21, 2017, Mr. Perez filed Gundin v. TerraForm Global, Inc. et al. against TerraForm Power, TerraForm Global and certain individuals as defendants in the United States District Court for the District of Maryland, which was subsequently transferred to the U.S. District Court for the Southern District of New York (“SDNY”). The complaint asserted 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 8, 2018, Mr. Perez voluntarily dismissed the federal action without prejudice. On December 27, 2018, the proceeding before the Department of Labor was dismissed, which Mr. Perez appealed on January 25, 2019. On August 27, 2019, pursuant to Mr. Perez’s offer to settle the dispute, a definitive settlement agreement was executed between the Company and Mr. Perez. The settlement with Mr. Perez was paid entirely from insurance proceeds. 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 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 2016. On February 21, 2017, Mr. Domenech filed Domenech Zornoza v. TerraForm Global, Inc. et. al against TerraForm Power, TerraForm Global and certain individuals as defendants in the United States District Court for the District of Maryland. The complaint asserted 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 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. On August 16, 2018, Mr. Domenech filed a second complaint with the United States District Court for the District of Maryland, with substantially the same allegations. On October 17, 2018, the Company filed notice with the Judicial Panel on Multidistrict Litigation to transfer this action to the SDNY. The Plaintiff opposed the transfer. However, the transfer was approved by the Judicial Panel on Multidistrict Litigation. On March 15, 2019, the Company, TerraForm Global, and several individual defendants filed a joint motion to dismiss Mr. Domenech’s complaint. Mr. Domenech filed a response on April 15, 2019, and the Company, TerraForm Global, and the individual defendants filed a reply on April 25, 2019. The motion to dismiss is pending as of the date of this Quarterly Report. Derivative Class Action On September 19, 2019, lead plaintiff Martin Rosson filed a derivative and class action lawsuit in the Delaware Court of Chancery on behalf of the Company, himself, and other minority stockholders of the Company against Brookfield and certain of its affiliates (including the Company as a nominal defendant). The complaint alleges that the defendant controlling stockholders breached their fiduciary duty to minority stockholders because the Company undertook a private placement of the Company’s stock on terms that the complaint alleges are unfair, instead of pursuing a public offering. The proceeds of the private placement were used to fund the acquisition by the Company of Saeta and had been approved by the Conflicts Committee of the Company’s Board of Directors. The complaint seeks the rescission and invalidation of the private placement and payment to the Company of rescissory damages, among other relief. In a related development, on October 15, 2019, the Company received a demand letter (the “220 Demand”) for the production of books and records pursuant to 8 Del. C. § 220 to allow counsel to a purported shareholder of the Company to investigate potential breaches of fiduciary duty by Brookfield and the Company’s Board of Directors in connection with the funding of the acquisition of Saeta. The Company believes that these claims are without merit. However, the Company cannot predict with certainty the ultimate resolution of any proceedings brought in connection with these claims. Chile Project Arbitration On September 5, 2016, Compañía Minera del Pacífico (“CMP”) submitted demands for arbitration against the subsidiary of the Company that owns its solar 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 alleged, 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 alleged that it is entitled to damages based on alleged breaches of a call option agreement entered into by the parties. In June 2019, the CAM issued two rulings in which it unanimously rejected the claims made by CMP. CMP indicated that they would not seek to appeal the ruling and the window in which they are permitted to appeal has now closed. Other Matters Two of the Company’s project level subsidiaries are parties to litigation that is seeking to recover alleged underpayments of tax grants under Section 1603 of the American Recovery and Reinvestment Tax Act from the U.S. Department of Treasury (“U.S. Treasury”). These project level subsidiaries filed complaints at the Court of Federal Claims on March 28, 2014. The U.S. Treasury counterclaimed and both claims went to trial in July 2018. In January 2019, the Court of Federal Claims entered judgments against each of the project level subsidiaries for approximately $10.0 million in the aggregate. These judgments are being appealed. The project level subsidiaries expect that losses, if any, arising from these claims would be covered pursuant to an indemnity and, accordingly, the Company recognized a corresponding indemnification asset within prepaid expenses and other current assets in the consolidated balance sheets as of September 30, 2019 and December 31, 2018. Issuance of Shares upon Final Resolution of Certain Litigation Matters Pursuant to the definitive merger and sponsorship agreement (the “Merger Agreement”) entered into with Orion Holdings on March 6, 2017, the Company has agreed to issue additional shares of 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 (including 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 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 on Schedule 14A filed 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. The settlement with Mr. Perez was paid entirely from insurance proceeds and no shares have been issued to Brookfield in connection with the settlement. 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 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. Commitment to purchase renewable energy facilities In connection with the acquisition of three distributed generation facilities in the U.S. with a combined nameplate capacity of 10.6 MW, the Company is also committed to purchase an additional facility with a nameplate capacity of 4.5 MW for a purchase price of $6.0 million . This acquisition is expected to be completed in December 2019. See Note 4. Acquisitions for additional details.

Related Parties

Related Parties	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Related Parties	RELATED PARTIES As discussed in Note 1. Nature of Operations and Organization , the Company is a controlled affiliate of Brookfield which held 65% of the voting securities of TerraForm Power’s Common Stock as of September 30, 2019 and December 31, 2018. Subsequent to quarter end, on October 8, 2019, the Company completed a public offering of its Common Stock. Concurrent with the public offering, the Company completed a private placement with affiliates of Brookfield of 2,981,514 shares of Common Stock pursuant to a stock purchase agreement dated October 8, 2019. The combined ownership of affiliates of Brookfield became approximately 61% as of the date of this Quarterly Report. See Note 21. Subsequent Events for additional details. Brookfield Sponsorship Transaction The Company entered into a suite of agreements with Brookfield and/or certain of its affiliates providing for sponsorship arrangements, as are more fully described below. Brookfield Master Services Agreement 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 the Brookfield MSA, the Company pays a base management fee on a quarterly basis that is paid in arrears and calculated as follows: • for each of the first four quarters following the closing date of the Merger contemplated by the Merger Agreement (the “Merger”), a fixed component of $2.5 million per quarter (subject to proration for the quarter including the closing date of the Merger) plus 0.3125% of the market capitalization value increase for such quarter; • for each of the next four quarters, a fixed component of $3.0 million per quarter adjusted annually for inflation plus 0.3125% of the market capitalization value increase for such quarter; and • thereafter, a fixed component of $3.75 million per quarter adjusted annually for inflation plus 0.3125% of the market capitalization value increase for such quarter. For purposes of calculating the quarterly payment of the base management fee, the term market capitalization value increase means, for any quarter, the increase in value of the Company’s market capitalization for such quarter, calculated by multiplying the number of outstanding shares of Common Stock as of the last trading day of such quarter by the difference between (x) the volume-weighted average trading price of a share of Common Stock for the trading days in such quarter and (y) $9.52 . If the difference between (x) and (y) in the market capitalization value increase calculation for a quarter is a negative number, then the market capitalization value increase is deemed to be zero. Pursuant to the Brookfield MSA, the Company recorded charges of $7.5 million and $18.3 million within general and administrative expenses - affiliate in the consolidated statements of operations for the three and nine months ended September 30, 2019 , respectively, compared to $3.6 million and $10.5 million for the same periods in 2018 , respectively. The balance payable under the Brookfield MSA was $7.5 million and $4.2 million in the consolidated balance sheets as of September 30, 2019 and December 31, 2018 , respectively. Relationship Agreement 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 rights of the Company under the Relationship Agreement are subject to certain exceptions and consent rights set out therein. The Company did not acquire any renewable energy facilities from Brookfield during the nine months ended September 30, 2019 and 2018. Terra LLC Agreement BRE Delaware, Inc. (the “Brookfield IDR Holder”), an indirect, wholly-owned subsidiary of Brookfield, holds all of the outstanding incentive distribution rights (“IDRs”) of Terra LLC. The Company, Brookfield IDR Holder and TerraForm Power Holdings, Inc. are party to the limited liability company agreement of Terra LLC (as amended from time to time, the “Terra LLC Agreement”). Under the Terra LLC Agreement, IDRs are payable when distributions on Common Stock reach a certain threshold. The IDR threshold for a first distribution is $0.93 per share of Common Stock and for a second distribution is $1.05 per share of Common Stock. There were no IDR payments made by the Company pursuant to the Terra LLC Agreement during the nine months ended September 30, 2019 and 2018 . Registration Rights Agreement The Company entered into a registration rights agreement (the “Registration Rights Agreement”) on October 16, 2017 with Orion Holdings. On June 11, 2018, Orion Holdings, Brookfield BRP Holdings (Canada) Inc. and the Company entered into a Joinder Agreement pursuant to which Brookfield BRP Holdings (Canada) Inc. became a party to the Registration Rights Agreement. On June 29, 2018, a second Joinder Agreement was entered into among Orion Holdings, Brookfield BRP Holdings (Canada) Inc., BBHC Orion Holdco L.P. and the Company pursuant to which BBHC Orion Holdco L.P. became a party to the Registration Rights Agreement. The Registration Rights Agreement governs the rights and obligations of the parties thereto with respect to the registration for resale of all or a part of the Class A shares held by Orion Holdings, BBHC Orion Holdco L.P and such other affiliates of Brookfield from time to time to the Registrations Rights Agreement. Sponsor Line Agreement On October 16, 2017, the Company entered into a credit agreement (the “Sponsor Line”) with Brookfield and one of its affiliates. The Sponsor Line establishes a $500.0 million secured revolving credit facility 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 Sponsor Line (subject to acceleration for certain specified events). The Company may only use the revolving Sponsor Line to fund all or a portion of certain funded acquisitions or growth capital expenditures. The Sponsor Line will terminate, and all obligations thereunder will become payable, no later than October 16, 2022. Borrowings under the Sponsor Line bear interest at a rate per annum equal to a LIBOR rate determined by reference to the costs of funds for U.S. dollar deposits for the interest period relevant to such borrowing adjusted for certain additional costs, in each case plus 3.00% per annum. In addition to paying interest on outstanding principal under the Sponsor Line, the Company is required to pay a standby fee of 0.50% per annum in respect of the unutilized commitments thereunder, payable quarterly in arrears. The Company is permitted to voluntarily reduce the unutilized portion of the commitment amount and repay outstanding loans under the Sponsor Line at any time without premium or penalty, other than customary “breakage” costs. TerraForm Power’s obligations under the Sponsor Line are secured by first-priority security interests in substantially all assets of TerraForm Power, including 100% of the capital stock of Terra LLC, in each case subject to certain exclusions set forth in the credit documentation governing the Sponsor Line. Under certain circumstances, the Company may be required to prepay amounts outstanding under the Sponsor Line. Total interest expense recognized on the Sponsor Line for the three and nine months ended September 30, 2019 amounted to $1.0 million and $3.1 million , respectively, compared to $1.9 million and $4.1 million for the same periods in 2018 . Governance Agreement In connection with the consummation of the Merger, the Company entered into a governance agreement (the “Governance Agreement”) with Orion Holdings and any controlled affiliate of Brookfield (other than the Company and its controlled affiliates) that by the terms of the Governance Agreement from time to time becomes a party thereto. The Governance Agreement establishes 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 the relationship between such affiliates of Brookfield and the Company and its controlled affiliates. On June 11, 2018, Orion Holdings, Brookfield BRP Holdings (Canada) Inc. and the Company entered into a Joinder Agreement pursuant to which Brookfield BRP Holdings (Canada) Inc. became a party to the Governance Agreement. On June 29, 2018, a second Joinder Agreement was entered into among Orion Holdings, Brookfield BRP Holdings (Canada) Inc., BBHC Orion Holdco L.P. and the Company pursuant to which BBHC Orion Holdco L.P. became a party to the Governance Agreement. New York Office Lease & Co-tenancy Agreement 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. The Company recorded $0.3 million and $0.7 million of charges within general and administrative expenses - affiliate in the unaudited condensed consolidated statements of operations for the three and nine months ended September 30, 2019 , respectively compared to $0.2 million for the three and nine months ended September 30, 2018 . Due from Affiliates The $0.3 million due from affiliates amount reported in the unaudited condensed consolidated balance sheets as of September 30, 2019 primarily represented a receivable for office space rent and related expenses and other charges paid by the Company on behalf of an affiliate of Brookfield under the New York Office Lease and Co-Tenancy Agreement referred to above. During the nine months ended September 30, 2019 , the Company collected the $0.2 million receivable that was outstanding at December 31, 2018 from TerraForm Global, a controlled affiliate of Brookfield, for 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. Due to Affiliates The $8.9 million due to affiliates amount reported in the unaudited condensed consolidated balance sheets as of September 30, 2019 represented payables to affiliates of Brookfield of $7.5 million for the Brookfield MSA base management fee for the third quarter of 2019 and $1.4 million payables related to rent, office charges and other services. The $7.0 million due to affiliates amount reported in the consolidated balance sheets as of December 31, 2018 represented payables to affiliates of Brookfield of $4.2 million for the Brookfield MSA quarterly base management fee for the fourth quarter of 2018 and $2.8 million for leasehold improvements, rent, office charges and other services during 2018. During the three and nine months ended September 30, 2019, the Company paid to affiliates of Brookfield $5.9 million and $15.0 million , respectively, for the Brookfield MSA base management fee and $2.1 million and $5.3 million , respectively, representing standby fee interest payable to a Brookfield affiliate under the Sponsor Line and for leasehold improvements, rent, office charges and other services with affiliates of Brookfield. During the three and nine months ended September 30, 2018, the Company paid to affiliates of Brookfield $3.6 million and $10.3 million , respectively for the Brookfield MSA base management fee and $2.4 million and $4.2 million , respectively, representing standby fee and interest payable to a Brookfield affiliate under the Sponsor Line.

Segment Reporting

Segment Reporting	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Segment Reporting	SEGMENT REPORTING The Company has three reportable segments: Solar, Wind, and Regulated Solar and Wind. These segments, which represent the Company’s entire portfolio of renewable energy facilities, 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. Each of the Company’s reportable segments represent an aggregation of operating 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 (“CODM”) in deciding how to allocate resources. The Company’s Chief Executive Officer and Chief Financial Officer have been identified as the CODMs. The Company’s operating segments consist of: (i) Distributed Generation, North America Solar Utility, International Solar Utility, which are aggregated into the Solar reportable segment; (ii) Northeast Wind, Central Wind, Texas Wind, Hawaii Wind, Portugal Wind and Uruguay Wind operating segments, which are aggregated into the Wind reportable segment; and (iii) the Spanish Regulated Solar and Spanish Regulated Wind operating segments that are aggregated within the Regulated Solar and Wind reportable segment. Portugal Wind, Uruguay Wind, and the Spanish Regulated Solar and Wind segments were added during the second quarter of 2018 upon the acquisition of Saeta and represent its entire operations (see Note 4. Acquisitions for additional details). The operating segments have been aggregated as they have similar economic characteristics and meet the aggregation criteria. The CODMs evaluate the performance of the Company’s operating segments principally based on operating income or loss. Corporate expenses include general and administrative expenses, acquisition costs, interest expense on corporate-level indebtedness, stock-based compensation and depreciation expense. All net operating revenues for the three and nine months ended September 30, 2019 and 2018 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 regarding the Company’s reportable segments for the three and nine months ended September 30, 2019 and 2018 : Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 (In thousands) Solar 1 Wind Regulated Solar and Wind Corporate Total Solar Wind Regulated Solar and Wind Corporate Total Operating revenues, net $ 101,654 $ 54,507 $ 97,647 $ — $ 253,808 $ 94,883 $ 56,963 $ 94,196 $ — $ 246,042 Depreciation, accretion and amortization expense 29,753 49,052 34,957 520 114,282 28,299 40,992 33,954 348 103,593 Other operating costs and expenses 9,912 38,120 28,085 23,044 99,161 11,109 31,302 24,971 18,401 85,783 Operating income (loss) 61,989 (32,665 ) 34,605 (23,564 ) 40,365 55,475 (15,331 ) 35,271 (18,749 ) 56,666 Interest expense, net 17,302 16,220 27,073 28,798 89,393 15,992 14,367 9,632 32,425 72,416 Other non-operating expenses (income), net 428 (132 ) 599 10,878 11,773 632 (347 ) (727 ) (2,270 ) (2,712 ) Income tax expense 3,653 401 (2,543 ) 1 1,512 749 927 2,268 2,069 6,013 Net income (loss) $ 40,606 $ (49,154 ) $ 9,476 $ (63,241 ) $ (62,313 ) $ 38,102 $ (30,278 ) $ 24,098 $ (50,973 ) $ (19,051 ) Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 (In thousands) Solar Wind Regulated Solar and Wind 1 Corporate Total Solar 3 Wind Regulated Solar and Wind 1 Corporate Total Operating revenues, net $ 241,593 $ 223,982 $ 268,931 $ — $ 734,506 $ 237,927 $ 200,068 $ 115,482 $ — $ 553,477 Depreciation, accretion and amortization expense 84,829 132,694 102,955 1,127 321,605 83,041 113,926 41,148 1,062 239,177 Impairment of renewable energy facilities — — — — — 15,240 — — — 15,240 Other operating costs and expenses 41,274 113,585 66,791 66,854 288,504 39,792 89,834 30,012 77,506 237,144 Operating income (loss) 115,490 (22,297 ) 99,185 (67,981 ) 124,397 99,854 (3,692 ) 44,322 (78,568 ) 61,916 Interest expense, net 46,693 45,173 65,539 89,316 246,721 46,248 36,382 4,879 89,353 176,862 Other non-operating (income) expenses, net (6,391 ) (550 ) 449 (3,665 ) (10,157 ) (1,926 ) 538 (617 ) 618 (1,387 ) Income tax expense 1,532 830 553 115 3,030 749 1,291 4,442 2,935 9,417 Net income (loss) $ 73,656 $ (67,750 ) $ 32,644 $ (153,747 ) $ (115,197 ) $ 54,783 $ (41,903 ) $ 35,618 $ (171,474 ) $ (122,976 ) Balance Sheet Total assets 2,3 3,587,474 3,762,649 2,496,186 82,882 $ 9,929,191 2,762,977 3,733,049 2,748,126 86,202 $9,330,354 ——— (1) The Company’s Regulated Solar and Wind segment and wind operations in Portugal and Uruguay were added in the second quarter of 2018 upon acquiring a controlling interest in Saeta. See Note 4. Acquisitions for additional details. (2) Total assets within the Solar reporting segment as of September 30, 2019 include $693.9 million of assets from the WGL Acquisition that was completed on September 26, 2019. See Note 4. Acquisitions for additional details. (3) Represents total assets as of September 30, 2019 and December 31, 2018 , respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Accumulated Other Comprehensive Income	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, 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) income: Net unrealized (loss) gain arising during the period (net of zero tax impact) (8,229 ) 12,528 4,299 Reclassification of net realized gain into earnings (net of zero tax impact) — (6,755 ) (6,755 ) Other comprehensive (loss) income (8,229 ) 5,773 (2,456 ) Accumulated other comprehensive (loss) income (21,641 ) 63,039 41,398 Less: Other comprehensive loss attributable to non-controlling interests — (3,038 ) (3,038 ) Balance as of September 30, 2018 $ (21,641 ) $ 66,077 $ 44,436 (In thousands) Foreign Currency Translation Adjustments Hedging Activities 1 Accumulated Other Comprehensive Income Balance as of December 31, 2018 $ (8,405 ) $ 48,643 $ 40,238 Other comprehensive (loss) income: Net unrealized gain (loss) arising during the period (net of zero and $2,506 tax benefit, respectively) 15,806 (43,941 ) (28,135 ) Reclassification of net realized gain into earnings (net of zero tax impact) — (2,439 ) (2,439 ) Other comprehensive income (loss) 15,806 (46,380 ) (30,574 ) Accumulated other comprehensive income 7,401 2,263 9,664 Less: Other comprehensive income attributable to non-controlling interests — 920 920 Balance as of September 30, 2019 $ 7,401 $ 1,343 $ 8,744 ——— (1) See Note 12. Derivatives for additional breakout of hedging gains and losses for interest rate swaps and commodity contracts in a cash flow hedge relationship and the foreign currency contracts designated as hedges of net investments in foreign operations. (2) Represents the impact of the adoption of ASU No. 2017-12 as of January 1, 2018.

Non-controlling Interests

Non-controlling Interests	9 Months Ended
	Sep. 30, 2019
Noncontrolling Interest [Abstract]
Non-controlling Interests	NON-CONTROLLING INTERESTS Non-controlling interests represent the portion of net assets in consolidated entities that are not owned by the Company and are reported as a component of equity in the unaudited condensed consolidated balance sheets. Non-controlling interests in subsidiaries that are redeemable either at the option of the holder or at fixed and determinable prices at certain dates in the future are classified as redeemable non-controlling interests in subsidiaries between liabilities and stockholders’ equity in the unaudited condensed consolidated balance sheets. Redeemable non-controlling interests that are currently redeemable or redeemable after the passage of time are adjusted to their redemption value as changes occur. However, the non-controlling interests balance cannot be less than the estimated redemption value. The following table presents the activity of the redeemable non-controlling interests balance for the nine months ended September 30, 2019 and 2018: Nine Months Ended September 30, (In thousands) 2019 2018 Balance as of January 1 $ 33,495 $ 34,660 Cumulative-effect adjustment 1 — (4,485 ) Net loss (14,241 ) 15,101 Distributions (852 ) (1,993 ) Repurchases of redeemable non-controlling interests, net 2 (4,753 ) 617 Non-cash redemption of redeemable non-controlling interests 7,345 — Balance as of September 30 $ 20,994 $ 43,900 ——— (1) Represents the effect from the adoption of ASU No. 2014-09 and ASU No. 2016-08 as of January 1, 2018. (2) See below for additional details. Repurchases of non-controlling interests During the nine months ended September 30, 2019, the Company purchased the tax equity investors’ interests in certain distributed generation projects in the United States for a combined consideration of $3.9 million , which resulted in increasing the Company’s ownership interest in the related projects to 100% . The difference between the consideration paid and the carrying amounts of the non-controlling interests was recorded as an adjustment to additional paid-in capital within Purchase of (redeemable) non-controlling interests in renewable energy facilities in the unaudited condensed consolidated statement of stockholders’ equity. 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 nine months ended September 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.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS Public Offering and Private Placement of Common Stock On October 8, 2019, the Company completed an underwritten registered public offering of 14,907,573 shares of Common Stock at a price of $16.77 per share (the “Public Offering”), for a total consideration of $250.0 million , not including transaction costs. In connection with the Public Offering, the Company entered into an underwriting agreement, dated October 3, 2019 (the “Underwriting Agreement”), among the Company, Terra LLC and RBC Capital Markets, LLC, as the underwriter (the “Underwriter”). Concurrent with the Public Offering, the Company completed a private placement of 2,981,514 shares of Common Stock at a price of $16.77 per share (the “Private Placement”), to BBHC Orion Holdco L.P., an affiliate of Brookfield (the “Purchaser”), for a total consideration of $50.0 million , not including transaction costs. In connection with the Private Placement, the Company entered into a stock purchase agreement, dated October 8, 2019, with the Purchaser. The Common Stock issued in the Private Placement were not registered with the SEC, in reliance on Section 4(a)(2) of the Securities Act and the acknowledgment of the Purchaser 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. Following the Public Offering and the Private Placement, and as of the date of the issuance of this Quarterly Report, affiliates of Brookfield held approximately 61% of the Company’s Common Stock. The proceeds of the Public Offering and Private Placement were used to pay down the amounts due under the Revolver and for general corporate purposes. Amendment to the Revolver On October 8, 2019, Terra Operating LLC entered into an amendment to the Revolver agreement (the “Upsize Amendment”) whereby (i) the aggregate size of the commitments to make revolving loans (‘‘Revolving Loans’’) under the Revolver was increased by $200.0 million to $800.00 million shared ratably among the existing lenders under the Revolver and three new incoming lenders as of October 8, 2019, (ii) the aggregate size of the letter of credit facility under the Revolver was increased by $50.0 million to $300.0 million and (iii) the accordion feature of the Revolver, which allows for further increases to the commitments to make Revolving Loans, was set at $150.0 million . Additionally, the Upsize Amendment extended the maturity date of the Revolver by one year to October 5, 2024. Private Offering of Corporate Senior Notes On October 16, 2019, Terra Operating LLC issued $700.0 million aggregate principal amount of 4.75% senior notes due on January 15, 2030 (the “Senior Notes due 2030”) in an unregistered offering pursuant to Rule 144A under the Securities Act. The Senior Notes due 2030 were sold at an offering price of 100% of the principal amount. The proceeds from the Senior Notes due 2030 were used (i) to redeem, in full, the Company’s existing Senior Notes due 2025, of which $300.0 million remained outstanding, at a redemption price that included a make-whole premium plus accrued and unpaid interest of $25.5 million , (ii) to redeem, in full, the Company’s Term Loan, of which $343.9 million remained outstanding plus accrued and unpaid interest and $8.8 million for derivative liabilities related to interest rate swaps signed with the hedge counterparties and (iii) pay for the fees and expenses related to the issuance. The remaining proceeds were used for general corporate purposes. Solar LTSA On November 1, 2019, the Company executed a 10 -year framework agreement with SMA Solar Technology that, among other things, provides for the roll out, subject to receipt of third-party consents, of project level, long-term service agreements for solar O&M, as well as other balance of plant services across the Company’s North American solar fleet . Transfer of Title of Delayed Projects In connection with the WGL Acquisition, the title to 43 Delayed Projects with a purchase value of approximately $68.8 million and a combined nameplate capacity of 18.0 MW was transferred to the Company on October 31, 2019. The remaining balance of the Delayed Projects as of the date of the issuance of this Quarterly Report was approximately $45.4 million . See Note 4. Acquisitions for additional details. Fourth Quarter Cash Distribution On November 6, 2019, the Company’s Board of Directors declared a cash distribution with respect to Common Stock of $0.2014 per share. The distribution is payable on December 16, 2019 to stockholders of record as of December 2, 2019.

Nature of Operations and Orga_2

Nature of Operations and Organization (Policies)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation and Principles of Consolidation 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. Certain prior period amounts in the condensed consolidated financial statements and accompanying notes have been reclassified to conform to the current period’s presentation. 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 audited consolidated financial statements for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 15, 2019. Interim results are not necessarily indicative of results for a full year or any subsequent interim period. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all material adjustments consisting of a normal and recurring nature necessary to present fairly the Company’s financial position as of September 30, 2019 , results of operations, comprehensive income (loss) for the three and nine months ended September 30, 2019 and 2018 and cash flows for the nine months ended September 30, 2019 and 2018 .
Principles of Consolidation	Basis of Presentation and Principles of Consolidation 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. Certain prior period amounts in the condensed consolidated financial statements and accompanying notes have been reclassified to conform to the current period’s presentation. 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 audited consolidated financial statements for the year ended December 31, 2018 included in the Company’s Annual Report on Form 10-K filed with the SEC on March 15, 2019. Interim results are not necessarily indicative of results for a full year or any subsequent interim period. In the opinion of management, the accompanying unaudited condensed consolidated financial statements contain all material adjustments consisting of a normal and recurring nature necessary to present fairly the Company’s financial position as of September 30, 2019 , results of operations, comprehensive income (loss) for the three and nine months ended September 30, 2019 and 2018 and cash flows for the nine months ended September 30, 2019 and 2018 .
Use of Estimates	Use of Estimates In preparing the unaudited condensed consolidated financial statements, the Company uses 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 2019 and Recently Issued Accounting Standards Not Yet Adopted	Recently Adopted Accounting Standards - Guidance Adopted in 2019 In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-02, Leases (Topic 842), which primarily changes the lessee’s accounting for operating leases by requiring the recognition of lease right-of-use assets and lease liabilities. The guidance also eliminates previous real estate specific provisions. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842), Targeted Improvements, which amended the standard to give entities another option to apply the requirements of the standard in the period of adoption (January 1, 2019) or Effective Date Method. The Company adopted the new accounting guidance on January 1, 2019 using a modified retrospective approach reflecting the Effective Date Method of adoption in which the Company continued to apply the guidance in ASC 840, Leases to the comparable periods presented in the year of adoption. The Company made the following elections provided under the standard: • The package of practical expedients that permits the Company to retain its existing lease assessment and classification; • The practical expedient that allows the Company to not evaluate existing and expired land easements; • The practical expedient to not separate non-lease components in power purchase agreements (“PPAs”) in which the Company is the lessor in providing energy, capacity, and incentive products for a bundled fixed rate; and • The Company elected not to apply the recognition requirements for short-term operating leases, defined as a term of twelve months or shorter, from the commencement date. The Company evaluated the impact of Topic 842 as it relates to operating leases for land, buildings and equipment for which it is the lessee and reviewed its existing contracts for embedded leases. The adoption of the new standard resulted in the recognition of right-of-use assets and lease liabilities of approximately $252.7 million and $245.3 million , respectively, as of January 1, 2019 for operating leases, whereas the Company’s accounting for finance leases remained substantially unchanged. See Note 7. Leases for additional details. A significant portion of the Company’s operating revenues are generated from delivering electricity and related products from owned solar and wind renewable energy facilities under PPAs in which the Company is the lessor. Revenue is recognized when electricity is delivered and is accounted for as rental income under the lease standard. The adoption of ASC 842 did not have an impact on the accounting policy for rental income from the Company’s PPAs in which it is the lessor. The Company elected the package of practical expedients available under ASC 842, which did not require the Company to reassess its lease classification from ASC 840. Additionally, the Company elected the practical expedient to not separate lease and non-lease components for lessors. This election allows energy (lease component) and environmental incentives or renewable energy certificates (non-lease components) under bundled PPAs to be accounted as a singular lease unit of account under ASC 842. In October 2018, the FASB issued ASU No. 2018-16, Derivatives and Hedging (Topic 815): Inclusion of the Secured Overnight Financing Rate (“SOFR”) Overnight Index Swap (“OIS”) Rate as a Benchmark Interest Rate for Hedge Accounting Purposes. This ASU expands the list of United States (“U.S.”) benchmark interest rates permitted in the application of hedge accounting by adding the SOFR as a permissible U.S. benchmark rate. The Company does not have any derivative instruments indexed to SOFR as a benchmark interest rate, accordingly, the adoption of ASU No. 2018-16 as of January 1, 2019 did not have an impact on the Company’s consolidated financial statements. Recently Issued Accounting Standards Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses (Topic 326), to provide financial statement users with more useful information about expected credit losses. This ASU changes how entities measure credit losses on financial instruments and the timing of when such losses are recognized. The guidance is effective for fiscal years and interim periods within those years beginning after January 1, 2020, with early adoption permitted for periods beginning after December 15, 2018. The Company is currently evaluating the impact of this guidance on its consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement. This ASU removes some disclosure requirements, modifies others, and adds some new disclosure requirements. The guidance is effective January 1, 2020, with early adoption permitted. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40) Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract. This ASU amends the definition of a hosting arrangement and requires a customer in a cloud computing arrangement that is a service contract to follow the internal use software guidance in ASC 350-402 to determine which implementation costs to capitalize as assets. Capitalized implementation costs are amortized over the term of the hosting arrangement, beginning when the module or component of the hosting arrangement is ready for its intended use. The guidance is effective January 1, 2020, with early adoption permitted. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements. In October 2018, the FASB issued ASU No. 2018-17, Consolidation (Topic 810): Targeted Improvements to Related Party Guidance for Variable Interest Entities. The amendments in this ASU require reporting entities to consider indirect interests held through related parties under common control for determining whether fees paid to decision makers and service provider are variable interests. These indirect interests should be considered on a proportional basis rather than as the equivalent of a direct interest in its entirety (as currently required in U.S. GAAP). The guidance is effective January 1, 2020, with early adoption permitted. Entities are required to apply the amendments in this guidance retrospectively with a cumulative-effect adjustment to retained earnings at the beginning of the earliest period presented. The Company is currently evaluating the effect of the new guidance on its consolidated financial statements.
(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 (loss) income 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 represent the incremental shares issuable for unvested restricted 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	The Company has three reportable segments: Solar, Wind, and Regulated Solar and Wind. These segments, which represent the Company’s entire portfolio of renewable energy facilities, 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. Each of the Company’s reportable segments represent an aggregation of operating 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 (“CODM”) in deciding how to allocate resources. The Company’s Chief Executive Officer and Chief Financial Officer have been identified as the CODMs. The Company’s operating segments consist of: (i) Distributed Generation, North America Solar Utility, International Solar Utility, which are aggregated into the Solar reportable segment; (ii) Northeast Wind, Central Wind, Texas Wind, Hawaii Wind, Portugal Wind and Uruguay Wind operating segments, which are aggregated into the Wind reportable segment; and (iii) the Spanish Regulated Solar and Spanish Regulated Wind operating segments that are aggregated within the Regulated Solar and Wind reportable segment. Portugal Wind, Uruguay Wind, and the Spanish Regulated Solar and Wind segments were added during the second quarter of 2018 upon the acquisition of Saeta and represent its entire operations (see Note 4. Acquisitions for additional details). The operating segments have been aggregated as they have similar economic characteristics and meet the aggregation criteria. The CODMs evaluate the performance of the Company’s operating segments principally based on operating income or loss. Corporate expenses include general and administrative expenses, acquisition costs, interest expense on corporate-level indebtedness, stock-based compensation and depreciation expense. All net operating revenues for the three and nine months ended September 30, 2019 and 2018 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.

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table presents the Company’s operating revenues, net and disaggregated by revenue source: Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 (In thousands) Solar Wind Regulated Solar and Wind Total Solar Wind Regulated Solar and Wind Total PPA rental income $ 73,425 $ 31,532 $ — $ 104,957 $ 66,982 $ 35,084 $ — $ 102,066 Commodity derivatives — 10,453 — 10,453 — 7,469 — 7,469 PPA and market energy revenue 10,104 17,861 28,807 56,772 14,353 18,846 32,594 65,793 Capacity revenue from remuneration programs 1 — — 54,772 54,772 — — 47,356 47,356 Amortization of favorable and unfavorable rate revenue contracts, net (2,017 ) (7,774 ) — (9,791 ) (2,132 ) (7,779 ) — (9,911 ) Energy revenue 81,512 52,072 83,579 217,163 79,203 53,620 79,950 212,773 Incentive revenue 20,142 2,435 14,068 36,645 15,680 3,343 14,246 33,269 Operating revenues, net $ 101,654 $ 54,507 $ 97,647 $ 253,808 $ 94,883 $ 56,963 $ 94,196 $ 246,042 Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 (In thousands) Solar Wind Regulated Solar and Wind Total Solar Wind Regulated Solar and Wind Total PPA rental income $ 167,397 $ 135,670 $ — $ 303,067 $ 159,116 $ 138,396 $ — $ 297,512 Commodity derivatives — 42,560 — 42,560 — 39,917 — 39,917 PPA and market energy revenue 24,461 62,583 79,716 166,760 34,318 31,897 38,909 105,124 Capacity revenue from remuneration programs 1 — — 154,913 154,913 — — 59,327 59,327 Amortization of favorable and unfavorable rate revenue contracts, net (5,330 ) (23,315 ) — (28,645 ) (6,075 ) (23,403 ) — (29,478 ) Energy revenue 186,528 217,498 234,629 638,655 187,359 186,807 98,236 472,402 Incentive revenue 55,065 6,484 34,302 95,851 50,568 13,261 17,246 81,075 Operating revenues, net $ 241,593 $ 223,982 $ 268,931 $ 734,506 $ 237,927 $ 200,068 $ 115,482 $ 553,477 ——— (1) Represents the remuneration related on the Company’s investments in renewable energy facilities in Spain.

Acquisitions (Tables)

Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
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 September 30, 2019 were as follows: (In thousands) As of September 26, 2019 Renewable energy facilities in service 1 $ 545,085 Intangible assets 128,725 Accounts receivable 6,886 Prepaid expenses and other assets 7,978 Total assets acquired 688,674 Accounts payable, accrued expenses and other current liabilities 4,671 Asset retirement obligations 35,740 Operating lease liabilities 20,644 Other liabilities 7,007 Total liabilities assumed 68,062 Non-controlling interests 2 3,025 Purchase price, net of cash and restricted cash acquired 3 617,587 Deposit on acquisitions 114,195 Total cash paid for the WGL Acquisition, net of cash acquired $ 731,782 ——— (1) Includes $23.3 million operating lease right-of-use assets. (2) The fair value of the non-controlling interests was determined using an income approach representing the best indicator of fair value and was supported by a discounted cash flow technique. (3) The Company acquired cash and cash equivalents of $3.4 million as of the acquisition date. (In thousands) As of June 12, 2018, reported at December 31, 2018 Adjustments As of June 12, 2018, reported at June 30, 2019 Renewable energy facilities in service $ 1,993,520 $ (6,238 ) $ 1,987,282 Accounts receivable 91,343 — 91,343 Intangible Assets 1,034,176 (31,862 ) 1,002,314 Goodwill 123,106 32,283 155,389 Other assets 43,402 2,845 46,247 Total assets acquired 3,285,547 (2,972 ) 3,282,575 Accounts payable, accrued expenses and other current liabilities 93,032 (1,761 ) 91,271 Long-term debt, including current portion 1,906,831 16,139 1,922,970 Deferred income taxes 171,373 (17,256 ) 154,117 Asset retirement obligations 67,706 (94 ) 67,612 Derivative liabilities 137,002 — 137,002 Other long-term liabilities 23,002 — 23,002 Total liabilities assumed 2,398,946 (2,972 ) 2,395,974 Redeemable non-controlling interests 55,117 — 55,117 Purchase price, net of cash acquired $ 831,484 $ — $ 831,484 ——— (1) The excess purchase price over the estimated fair value of net assets acquired of $155.4 million was recorded as goodwill, with $117.4 million assigned to the Regulated Solar and Wind segment and $38.0 million assigned to the Wind segment. See Note 18. Segment Reporting for additional details on the Company’s segments. (2) The fair value of the non-controlling interests 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 was 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 the acquired intangible assets as of the acquisition date for Saeta. The Company attributed intangible asset value to concessions and licensing agreements in-place from solar and wind facilities. These intangible assets are amortized on a straight-line basis over the estimated remaining useful lives of the facilities from the Company’s acquisition date. As of June 12, 2018 Fair Value (In thousands) Weighted Average Amortization Period 1 Intangible assets - concession and licensing contracts $ 1,034,176 15 years ——— (1) For the 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. The following table summarizes the estimated fair values and the weighted average amortization periods of the acquired intangible assets and assumed intangible liabilities as of the acquisition date. The Company attributed the intangible asset values to favorable rate revenue contracts and PPAs in-place from renewable energy facilities and the intangible liabilities to unfavorable rate revenue contracts. WGL Acquisition Fair Value Weighted Average Amortization Period 1 Favorable rate revenue contracts $ 23,575 16 years In-place value of market rate revenue contracts 105,150 15 years Unfavorable rate revenue contracts 7,007 2 years ——— (1)
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, 2018. 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 nine months ended September 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. (In thousands) Nine Months Ended September 30, 2018 Total operating revenues, net $ 740,066 Net loss (108,314 ) The unaudited pro forma supplementary data presented in the table below gives effect to the WGL Acquisition, as if the transaction had occurred on January 1, 2018. The pro forma net loss includes interest expense related to incremental borrowings used to finance the transaction and adjustments to depreciation, accretion and amortization expense for the valuation of renewable energy facilities and intangible assets, and excludes the impact of acquisition 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. Nine Months Ended September 30, (In thousands) 2019 2018 Total operating revenues, net $ 790,403 $ 559,523 Net loss (71,099 ) 31,985

Cash and Cash Equivalents (Tabl

Cash and Cash Equivalents (Tables)	9 Months Ended
	Sep. 30, 2019
Cash and Cash Equivalents [Abstract]
Schedule of Restricted Cash and Cash Equivalents	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 nine months ended September 30, 2019 : (In thousands) September 30, December 31, Cash and cash equivalents $ 239,297 $ 248,524 Restricted cash - current 31,140 27,784 Restricted cash - non-current 73,794 116,501 Cash, cash equivalents and restricted cash shown in the unaudited condensed consolidated statement of cash flows $ 344,231 $ 392,809
Schedule of Cash and Cash Equivalents	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 nine months ended September 30, 2019 : (In thousands) September 30, December 31, Cash and cash equivalents $ 239,297 $ 248,524 Restricted cash - current 31,140 27,784 Restricted cash - non-current 73,794 116,501 Cash, cash equivalents and restricted cash shown in the unaudited condensed consolidated statement of cash flows $ 344,231 $ 392,809

Renewable Energy Facilities (Ta

Renewable Energy Facilities (Tables)	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Renewable Energy Facilities	Renewable energy facilities, net consisted of the following: (In thousands) September 30, December 31, Renewable energy facilities in service, at cost 1 $ 8,037,096 $ 7,298,371 Less: accumulated depreciation (1,080,363 ) (833,844 ) Renewable energy facilities in service, net 6,956,733 6,464,527 Construction in progress - renewable energy facilities 10,416 5,499 Total renewable energy facilities, net $ 6,967,149 $ 6,470,026 ——— (1) As discussed in Note 2. Summary of Significant Accounting Policies and Note 7. Leases , on January 1, 2019, the Company recognized $252.7 million right-of-use of assets related to operating leases as a result of the adoption of Topic 842, which is included within renewable energy facilities. The amount of right-of-use of assets as of September 30, 2019, including the effect of acquisitions, was $269.3 million .

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Components of Lease Expense and Supplemental Cash Flow Information	The components of lease expense were as follows: (In thousands) Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Fixed operating lease cost $ 4,740 $ 15,936 Variable operating lease cost 1 834 3,239 Total operating lease cost $ 5,574 $ 19,175 ——— (1) Primarily related to production-based variable inputs and adjustments for inflation. Supplemental cash flow information related to the Company’s leases was as follows: (In thousands) Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases 1 $ 5,472 $ 11,487 ——— (1) Right-of-use assets, excluding the effect of acquisitions, obtained in exchange for lease obligations for the nine months ended September 30, 2019 , were not material.
Supplemental Balance Sheet Information	Supplemental balance sheet information related to the Company’s leases was as follows: (In thousands, except lease term and discount rate) As of September 30, 2019 Operating leases: Right-of-use assets $ 269,309 Accounts payable, accrued expenses and other current liabilities $ 14,980 Operating lease obligations, less current portion 255,507 Total operating lease liabilities $ 270,487 Weighted Average Remaining Lease Term: Operating leases 18 years Weighted Average Discount Rate: Operating leases 4.5%
Maturities of Lease Liabilities	aturities of the Company’s operating lease liabilities by fiscal year were as follows: (In thousands) Remainder of 2019 $ 10,417 2020 21,280 2021 21,566 2022 21,434 2023 22,073 Thereafter 324,230 Total lease payments 421,000 Less: Imputed interest (150,513 ) Total $ 270,487

Intangible Assets, Net and Go_2

Intangible Assets, Net and Goodwill (Tables)	9 Months Ended
	Sep. 30, 2019
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 September 30, 2019 : (In thousands, except weighted average amortization period) Weighted Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Book Value Concession and licensing contracts 14 years $ 948,740 $ (83,182 ) $ 865,558 Favorable rate revenue contracts 13 years 746,126 (184,983 ) 561,143 In-place value of market rate revenue contracts 17 years 651,239 (120,794 ) 530,445 Total intangible assets, net $ 2,346,105 $ (388,959 ) $ 1,957,146 Unfavorable rate revenue contracts 6 years $ 47,777 $ (30,304 ) $ 17,473 Unfavorable rate operations and maintenance contracts 3 months 5,000 (4,770 ) 230 Total intangible liabilities, net 1 $ 52,777 $ (35,074 ) $ 17,703 ——— (1) The Company’s intangible liabilities are classified within other long-term liabilities in the unaudited condensed consolidated balance sheets. The following table presents the gross carrying amount, accumulated amortization and net book value of intangibles as of December 31, 2018 : (In thousands, except weighted average amortization period) Weighted Average Amortization Period Gross Carrying Amount Accumulated Amortization Net Book Value Concession and licensing contracts 15 years $ 1,015,824 $ (36,374 ) $ 979,450 Favorable rate revenue contracts 14 years 738,488 (166,507 ) 571,981 In-place value of market rate revenue contracts 18 years 532,844 (100,543 ) 432,301 Favorable rate land leases 1 16 years 15,800 (3,128 ) 12,672 Total intangible assets, net $ 2,302,956 $ (306,552 ) $ 1,996,404 Unfavorable rate revenue contracts 6 years $ 58,508 $ (41,605 ) $ 16,903 Unfavorable rate operations and maintenance contracts 1 year 5,000 (3,802 ) 1,198 Unfavorable rate land lease 1 14 years 1,000 (218 ) 782 Total intangible liabilities, net 2 $ 64,508 $ (45,625 ) $ 18,883 ——— (1) On January 1, 2019, these amounts were reclassified to right-of-use assets in connection with the adoption of Topic 842. See Note 2. Summary of Significant Accounting Policies and Note 7. Leases for additional details. (2) The Company’s intangible liabilities are classified within other long-term liabilities in the unaudited condensed consolidated balance sheets.
Goodwill	Goodwill Goodwill represents the excess of the consideration transferred and fair value of the non-controlling interests over the fair values of assets acquired and liabilities assumed from business combinations, and reflects the future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. The goodwill balance is not deductible for income tax purposes. The following table presents the activity of the goodwill balance for the nine months ended September 30, 2019 and the year ended December 31, 2018: (In thousands) September 30, December 31, Beginning balance $ 120,553 $ — Goodwill resulting from business combinations 1 — 115,381 Adjustments during the period 2 32,283 7,726 Foreign exchange differences (7,220 ) (2,554 ) Ending balance $ 145,616 $ 120,553 ——— (1) Represents the excess purchase price over the estimated fair value of net assets acquired from Saeta and is primarily attributable to deferred tax liabilities and adjustment to the fair value of certain project long-term debt. See Note 4. Acquisitions for additional details. (2) Represents the adjustments to the goodwill balance arising from the revision of the provisional accounting of Saeta’s purchase price allocation.

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	9 Months Ended
	Sep. 30, 2019
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 assets and liabilities of the VIEs included in the Company’s unaudited condensed consolidated balance sheets were as follows: (In thousands) September 30, December 31, Current assets $ 134,551 $ 134,057 Non-current assets 4,032,239 3,909,549 Total assets $ 4,166,790 $ 4,043,606 Current liabilities $ 319,738 $ 120,790 Non-current liabilities 949,812 1,014,789 Total liabilities $ 1,269,550 $ 1,135,579

Long-term Debt (Tables)

Long-term Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of Debt	Long-term debt consists of the following: (In thousands, except interest rates) September 30, December 31, Interest Type Interest Rate (%) 1 Financing Type Corporate-level long-term debt 2 : Senior Notes due 2023 $ 500,000 $ 500,000 Fixed 4.25 Senior notes Senior Notes due 2025 3 300,000 300,000 Fixed 6.63 Senior notes Senior Notes due 2028 700,000 700,000 Fixed 5.00 Senior notes Revolver 4 356,000 377,000 Variable 4.27 Revolving loan Term Loan 3,5 343,875 346,500 Variable 4.04 Term debt Non-recourse long-term debt: Permanent financing 3,557,646 3,496,370 Blended 7 4.55 8 Term debt / Senior notes Bridge Facility 6 475,000 — Variable 3.09 Term debt Financing obligations 62,200 77,066 Imputed 5.85 8 Financing lease obligations Total principal due for long-term debt and financing obligations 6,294,721 5,796,936 4.53 8 Unamortized premiums and discounts, net 3,758 (15,913 ) Deferred financing costs, net (38,036 ) (19,178 ) Less: current portion of long-term debt and financing lease obligations (635,929 ) (464,332 ) Long-term debt and financing obligations, less current portion $ 5,624,514 $ 5,297,513 ——— (1) As of September 30, 2019 . (2) Represents the debt issued by TerraForm Power Operating, LLC (“Terra Operating LLC”) and guaranteed by Terra LLC and certain subsidiaries of TerraForm Operating LLC other than non-recourse subsidiaries as defined in the relevant debt agreements (except for certain unencumbered non-recourse subsidiaries). (3) Subsequent to quarter end, on October 16, 2019, Terra Operating LLC issued $700.0 million of 4.75% senior notes due on January 15, 2030 at an offering price of 100% of the principal amount. The proceeds from the notes were used to redeem, in full, the Company’s existing Senior Notes due 2025 and Term Loan (as defined below). See Note 21. Subsequent Events for additional details. (4) Represents the amounts outstanding under the Terra Operating LLC senior secured revolving credit facility (the “Revolver”). Subsequent to quarter end, on October 8, 2019, the Company entered into an amendment whereby it, among other things, increased the aggregate lending commitment by $200.0 million . See Note 21. Subsequent Events for additional details. As of October 31, 2019, the Company repaid most the outstanding balance under the Revolver. (5) Represents the amounts outstanding under Terra Operating LLC’s senior secured term loan facility (the “Term Loan”). Subsequent to quarter end, on October 16, 2019 , the Company redeemed the entire outstanding balance. See Note 21. Subsequent Events for additional details. (6) Represents senior secured term debt issued to fund a portion of the consideration paid for the WGL Acquisition. See below for additional details. (7) Includes fixed and variable rate debt. As of September 30, 2019 , 36 % of this balance had a fixed interest rate and the remaining 64 % of this balance had a variable interest rate. The Company entered into interest rate swap agreements to fix the interest rates of the majority of the variable rate permanent financing non-recourse debt (see Note 12. Derivatives for additional details). (8) Represents the weighted-average interest rate as of September 30, 2019 .
Aggregate Contractual Payments of Long-term Debt	The aggregate contractual principal payments of long-term debt due after September 30, 2019 , excluding the amortization of debt discounts, premiums and deferred financing costs, as stated in the financing agreements, are as follows: (In thousands) Remainder of 2019 2020 2 2021 2022 2023 Thereafter Total Maturities of long-term debt 1 $ 96,852 $ 732,185 $ 269,528 $ 770,751 $ 1,220,271 $ 3,205,134 $ 6,294,721 ——— (1) Represents the contractual principal payment due dates for the Company’s long-term debt and does not reflect the reclassification of $387.8 million of long-term debt, net of unamortized deferred financing costs and debt discounts, to current due to debt defaults that existed as of the date of the issuance of the financial statements (see above for additional details). (2) Includes the $475.0 million Bridge Facility maturing on September 23, 2020. The Company has a one-year extension option and intends, through its subsidiaries, to complete a refinancing of the balance on a long-term basis prior to maturity. The balance, net of unamortized deferred financing costs, is included within non-current liabilities in the unaudited condensed consolidated balance sheets.

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Components of Income Tax Provision	The income tax provision consisted of the following: Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except effective tax rate) 2019 2018 2019 2018 Loss before income tax expense $ (60,801 ) $ (13,038 ) $ (112,167 ) $ (113,559 ) Income tax expense 1,512 6,013 3,030 9,417 Effective tax rate (2.5 )% (46.1 )% (2.7 )% (8.3 )%

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2019
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Fair Values of Derivative Instruments	As of September 30, 2019 and December 31, 2018 , the fair values of the following derivative instruments were included in the respective balance sheet captions indicated below: Fair Value of Derivative Instruments 1 Derivatives Designated as Hedging Instruments Derivatives Not Designated as Hedging Instruments (In thousands) Interest Rate Swaps Foreign Currency Contracts Commodity Contracts Interest Rate Swaps Foreign Currency Contracts Commodity Contracts Gross Derivatives Counterparty Netting 2 Net Derivatives As of September 30, 2019 Derivative assets, current $ — $ 1,217 $ 365 $ — $ 19,365 $ 8,069 $ 29,016 $ (108 ) $ 28,908 Derivative assets — 9,831 41,679 — 4,346 42,019 97,875 (779 ) 97,096 Total assets $ — $ 11,048 $ 42,044 $ — $ 23,711 $ 50,088 $ 126,891 $ (887 ) $ 126,004 Derivative liabilities, current portion $ 5,717 $ 108 $ — $ 33,012 $ — $ — $ 38,837 $ (108 ) $ 38,729 Derivative liabilities 35,585 4 — 105,570 775 — 141,934 (779 ) 141,155 Total liabilities $ 41,302 $ 112 $ — $ 138,582 $ 775 $ — $ 180,771 $ (887 ) $ 179,884 As of December 31, 2018 Derivative assets, current $ 1,478 $ 605 $ 18 $ — $ 3,344 $ 9,783 $ 15,228 $ (857 ) $ 14,371 Derivative assets 5,818 2,060 42,666 — 647 40,137 91,328 (344 ) 90,984 Total assets $ 7,296 $ 2,665 $ 42,684 $ — $ 3,991 $ 49,920 $ 106,556 $ (1,201 ) $ 105,355 Derivative liabilities, current portion $ 465 $ — $ — $ 34,267 $ 1,684 $ — $ 36,416 $ (857 ) $ 35,559 Derivative liabilities 3,334 1,437 — 88,034 1,387 — 94,192 (344 ) 93,848 Total liabilities $ 3,799 $ 1,437 $ — $ 122,301 $ 3,071 $ — $ 130,608 $ (1,201 ) $ 129,407 ———— (1) Fair value amounts are shown before the effect of counterparty netting adjustments. (2) Represents the netting of derivative exposures covered by qualifying master netting arrangements.
Schedule of Notional Amounts for Derivative Instruments	of September 30, 2019 and December 31, 2018 : Notional Amount as of (In thousands) September 30, 2019 December 31, 2018 Derivatives designated as hedging instruments: Cash flow hedges: Interest rate swaps (USD) 867,184 357,797 Interest rate swaps (CAD) 139,075 147,522 Commodity contracts (MWhs) 5,528 6,030 Net investment hedges: Foreign currency contracts (CAD) 94,100 81,600 Foreign currency contracts (EUR) 200,000 320,000 Derivatives not designated as hedging instruments: Interest rate swaps (USD) 11,616 12,326 Interest rate swaps (EUR) 1 991,942 1,044,253 Foreign currency option contracts (EUR) 2 625,200 — Foreign currency forward contracts (EUR) 2 165,000 640,200 Foreign currency contracts (CAD) 7,800 — Commodity contracts (MWhs) 7,895 8,707 ———— (1) Represents the notional amount of the interest rate swaps at Saeta to economically hedge the interest payments on non-recourse debt. The Company did not designate these derivatives as hedging instruments under ASC 815 as of September 30, 2019 and December 31, 2018 . (2) Represents the notional amount of foreign currency contracts used to economically hedge a portion of the Company’s foreign exchange risk associated with Euro-denominated intercompany loans. The Company did not designate these derivatives as hedging instruments under ASC 815 as of September 30, 2019 and December 31, 2018 .
Gains and Losses on Derivatives Not Designated As Hedges	Gains and losses on derivatives not designated as hedging instruments for the three and nine months ended September 30, 2019 and 2018 consisted of the following: Location of Loss (Gain) in the Statements of Operations Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2019 2018 2019 2018 Interest rate swaps Interest expense, net $ 20,911 $ 4,737 $ 50,189 $ (3,252 ) Foreign currency contracts Loss (gain) on foreign currency exchange, net (19,667 ) (4,348 ) (39,596 ) (16,914 ) Commodity contracts Operating revenues, net 307 (3,880 ) (13,311 ) (21,374 )
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, foreign currency contracts and commodity derivative contracts designated as hedging instruments for the three and nine months ended September 30, 2019 and 2018 consisted of the following: Three Months Ended September 30, Derivatives in Cash Flow and Net Investment Hedging Relationships (Loss) Gain 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 Location of Amount Reclassified from AOCI into Income Loss (Gain) Included in the Assessment of Effectiveness Reclassified from AOCI into Income 2 Gain Excluded from the Assessment of Effectiveness that is Amortized through Earnings (In thousands) 2019 2018 2019 2018 2019 2018 2019 2018 Interest rate swaps $ (14,722 ) $ 4,107 $ — $ — Interest expense, net $ 128 $ 263 $ — $ — Foreign currency contracts 11,915 3,549 — — Loss on foreign currency exchange, net — — — — Commodity contracts (6,760 ) 4,645 — — Operating revenues, net 4,794 (5,019 ) — (251 ) Total $ (9,567 ) $ 12,301 $ — $ — $ 4,922 $ (4,756 ) $ — $ (251 ) ———— (1) Net of $2,506 tax benefit attributed to interest rate swaps recorded for the three months ended September 30, 2019 . No tax expense or benefit was recorded for the three months ended September 30, 2018 . (2) No tax expense or benefit was recorded for the three months ended September 30, 2019 and 2018 . Nine Months Ended September 30, Derivatives in Cash Flow and Net Investment Hedging Relationships (Loss) Gain 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 Location of Amount Reclassified from AOCI into Income Loss (Gain) Included in the Assessment of Effectiveness Reclassified from AOCI into Income 2 (Gain) Excluded from the Assessment of Effectiveness that is Amortized through Earnings (In thousands) 2019 2018 2019 2018 2019 2018 2019 2018 Interest rate swaps $ (41,336 ) $ 14,627 $ — $ — Interest expense, net $ (867 ) $ 1,236 $ — $ — Foreign currency contracts 20,191 3,549 — — (Gain) on foreign currency exchange, net — — — — Commodity contracts (2,605 ) (2,834 ) — 735 Operating revenues, net 4,116 (7,061 ) — (930 ) Total $ (23,750 ) $ 15,342 $ — $ 735 $ 3,249 $ (5,825 ) $ — $ (930 ) ———— (1) Net of $2,506 tax benefit attributed to interest rate swaps recorded for the nine months ended September 30, 2019 . No tax expense or benefit was recorded for the nine months ended September 30, 2018 . (2) No tax expense or benefit attributed to interest rate swaps was recorded for the nine months ended September 30, 2019 and 2018 .

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
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: As of September 30, 2019 As of December 31, 2018 (In thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Interest rate swaps $ — $ — $ — $ — $ — $ 7,296 $ — $ 7,296 Commodity contracts — 7,553 84,579 92,132 — 12,816 79,788 92,604 Foreign currency contracts — 33,872 — 33,872 — 5,455 — 5,455 Total derivative assets $ — $ 41,425 $ 84,579 $ 126,004 $ — $ 25,567 $ 79,788 $ 105,355 Liabilities Interest rate swaps $ — $ 179,884 $ — $ 179,884 $ — $ 126,100 $ — $ 126,100 Foreign currency contracts — — — — — 3,307 — 3,307 Total derivative liabilities $ — $ 179,884 $ — $ 179,884 $ — $ 129,407 $ — $ 129,407
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 nine months ended September 30, 2019 and 2018 : Three Months Ended September 30, Nine Months Ended September 30, (In thousands) 2019 2018 2019 2018 Beginning balance $ 86,079 $ 81,859 $ 79,652 $ 80,268 Realized and unrealized gains (losses): Included in other comprehensive (loss) income (6,760 ) 418 (2,605 ) (10,090 ) Included in operating revenues, net (2,295 ) 1,324 3,793 16,873 Settlements 7,555 583 3,739 (2,867 ) Ending balance $ 84,579 $ 84,184 $ 84,579 $ 84,184
Significant Unobservable Inputs Used in Valuation of Commodity Contracts	The significant unobservable inputs used in the valuation of the Company’s commodity contracts classified as Level 3 in the fair value hierarchy as of September 30, 2019 are as follows: (In thousands, except range) Fair Value as of Transaction Type Assets Liabilities Valuation Technique Unobservable Inputs as of September 30, 2019 Commodity contracts - power $ 84,579 $ — Option model Volatilities 14.5% Range Discounted cash flow Forward price (per MWh) $7.15 - $177.20
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 September 30, 2019 and December 31, 2018 was follows: As of September 30, 2019 As of December 31, 2018 (In thousands) Carrying Amount Fair Value Carrying Amount Fair Value Long-term debt $ 6,260,443 $ 6,521,099 $ 5,761,845 $ 5,789,702

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Schedule of Common Stock Outstanding Roll Forward	The following table reflects the changes in the Company’s shares of Common Stock outstanding during the nine months ended September 30, 2019 and 2018 : Nine Months Ended September 30, (In thousands) 2019 2018 Balance as of January 1 209,142 148,086 Issuance of Common Stock to affiliates 1 — 61,056 Net shares issued under equity incentive plan 13 — Balance as of September 30 209,155 209,142 ——— (1) On June 11, 2018, the Company completed a private placement of 60,975,609 shares of the Company’s Common Stock with affiliates of Brookfield at a price of $10.66 per share for a total consideration of $650.0 million . The proceeds of the offering were used to pay a portion of the purchase price of the Tendered Shares of Saeta. On August 3, 2018, the Company issued 80,084 shares of Common Stock to an affiliate of Brookfield in connection with the net losses incurred, such as out-of-pocket losses, damages, costs, fees and expenses, in connection with the obtainment of a final resolution of a certain litigation matter.
Schedule of Restricted Stock Units	The following table presents information regarding outstanding RSUs as of September 30, 2019 and changes during the nine months ended September 30, 2019 : Number of RSUs Outstanding Weighted- Average Exercise Price Aggregate Intrinsic Value (in thousands) Weighted Average Remaining Balance as of January 1, 2019 103,300 $ 11.15 Granted 156,550 12.17 Vested (20,878 ) 11.15 Forfeited (38,406 ) 11.65 Balance as of September 30, 2019 200,566 $ 11.85 $ 3,861.2 1.6 years
Dividends Declared	The following table presents the cash distributions declared and paid on Common Stock during the nine months ended September 30, 2019 and 2018 : Distributions per Share Declaration Date Record Date Payment Date 2019: First Quarter $ 0.2014 March 13, 2019 March 24, 2019 March 29, 2019 Second Quarter 0.2014 May 8, 2019 June 3, 2019 June 17, 2019 Third Quarter 0.2014 August 8, 2019 September 3, 2019 September 17, 2019 2018: 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 Third Quarter 0.19 August 13, 2018 September 1, 2018 September 15, 2018

(Loss) Earnings Per Share (Tabl

(Loss) Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
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 Common Stock for the three and nine months ended September 30, 2019 and 2018 was calculated as follows: Three Months Ended September 30, Nine Months Ended September 30, (In thousands, except per share amounts) 2019 2018 2019 2018 Basic and diluted (loss) earnings per share: Net (loss) income attributable to Class A common stockholders $ (54,837 ) $ (33,590 ) $ (67,059 ) $ 27,869 Weighted average basic Class A shares outstanding 1 209,155 209,142 209,149 173,173 Weighted average diluted Class A shares outstanding 2 209,155 209,142 209,149 173,186 Basic and diluted (loss) earnings per share $ (0.26 ) $ (0.16 ) $ (0.32 ) $ 0.16 ——— (1) The weighted-average basic Class A shares outstanding for the nine months ended September 30, 2018 included 66 thousand contingently issuable shares. There were no contingently issuable shares for the three months ended September 30, 2018. (2) The computation of diluted earnings per share of the Company’s Common Stock for the nine months ended September 30, 2019 excluded 36 thousand of potentially dilutive unvested RSUs, respectively, because the effect would have been anti-dilutive. The computation of diluted loss per share of the Company’s Common Stock for the three months ended September 30, 2018, excludes 103 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 Common Stock for the nine months ended September 30, 2018, includes 13 thousand of RSUs considered to be dilutive and calculated using the treasury stock method.

Segment Reporting (Tables)

Segment Reporting (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Summarized Financial Information of Reportable Segments	The following table reflects summarized financial information regarding the Company’s reportable segments for the three and nine months ended September 30, 2019 and 2018 : Three Months Ended September 30, 2019 Three Months Ended September 30, 2018 (In thousands) Solar 1 Wind Regulated Solar and Wind Corporate Total Solar Wind Regulated Solar and Wind Corporate Total Operating revenues, net $ 101,654 $ 54,507 $ 97,647 $ — $ 253,808 $ 94,883 $ 56,963 $ 94,196 $ — $ 246,042 Depreciation, accretion and amortization expense 29,753 49,052 34,957 520 114,282 28,299 40,992 33,954 348 103,593 Other operating costs and expenses 9,912 38,120 28,085 23,044 99,161 11,109 31,302 24,971 18,401 85,783 Operating income (loss) 61,989 (32,665 ) 34,605 (23,564 ) 40,365 55,475 (15,331 ) 35,271 (18,749 ) 56,666 Interest expense, net 17,302 16,220 27,073 28,798 89,393 15,992 14,367 9,632 32,425 72,416 Other non-operating expenses (income), net 428 (132 ) 599 10,878 11,773 632 (347 ) (727 ) (2,270 ) (2,712 ) Income tax expense 3,653 401 (2,543 ) 1 1,512 749 927 2,268 2,069 6,013 Net income (loss) $ 40,606 $ (49,154 ) $ 9,476 $ (63,241 ) $ (62,313 ) $ 38,102 $ (30,278 ) $ 24,098 $ (50,973 ) $ (19,051 ) Nine Months Ended September 30, 2019 Nine Months Ended September 30, 2018 (In thousands) Solar Wind Regulated Solar and Wind 1 Corporate Total Solar 3 Wind Regulated Solar and Wind 1 Corporate Total Operating revenues, net $ 241,593 $ 223,982 $ 268,931 $ — $ 734,506 $ 237,927 $ 200,068 $ 115,482 $ — $ 553,477 Depreciation, accretion and amortization expense 84,829 132,694 102,955 1,127 321,605 83,041 113,926 41,148 1,062 239,177 Impairment of renewable energy facilities — — — — — 15,240 — — — 15,240 Other operating costs and expenses 41,274 113,585 66,791 66,854 288,504 39,792 89,834 30,012 77,506 237,144 Operating income (loss) 115,490 (22,297 ) 99,185 (67,981 ) 124,397 99,854 (3,692 ) 44,322 (78,568 ) 61,916 Interest expense, net 46,693 45,173 65,539 89,316 246,721 46,248 36,382 4,879 89,353 176,862 Other non-operating (income) expenses, net (6,391 ) (550 ) 449 (3,665 ) (10,157 ) (1,926 ) 538 (617 ) 618 (1,387 ) Income tax expense 1,532 830 553 115 3,030 749 1,291 4,442 2,935 9,417 Net income (loss) $ 73,656 $ (67,750 ) $ 32,644 $ (153,747 ) $ (115,197 ) $ 54,783 $ (41,903 ) $ 35,618 $ (171,474 ) $ (122,976 ) Balance Sheet Total assets 2,3 3,587,474 3,762,649 2,496,186 82,882 $ 9,929,191 2,762,977 3,733,049 2,748,126 86,202 $9,330,354 ——— (1) The Company’s Regulated Solar and Wind segment and wind operations in Portugal and Uruguay were added in the second quarter of 2018 upon acquiring a controlling interest in Saeta. See Note 4. Acquisitions for additional details. (2) Total assets within the Solar reporting segment as of September 30, 2019 include $693.9 million of assets from the WGL Acquisition that was completed on September 26, 2019. See Note 4. Acquisitions for additional details. (3) Represents total assets as of September 30, 2019 and December 31, 2018 , respectively.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Changes in Accumulated Other Comprehensive (Loss) 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, 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) income: Net unrealized (loss) gain arising during the period (net of zero tax impact) (8,229 ) 12,528 4,299 Reclassification of net realized gain into earnings (net of zero tax impact) — (6,755 ) (6,755 ) Other comprehensive (loss) income (8,229 ) 5,773 (2,456 ) Accumulated other comprehensive (loss) income (21,641 ) 63,039 41,398 Less: Other comprehensive loss attributable to non-controlling interests — (3,038 ) (3,038 ) Balance as of September 30, 2018 $ (21,641 ) $ 66,077 $ 44,436 (In thousands) Foreign Currency Translation Adjustments Hedging Activities 1 Accumulated Other Comprehensive Income Balance as of December 31, 2018 $ (8,405 ) $ 48,643 $ 40,238 Other comprehensive (loss) income: Net unrealized gain (loss) arising during the period (net of zero and $2,506 tax benefit, respectively) 15,806 (43,941 ) (28,135 ) Reclassification of net realized gain into earnings (net of zero tax impact) — (2,439 ) (2,439 ) Other comprehensive income (loss) 15,806 (46,380 ) (30,574 ) Accumulated other comprehensive income 7,401 2,263 9,664 Less: Other comprehensive income attributable to non-controlling interests — 920 920 Balance as of September 30, 2019 $ 7,401 $ 1,343 $ 8,744 ——— (1) See Note 12. Derivatives for additional breakout of hedging gains and losses for interest rate swaps and commodity contracts in a cash flow hedge relationship and the foreign currency contracts designated as hedges of net investments in foreign operations. (2) Represents the impact of the adoption of ASU No. 2017-12 as of January 1, 2018.

Non-controlling Interests (Tabl

Non-controlling Interests (Tables)	9 Months Ended
	Sep. 30, 2019
Noncontrolling Interest [Abstract]
Activity of Redeemable Non-controlling Interests	The following table presents the activity of the redeemable non-controlling interests balance for the nine months ended September 30, 2019 and 2018: Nine Months Ended September 30, (In thousands) 2019 2018 Balance as of January 1 $ 33,495 $ 34,660 Cumulative-effect adjustment 1 — (4,485 ) Net loss (14,241 ) 15,101 Distributions (852 ) (1,993 ) Repurchases of redeemable non-controlling interests, net 2 (4,753 ) 617 Non-cash redemption of redeemable non-controlling interests 7,345 — Balance as of September 30 $ 20,994 $ 43,900 ——— (1) Represents the effect from the adoption of ASU No. 2014-09 and ASU No. 2016-08 as of January 1, 2018. (2) See below for additional details.

Nature of Operations and Orga_3

Nature of Operations and Organization (Details) - Affiliates of Brookfield	Oct. 08, 2019	Sep. 30, 2019
TerraForm Power | Share Purchase Agreement
Noncontrolling Interest [Line Items]
Percentage of ownership		65.00%
Subsequent Event
Noncontrolling Interest [Line Items]
Percentage of ownership	61.00%
Subsequent Event | TerraForm Power
Noncontrolling Interest [Line Items]
Percentage of ownership	61.00%

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets	$ 269,309
Lease liabilities	$ 270,487
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets		$ 252,700
Lease liabilities		$ 245,300

Revenue (Details)

Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	$ 253,808	$ 246,042	$ 734,506	$ 553,477
Amortization of favorable and unfavorable rate revenue contracts, net	(9,791)	(9,911)	(28,645)	(29,478)
Contract liability	8,500		8,500		$ 8,800
Performance obligation	3,200		3,200		$ 4,900
Contract with customer liability revenue recognized	400		1,700
Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	101,654	94,883	241,593	237,927
Amortization of favorable and unfavorable rate revenue contracts, net	(2,017)	(2,132)	(5,330)	(6,075)
Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	54,507	56,963	223,982	200,068
Amortization of favorable and unfavorable rate revenue contracts, net	(7,774)	(7,779)	(23,315)	(23,403)
Regulated Solar and Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	97,647	94,196	268,931	115,482
Amortization of favorable and unfavorable rate revenue contracts, net	0	0	0	0
PPA rental income
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	104,957	102,066	303,067	297,512
PPA rental income | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	73,425	66,982	167,397	159,116
PPA rental income | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	31,532	35,084	135,670	138,396
PPA rental income | Regulated Solar and Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	0	0	0	0
Commodity derivatives
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	10,453	7,469	42,560	39,917
Commodity derivatives | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	0	0	0	0
Commodity derivatives | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	10,453	7,469	42,560	39,917
Commodity derivatives | Regulated Solar and Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	0	0	0	0
PPA and market energy revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	56,772	65,793	166,760	105,124
PPA and market energy revenue | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	10,104	14,353	24,461	34,318
PPA and market energy revenue | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	17,861	18,846	62,583	31,897
PPA and market energy revenue | Regulated Solar and Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	28,807	32,594	79,716	38,909
Capacity revenue from remuneration programs
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	54,772	47,356	154,913	59,327
Capacity revenue from remuneration programs | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	0	0	0	0
Capacity revenue from remuneration programs | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	0	0	0	0
Capacity revenue from remuneration programs | Regulated Solar and Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	54,772	47,356	154,913	59,327
Energy revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	217,163	212,773	638,655	472,402
Energy revenue | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	81,512	79,203	186,528	187,359
Energy revenue | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	52,072	53,620	217,498	186,807
Energy revenue | Regulated Solar and Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	83,579	79,950	234,629	98,236
Incentive revenue
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	36,645	33,269	95,851	81,075
Incentive revenue | Solar
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	20,142	15,680	55,065	50,568
Incentive revenue | Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	2,435	3,343	6,484	13,261
Incentive revenue | Regulated Solar and Wind
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Operating revenues, net	$ 14,068	$ 14,246	$ 34,302	$ 17,246

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details)	Oct. 31, 2019USD ($)projectMW	Sep. 26, 2019USD ($)MW	Jul. 02, 2018USD ($)	Jun. 12, 2018USD ($)	Jun. 11, 2018USD ($)	Dec. 31, 2019USD ($)MW	Sep. 30, 2019USD ($)MW	Sep. 30, 2018USD ($)MW	Sep. 30, 2019USD ($)businessMW	Sep. 30, 2018USD ($)businessMW	Nov. 12, 2019USD ($)	Nov. 08, 2019USD ($)	Sep. 25, 2019USD ($)MW	Jul. 19, 2019USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2018USD ($)	Jun. 08, 2018	Feb. 07, 2018€ / sharesMW
Business Acquisition [Line Items]
Deposit on acquisitions							$ 114,195,000		$ 114,195,000							$ 0
Payments to acquired assets									18,255,000	$ 4,105,000
Proceeds from the private placement of its Class A common stock				$ 650,000,000	$ 650,000,000				0	650,000,000
Borrowings				471,000,000
Acquisition costs related to affiliates							$ 0	$ 300,000	$ 0	$ 7,000,000
WGL Acquisition
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW		320					18		18
Purchase price		$ 720,000,000
Purchase price, working capital		$ 15,100,000
Capacity of power plant, delayed | MW		34.8
Deposit on acquisitions		$ 114,195,000												$ 114,200,000
Saeta Yield
Business Acquisition [Line Items]
Purchase price			$ 54,600,000	$ 1,120,000,000
Percentage acquired			4.72%	95.28%														100.00%
Share price (in euros per share) | € / shares																		€ 12.20
Percentage of voting interests accepted to be acquired																	95.00%
Project-level debt assumed				$ 1,910,000,000											$ 1,922,970,000	$ 1,906,831,000
Cash on hand paid for acquisition				82,000,000
Operating revenues of acquiree							$ 113,100,000		$ 318,400,000
Net income of acquiree							$ 7,600,000		$ 33,700,000
Capacity revenue from remuneration programs | Saeta Yield
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW																		1,028
Wind | Saeta Yield
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW																		250
Solar1 | Saeta Yield
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW																		778
Sponsor Line | Revolving Credit Facility
Business Acquisition [Line Items]
Borrowings				30,000,000
Revolver | Revolving Credit Facility
Business Acquisition [Line Items]
Borrowings				$ 359,000,000
Solar Distributed Generation Portfolio
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW							10.6	6.1	10.6	6.1
Number of assets acquired | business									3	6
Payments to acquired assets									$ 18,300,000	$ 4,100,000
Forecast | Solar Distributed Generation Portfolio
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW						4.5
Payments to acquired assets						$ 6,000,000
Bridge Facility
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW													320
Face amount of debt instrument													$ 475,000,000
Bridge Facility | WGL Acquisition
Business Acquisition [Line Items]
Face amount of debt instrument		$ 475,000,000
Subsequent Event | WGL Acquisition
Business Acquisition [Line Items]
Nameplate capacity (MW) | MW	18
Deposit on acquisitions											$ 45,400,000	$ 45,400,000
Number of projects transferred to company | project	43
Release From Escrow	$ 68,800,000

Acquisitions - Allocation of Ac

Acquisitions - Allocation of Acquisition-Date Fair Value of Assets, Liabilities and Non-controlling Interests (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 26, 2019	Jul. 19, 2019	Dec. 31, 2018	Jun. 12, 2018	Dec. 31, 2017
As Reported
Goodwill		$ 145,616	$ 120,553			$ 120,553		$ 0
Deposit on acquisitions		114,195				0
Adjustments
Goodwill		32,283	$ 7,726
Right-of-use assets		269,309
WGL Acquisition
As Reported
Renewable energy facilities in service				$ 545,085
Intangible assets				128,725
Accounts receivable				6,886
Prepaid expenses and other assets				7,978
Total assets acquired		$ 693,900		688,674
Accounts payable, accrued expenses and other current liabilities				4,671
Asset retirement obligations				35,740
Operating lease liabilities				20,644
Other liabilities				7,007
Total liabilities assumed				68,062
Non-controlling interests				3,025
Purchase price, net of cash and restricted cash acquired				617,587
Deposit on acquisitions				114,195	$ 114,200
Total cash paid for the WGL Acquisition, net of cash acquired				731,782
Adjustments
Right-of-use assets				23,300
Cash and cash equivalents acquired				$ 3,400
Saeta Yield
As Reported
Renewable energy facilities in service	$ 1,987,282					1,993,520
Intangible assets	1,002,314					1,034,176
Accounts receivable	91,343					91,343
Goodwill	155,389					123,106
Other assets	46,247					43,402
Total assets acquired	3,282,575					3,285,547
Accounts payable, accrued expenses and other current liabilities	91,271					93,032
Asset retirement obligations	67,612					67,706
Other liabilities	23,002					23,002
Long-term debt, including current portion	1,922,970					1,906,831	$ 1,910,000
Deferred income taxes	154,117					171,373
Derivative liabilities	137,002					137,002
Total liabilities assumed	2,395,974					2,398,946
Non-controlling interests	55,117					55,117
Purchase price, net of cash acquired	831,484					$ 831,484
Adjustments
Renewable energy facilities in service	(6,238)
Intangible Assets	(31,862)
Goodwill	32,283
Other assets	2,845
Total assets acquired	(2,972)
Accounts payable, accrued expenses and other current liabilities	(1,761)
Long-term debt, including current portion	16,139
Deferred income taxes	(17,256)
Asset retirement obligations	(94)
Total liabilities assumed	(2,972)
Cash and cash equivalents acquired	187,200
Restricted cash acquired	95,100
Regulated Solar and Wind | Saeta Yield
As Reported
Goodwill	117,400
Wind | Saeta Yield
As Reported
Goodwill	$ 38,000

Acquisitions - Intangible Asset

Acquisitions - Intangible Assets at Acquisition Date (Details) - USD ($) $ in Thousands	Jun. 12, 2018	Sep. 30, 2019
Favorable rate revenue contracts | WGL Acquisition
Business Acquisition [Line Items]
Fair Value		$ 23,575
Weighted Average Amortization Period		16 years
In-place value of market rate revenue contracts | WGL Acquisition
Business Acquisition [Line Items]
Fair Value		$ 105,150
Weighted Average Amortization Period		15 years
Intangible assets - concession and licensing contracts | Saeta Yield
Business Acquisition [Line Items]
Fair Value	$ 1,034,176
Weighted Average Amortization Period	15 years
Unfavorable rate revenue contracts | WGL Acquisition
Business Acquisition [Line Items]
Fair Value		$ 7,007
Weighted Average Amortization Period		2 years

Acquisitions - Unaudited Pro Fo

Acquisitions - Unaudited Pro Forma Supplementary Data (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
WGL Acquisition
Business Acquisition [Line Items]
Total operating revenues, net	$ 790,403	$ 559,523
Net loss	$ (71,099)	31,985
Saeta Yield
Business Acquisition [Line Items]
Total operating revenues, net		740,066
Net loss		$ (108,314)

Acquisitions - Acquisition Cost

Acquisitions - Acquisition Cost (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition [Line Items]
Acquisition costs incurred	$ 1,000,000	$ 1,700,000	$ 1,400,000	$ 7,600,000
Acquisition costs related to affiliates	$ 0	$ 300,000	$ 0	$ 7,000,000

Cash and Cash Equivalents - Nar

Cash and Cash Equivalents - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Cash and Cash Equivalents [Line Items]
Non-current restricted cash reclassified	$ 11.2	$ 11.2
Cash and cash equivalents reclassified	2.2	1.4
Project Level Subsidiaries
Cash and Cash Equivalents [Line Items]
Cash	$ 188.4	$ 177.6

Cash and Cash Equivalents - Sch

Cash and Cash Equivalents - Schedule of Cash and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 239,297	$ 248,524
Restricted cash - current	31,140	27,784
Restricted cash - non-current	73,794	116,501
Cash, cash equivalents and restricted cash shown in the unaudited condensed consolidated statement of cash flows	$ 344,231	$ 392,809	$ 509,995	$ 224,787

Renewable Energy Facilities - R

Renewable Energy Facilities - Renewable Energy Facilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total renewable energy facilities, net	$ 6,967,149		$ 6,470,026
Right-of-use assets	269,309
Renewable energy facilities in service, net
Property, Plant and Equipment [Line Items]
Renewable energy facilities, net	8,037,096		7,298,371
Less: accumulated depreciation	(1,080,363)		(833,844)
Total renewable energy facilities, net	6,956,733		6,464,527
Construction in progress - renewable energy facilities
Property, Plant and Equipment [Line Items]
Renewable energy facilities, net	$ 10,416		$ 5,499
Accounting Standards Update 2016-02
Property, Plant and Equipment [Line Items]
Right-of-use assets		$ 252,700

Renewable Energy Facilities - N

Renewable Energy Facilities - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 84,100,000	$ 79,200,000	$ 240,000,000	$ 194,200,000
Impairment charge	$ 0	$ 0	$ 0	15,240,000
REC Sales Agreement
Property, Plant and Equipment [Line Items]
Impairment charge				$ 15,200,000

Leases - Narrative (Details)

Leases - Narrative (Details)	9 Months Ended
	Sep. 30, 2019
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	5 years
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	41 years

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Fixed operating lease cost	$ 4,740	$ 15,936
Variable operating lease cost	834	3,239
Total operating lease cost	$ 5,574	$ 19,175

Leases - Cash Flow Information

Leases - Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 5,472	$ 11,487

Leases - Balance Sheet Informat

Leases - Balance Sheet Information (Details) $ in Thousands	Sep. 30, 2019USD ($)
Operating leases:
Right-of-use assets	$ 269,309
Accounts payable, accrued expenses and other current liabilities	14,980
Operating lease obligations, less current portion	255,507
Total operating lease liabilities	$ 270,487
Weighted Average Remaining Lease Term:
Operating leases	18 years
Weighted Average Discount Rate:
Operating leases	4.50%

Leases - Maturity of Lease Liab

Leases - Maturity of Lease Liabilities (Details) $ in Thousands	Sep. 30, 2019USD ($)
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2019	$ 10,417
2020	21,280
2021	21,566
2022	21,434
2023	22,073
Thereafter	324,230
Total lease payments	421,000
Less: Imputed interest	(150,513)
Total	$ 270,487

Intangible Assets, Net and Go_3

Intangible Assets, Net and Goodwill - Accumulated amortization and net book value of intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	$ 52,777		$ 52,777		$ 64,508
Accumulated Amortization	(35,074)		(35,074)		(45,625)
Net Book Value	17,703		17,703		18,883
Total intangible assets, net
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	2,346,105		2,346,105		2,302,956
Accumulated Amortization	(388,959)		(388,959)		(306,552)
Net Book Value	1,957,146		1,957,146		1,996,404
Total intangible assets, net | Operating revenues, net
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Net amortization	9,800	$ 9,900	28,600	$ 29,500
Total intangible assets, net | Depreciation, Accretion, and Amortization
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Net amortization	6,800	4,700	19,700	21,600
Concession and licensing contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	948,740		948,740		1,015,824
Accumulated Amortization	(83,182)		(83,182)		(36,374)
Net Book Value	865,558		865,558		$ 979,450
Concession and licensing contracts | Operating revenues, net
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Net amortization	16,900	$ 13,800	$ 50,100	$ 16,700
Concession and licensing contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			14 years		15 years
Favorable rate revenue contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	746,126		$ 746,126		$ 738,488
Accumulated Amortization	(184,983)		(184,983)		(166,507)
Net Book Value	561,143		$ 561,143		$ 571,981
Favorable rate revenue contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			13 years		14 years
In-place value of market rate revenue contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	651,239		$ 651,239		$ 532,844
Accumulated Amortization	(120,794)		(120,794)		(100,543)
Net Book Value	530,445		$ 530,445		$ 432,301
In-place value of market rate revenue contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			17 years		18 years
Favorable rate land leases
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount					$ 15,800
Accumulated Amortization					(3,128)
Net Book Value					$ 12,672
Favorable rate land leases | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period					16 years
Unfavorable rate revenue contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	47,777		$ 47,777		$ 58,508
Accumulated Amortization	(30,304)		(30,304)		(41,605)
Net Book Value	17,473		$ 17,473		$ 16,903
Unfavorable rate revenue contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			6 years		6 years
Unfavorable rate operations and maintenance contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	5,000		$ 5,000		$ 5,000
Accumulated Amortization	(4,770)		(4,770)		(3,802)
Net Book Value	$ 230		$ 230		$ 1,198
Unfavorable rate operations and maintenance contracts | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period			3 months		1 year
Unfavorable rate land lease
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount					$ 1,000
Accumulated Amortization					(218)
Net Book Value					$ 782
Unfavorable rate land lease | Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period					14 years

Intangible Assets, Net and Go_4

Intangible Assets, Net and Goodwill - Goodwill (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Goodwill [Roll Forward]
Beginning balance	$ 120,553	$ 0	$ 145,616	$ 120,553
Goodwill resulting from business combinations	0	115,381
Goodwill	32,283	7,726
Foreign exchange differences	(7,220)	(2,554)
Ending balance	$ 120,553	$ 0

Variable Interest Entities (Det

Variable Interest Entities (Details) - Consolidated Variable Interest Entity, Primary Beneficiary - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Current assets	$ 134,551	$ 134,057
Non-current assets	4,032,239	3,909,549
Total assets	4,166,790	4,043,606
Current liabilities	319,738	120,790
Non-current liabilities	949,812	1,014,789
Total liabilities	$ 1,269,550	$ 1,135,579

Long-term Debt - Debt (Details)

Long-term Debt - Debt (Details) - USD ($)	Oct. 16, 2019	Oct. 08, 2019	Sep. 30, 2019	Sep. 25, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total principal due for long-term debt and financing obligations			$ 6,294,721,000		$ 5,796,936,000
Unamortized premiums and discounts, net			3,758,000		(15,913,000)
Deferred financing costs, net			(38,036,000)		(19,178,000)
Less: current portion of long-term debt and financing lease obligations			(635,929,000)		(464,332,000)
Long-term debt and financing obligations, less current portion			$ 5,624,514,000		5,297,513,000
Variable/blended/imputed interest rate			4.53%
Secured Debt
Debt Instrument [Line Items]
Total principal due for long-term debt and financing obligations			$ 3,557,646,000		3,496,370,000
Variable/blended/imputed interest rate			4.55%
Percentage of debt bearing fixed interest rate			36.00%
Variable interest rate			64.00%
Secured Debt | Senior Notes due 2023
Debt Instrument [Line Items]
Total principal due for long-term debt and financing obligations			$ 500,000,000		500,000,000
Fixed interest rate			4.25%
Secured Debt | Senior Notes due 2025
Debt Instrument [Line Items]
Total principal due for long-term debt and financing obligations			$ 300,000,000		300,000,000
Fixed interest rate			6.63%
Secured Debt | Senior Notes due 2028
Debt Instrument [Line Items]
Total principal due for long-term debt and financing obligations			$ 700,000,000		700,000,000
Fixed interest rate			5.00%
Secured Debt | Term Loan
Debt Instrument [Line Items]
Total principal due for long-term debt and financing obligations			$ 343,875,000		346,500,000
Variable/blended/imputed interest rate			4.04%
Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Total principal due for long-term debt and financing obligations			$ 356,000,000		377,000,000
Variable/blended/imputed interest rate			4.27%
Bridge Facility
Debt Instrument [Line Items]
Total principal due for long-term debt and financing obligations			$ 475,000,000		0
Variable/blended/imputed interest rate			3.09%
Face amount of debt instrument				$ 475,000,000
Financing obligations
Debt Instrument [Line Items]
Total principal due for long-term debt and financing obligations			$ 62,200,000		$ 77,066,000
Variable/blended/imputed interest rate			5.85%
Subsequent Event | Secured Debt | 4.75% Senior Notes Due in 2030
Debt Instrument [Line Items]
Fixed interest rate	4.75%
Face amount of debt instrument	$ 700,000,000
Issuance price percentage of face amount	100.00%
Subsequent Event | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Increase in borrowing capacity		$ 200,000,000

Long-term Debt - Narrative (Det

Long-term Debt - Narrative (Details)	Sep. 25, 2019USD ($)MW	Aug. 30, 2019USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)	Aug. 30, 2018MW
Debt Instrument [Line Items]
Defaulted debt, reclassified to current			$ 387,800,000	$ 186,300,000
Bridge Facility
Debt Instrument [Line Items]
Face amount of debt instrument	$ 475,000,000
Capacity of power plant (MW) | MW	320
Debt extension term	1 year
3.2% Senior Notes Due July 2032 | Secured Debt
Debt Instrument [Line Items]
Face amount of debt instrument		$ 131,000,000
Fixed interest rate		0.032%
Capacity of power plant (MW) | MW					111
Debt term		13 years

Long-term Debt - Aggregate Cont

Long-term Debt - Aggregate Contractual Payments of Long-term Debt (Details) - USD ($)	Sep. 30, 2019	Sep. 25, 2019	Dec. 31, 2018
Maturities of long-term debt1
Remainder of 2019	$ 96,852,000
2020	732,185,000
2021	269,528,000
2022	770,751,000
2023	1,220,271,000
Thereafter	3,205,134,000
Total	6,294,721,000
Defaulted debt, reclassified to current	$ 387,800,000		$ 186,300,000
Bridge Facility
Maturities of long-term debt1
Face amount of debt instrument		$ 475,000,000

Income Taxes - Components of In

Income Taxes - Components of Income Tax Provision (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Loss before income tax expense	$ (60,801)	$ (13,038)	$ (112,167)	$ (113,559)
Income tax expense	$ 1,512	$ 6,013	$ 3,030	$ 9,417
Effective tax rate	(2.50%)	(46.10%)	(2.70%)	(8.30%)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Statutory tax rate	21.00%	21.00%	21.00%	21.00%

Derivatives - Schedule of Fair

Derivatives - Schedule of Fair Values of Derivative Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	$ 126,891	$ 106,556
Counterparty Netting	(887)	(1,201)
Net derivative assets	126,004	105,355
Gross amounts of derivative liabilities	180,771	130,608
Counterparty Netting	(887)	(1,201)
Net derivative liabilities	179,884	129,407
Derivative assets, current
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	29,016	15,228
Counterparty Netting	(108)	(857)
Net derivative assets	28,908	14,371
Derivative assets
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	97,875	91,328
Counterparty Netting	(779)	(344)
Net derivative assets	97,096	90,984
Derivative liabilities, current portion
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	38,837	36,416
Counterparty Netting	(108)	(857)
Net derivative liabilities	38,729	35,559
Derivative liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	141,934	94,192
Counterparty Netting	(779)	(344)
Net derivative liabilities	141,155	93,848
Interest Rate Swaps | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	0	7,296
Gross amounts of derivative liabilities	41,302	3,799
Interest Rate Swaps | Derivatives Designated as Hedging Instruments | Derivative assets, current
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	0	1,478
Interest Rate Swaps | Derivatives Designated as Hedging Instruments | Derivative assets
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	0	5,818
Interest Rate Swaps | Derivatives Designated as Hedging Instruments | Derivative liabilities, current portion
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	5,717	465
Interest Rate Swaps | Derivatives Designated as Hedging Instruments | Derivative liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	35,585	3,334
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	0	0
Gross amounts of derivative liabilities	138,582	122,301
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments | Derivative assets, current
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	0	0
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments | Derivative assets
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	0	0
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments | Derivative liabilities, current portion
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	33,012	34,267
Interest Rate Swaps | Derivatives Not Designated as Hedging Instruments | Derivative liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	105,570	88,034
Foreign Currency Contracts | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	11,048	2,665
Gross amounts of derivative liabilities	112	1,437
Foreign Currency Contracts | Derivatives Designated as Hedging Instruments | Derivative assets, current
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	1,217	605
Foreign Currency Contracts | Derivatives Designated as Hedging Instruments | Derivative assets
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	9,831	2,060
Foreign Currency Contracts | Derivatives Designated as Hedging Instruments | Derivative liabilities, current portion
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	108	0
Foreign Currency Contracts | Derivatives Designated as Hedging Instruments | Derivative liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	4	1,437
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	23,711	3,991
Gross amounts of derivative liabilities	775	3,071
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments | Derivative assets, current
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	19,365	3,344
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments | Derivative assets
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	4,346	647
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments | Derivative liabilities, current portion
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	0	1,684
Foreign Currency Contracts | Derivatives Not Designated as Hedging Instruments | Derivative liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	775	1,387
Commodity Contracts | Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	42,044	42,684
Gross amounts of derivative liabilities	0	0
Commodity Contracts | Derivatives Designated as Hedging Instruments | Derivative assets, current
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	365	18
Commodity Contracts | Derivatives Designated as Hedging Instruments | Derivative assets
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	41,679	42,666
Commodity Contracts | Derivatives Designated as Hedging Instruments | Derivative liabilities, current portion
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	0	0
Commodity Contracts | Derivatives Designated as Hedging Instruments | Derivative liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	0	0
Commodity Contracts | Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	50,088	49,920
Gross amounts of derivative liabilities	0	0
Commodity Contracts | Derivatives Not Designated as Hedging Instruments | Derivative assets, current
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	8,069	9,783
Commodity Contracts | Derivatives Not Designated as Hedging Instruments | Derivative assets
Derivatives, Fair Value [Line Items]
Gross amounts of derivative assets	42,019	40,137
Commodity Contracts | Derivatives Not Designated as Hedging Instruments | Derivative liabilities, current portion
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	0	0
Commodity Contracts | Derivatives Not Designated as Hedging Instruments | Derivative liabilities
Derivatives, Fair Value [Line Items]
Gross amounts of derivative liabilities	$ 0	$ 0

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) € in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2019USD ($)derivative_instrument	Dec. 31, 2018USD ($)	Sep. 30, 2019CAD ($)derivative_instrument	Sep. 30, 2019EUR (€)derivative_instrument	Dec. 31, 2018CAD ($)	Dec. 31, 2018EUR (€)
Derivative Instruments, Gain (Loss) [Line Items]
Collateral already posted	$ 0	$ 0
Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Maximum term of outstanding interest rate swaps	8 years
Number of derivative instruments | derivative_instrument	2		2	2
Gain expected to be reclassified into earnings, commodity contracts	$ 2,400,000
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, interest rate swap	$ 5,200,000
Maximum term of outstanding interest rate swaps	20 years
Derivatives designated as hedges | Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount	$ 867,184,000	$ 357,797,000	$ 139,075		$ 147,522
Derivatives designated as hedges | Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount			$ 94,100	€ 200,000	$ 81,600	€ 320,000
Derivatives designated as hedges | Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Number of derivative instruments | derivative_instrument	1		1	1
Net Investment Hedging | Derivatives designated as hedges | Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount			$ 94,100	€ 200,000
Minimum | Net Investment Hedging | Derivatives designated as hedges | Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Maturity of derivative instruments	3 months	3 months
Maximum | Net Investment Hedging | Derivatives designated as hedges | Foreign currency contracts
Derivative Instruments, Gain (Loss) [Line Items]
Maturity of derivative instruments	18 months	2 years

Derivatives - Schedule of Notio

Derivatives - Schedule of Notional Amounts for Derivative Instruments (Details) € in Thousands, MWh in Thousands, $ in Thousands, $ in Thousands	Mar. 31, 2019MWh	Dec. 31, 2018USD ($)MWh	Sep. 30, 2019USD ($)	Sep. 30, 2019CAD ($)	Sep. 30, 2019EUR (€)	Dec. 31, 2018CAD ($)	Dec. 31, 2018EUR (€)
Interest rate swaps | Derivatives designated as hedging instruments
Derivative [Line Items]
Notional amount		$ 357,797	$ 867,184	$ 139,075		$ 147,522
Interest rate swaps | Derivatives not designated as hedging instruments
Derivative [Line Items]
Notional amount		12,326	11,616		€ 991,942		€ 1,044,253
Foreign Exchange Option | Derivatives not designated as hedging instruments
Derivative [Line Items]
Notional amount | €					625,200		0
Foreign currency contracts | Derivatives designated as hedging instruments
Derivative [Line Items]
Notional amount				$ 94,100	200,000	$ 81,600	320,000
Foreign currency contracts | Derivatives not designated as hedging instruments
Derivative [Line Items]
Notional amount		$ 0	$ 7,800		€ 165,000		€ 640,200
Commodity contracts | Derivatives designated as hedging instruments
Derivative [Line Items]
Notional amount (in MWhs)	5,528	6,030
Commodity contracts | Derivatives not designated as hedging instruments
Derivative [Line Items]
Notional amount (in MWhs)	7,895	8,707

Derivatives - Gains and Losses

Derivatives - Gains and Losses on Derivatives Not Designated As Hedges (Details) - Derivatives not designated as hedging instruments - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Interest expense, net | Interest rate swaps
Derivative [Line Items]
Loss (gain) on derivatives	$ 20,911	$ 4,737	$ 50,189	$ (3,252)
Loss (gain) on foreign currency exchange, net | Foreign currency contracts
Derivative [Line Items]
Loss (gain) on derivatives	(19,667)	(4,348)	(39,596)	(16,914)
Operating revenues, net | Commodity contracts
Derivative [Line Items]
Loss (gain) on derivatives	$ 307	$ (3,880)	$ (13,311)	$ (21,374)

Derivatives - Gains (Losses) Re

Derivatives - Gains (Losses) Recognized Related to Interest Rate Swaps and Commodity Contracts Designated as Cash Flow Hedges (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Derivative [Line Items]
(Loss) Gain Included in the Assessment of Effectiveness Recognized in OCI, net of taxes	$ (16,653,000)	$ 10,621,000	$ (43,941,000)	$ 12,528,000
Loss (Gain) Included in the Assessment of Effectiveness Reclassified from AOCI into Income	3,389,000	(5,832,000)	(2,439,000)	(6,755,000)
Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, tax expense (benefit)		0	0	0
(Gain) Loss Included in the Assessment of Effectiveness Reclassified from AOCI into Income, tax expense (benefit)	0	0
Interest rate swaps
Derivative [Line Items]
Gain (Loss) Included in the Assessment of Effectiveness Recognized in OCI, tax expense (benefit)	(2,506,000)		(2,506,000)
(Gain) Loss Included in the Assessment of Effectiveness Reclassified from AOCI into Income, tax expense (benefit)			0	0
Derivatives designated as hedges
Derivative [Line Items]
(Loss) Gain Included in the Assessment of Effectiveness Recognized in OCI, net of taxes	(9,567,000)	12,301,000	(23,750,000)	15,342,000
Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach	0	0	0	735,000
Loss (Gain) Included in the Assessment of Effectiveness Reclassified from AOCI into Income	4,922,000	(4,756,000)	3,249,000	(5,825,000)
(Gain) Excluded from the Assessment of Effectiveness that is Amortized through Earnings	0	(251,000)	0	(930,000)
Derivatives designated as hedges | Interest rate swaps
Derivative [Line Items]
(Loss) Gain Included in the Assessment of Effectiveness Recognized in OCI, net of taxes	(14,722,000)	4,107,000	(41,336,000)	14,627,000
Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach	0	0	0	0
Derivatives designated as hedges | Foreign currency contracts
Derivative [Line Items]
(Loss) Gain Included in the Assessment of Effectiveness Recognized in OCI, net of taxes	11,915,000	3,549,000	20,191,000	3,549,000
Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach	0	0	0	0
Derivatives designated as hedges | Commodity contracts
Derivative [Line Items]
(Loss) Gain Included in the Assessment of Effectiveness Recognized in OCI, net of taxes	(6,760,000)	4,645,000	(2,605,000)	(2,834,000)
Gain (Loss) Excluded from the Assessment of Effectiveness Recognized in OCI Using an Amortization Approach	0	0	0	735,000
Derivatives designated as hedges | Interest expense, net | Interest rate swaps
Derivative [Line Items]
Loss (Gain) Included in the Assessment of Effectiveness Reclassified from AOCI into Income	128,000	263,000	(867,000)	1,236,000
(Gain) Excluded from the Assessment of Effectiveness that is Amortized through Earnings	0	0	0	0
Derivatives designated as hedges | (Gain) on foreign currency exchange, net | Foreign currency contracts
Derivative [Line Items]
Loss (Gain) Included in the Assessment of Effectiveness Reclassified from AOCI into Income	0	0	0	0
(Gain) Excluded from the Assessment of Effectiveness that is Amortized through Earnings	0	0	0	0
Derivatives designated as hedges | Operating revenues, net | Commodity contracts
Derivative [Line Items]
Loss (Gain) Included in the Assessment of Effectiveness Reclassified from AOCI into Income	4,794,000	(5,019,000)	4,116,000	(7,061,000)
(Gain) Excluded from the Assessment of Effectiveness that is Amortized through Earnings	$ 0	$ (251,000)	$ 0	$ (930,000)

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Financial Instruments Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 126,004	$ 105,355
Liabilities	179,884	129,407
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	126,004	105,355
Liabilities	179,884	129,407
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	0	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	41,425	25,567
Liabilities	179,884	129,407
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	84,579	79,788
Liabilities	0	0
Interest rate swaps | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	7,296
Liabilities	179,884	126,100
Interest rate swaps | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	0	0
Interest rate swaps | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	7,296
Liabilities	179,884	126,100
Interest rate swaps | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	0	0
Commodity contracts | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	92,132	92,604
Commodity contracts | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Commodity contracts | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	7,553	12,816
Commodity contracts | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	84,579	79,788
Foreign currency contracts | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	33,872	5,455
Liabilities	0	3,307
Foreign currency contracts | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	0	0
Foreign currency contracts | Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	33,872	5,455
Liabilities	0	3,307
Foreign currency contracts | Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	0	0
Liabilities	$ 0	$ 0

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Changes in Fair Value of Derivative Instruments Classified as Level 3 (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	$ 86,079	$ 81,859	$ 79,652	$ 80,268
Realized and unrealized gains (losses):
Included in other comprehensive (loss) income	(6,760)	418	(2,605)	(10,090)
Included in operating revenues, net	(2,295)	1,324	3,793	16,873
Settlements	7,555	583	3,739	(2,867)
Ending balance	$ 84,579	$ 84,184	$ 84,579	$ 84,184

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Significant Unobservable Inputs Used in Valuation of Commodity Contracts (Details) $ in Thousands	Sep. 30, 2019USD ($)$ / MWh	Dec. 31, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 126,004	$ 105,355
Liabilities	179,884	$ 129,407
Commodity contracts - power | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	84,579
Liabilities	$ 0
Minimum | Forward price | Commodity contracts - power | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Inputs | $ / MWh	7.15
Minimum | Forward price (per MWh) | Commodity contracts - power | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Inputs	0.145
Maximum | Forward price | Commodity contracts - power | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Unobservable Inputs | $ / MWh	177.20

Fair Value of Financial Instr_6

Fair Value of Financial Instruments - Carrying Amount and Estimated Fair Value of Long-term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Carrying Amount	$ 6,260,443	$ 5,761,845
Fair Value	$ 6,521,099	$ 5,789,702

Fair Value of Financial Instr_7

Fair Value of Financial Instruments - Narrative (Details)	Sep. 30, 2019	Dec. 31, 2018
Senior Notes due 2023
Debt Instrument [Line Items]
Fair value as a percentage of face value	102.40%	93.50%
Senior Notes due 2025
Debt Instrument [Line Items]
Fair value as a percentage of face value	104.80%	89.80%
Senior Notes due 2028
Debt Instrument [Line Items]
Fair value as a percentage of face value	106.10%	102.50%

Stockholders' Equity - Common S

Stockholders' Equity - Common Stock Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 03, 2018	Jun. 12, 2018	Jun. 11, 2018	Sep. 30, 2019	Sep. 30, 2018
Common Stock Activity [Roll Forward]
Balance at beginning of period (in shares)				209,142,000	148,086,000
Issuance of Common Stock to affiliates (in shares)	80,084		60,975,609	0	61,056,000
Net shares issued under equity incentive plan (in shares)				13,000	0
Balance at end of period (in shares)				209,155,000	209,142,000
Price of shares issued (in dollars per share)			$ 10.66
Proceeds from issuance of consideration		$ 650,000	$ 650,000	$ 0	$ 650,000

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jul. 25, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Preferred shares authorized (in shares)	100,000,000		100,000,000
Preferred stock, par value (dollars per share)	$ 0.01		$ 0.01
Common stock, shares authorized (in shares)	1,200,000,000		1,200,000,000			1,200,000,000
Common stock, par value (in dollars per share)	$ 0.01		$ 0.01			$ 0.01
Contractual term			10 years
Number of shares available for issuance (in shares)	3,725,555		3,725,555			3,822,821
Share repurchase program, authorized amount, percentage of common stock outstanding					5.00%
Shares repurchased (in shares)			0
Restricted Stock Units (RSUs)
Class of Stock [Line Items]
Net shares issued under equity incentive plan			156,550
Grant-date fair value			$ 1.9
Vesting period			3 years
Stock-based compensation expense	$ 0.3	$ 0.1	$ 0.5	$ 0.2
Cost not yet recognized	$ 1.8		$ 1.8
Cost not yet recognized, period for recognition			1 year 7 months 6 days

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Restricted Stock Units (Details) - Restricted Stock Units (RSUs)	9 Months Ended
	Sep. 30, 2019USD ($)$ / sharesshares
Number of RSUs Outstanding
Beginning balance (in shares) | shares	103,300
Granted (in shares) | shares	156,550
Vested (in shares) | shares	(20,878)
Forfeited (in shares) | shares	(38,406)
Ending balance (in shares) | shares	200,566
Weighted- Average Exercise Price
Beginning balance (dollars per share) | $ / shares	$ 11.15
Granted (in shares) | $ / shares	12.17
Vested (in shares) | $ / shares	11.15
Forfeited (in shares) | $ / shares	11.65
Ending balance (dollars per share) | $ / shares	$ 11.85
Aggregate Intrinsic Value (in thousands) | $	$ 3,861,200
Weighted Average Remaining Contractual Life (in years)	1 year 7 months 6 days

Stockholders' Equity - Cash Dis

Stockholders' Equity - Cash Distributions (Details) - $ / shares	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Equity [Abstract]
Distributions per Share (in dollars per share)	$ 0.2014	$ 0.2014	$ 0.2014	$ 0.19	$ 0.19	$ 0.19	$ 0.6042	$ 0.57

(Loss) Earnings Per Share (Deta

(Loss) Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net (loss) income attributable to Class A common stockholders	$ (54,837)	$ (33,590)	$ (67,059)	$ 27,869
Weighted average basic Class A shares outstanding (in shares)	209,155,000	209,142,000	209,149,000	173,173,000
Weighted average diluted Class A shares outstanding (in shares)	209,155,000	209,142,000	209,149,000	173,186,000
Basic and diluted earnings (loss) per share (in dollars per share)	$ (0.26)	$ (0.16)	$ (0.32)	$ 0.16
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Shares considered to be dilutive (in shares)		0		66,000
Restricted Stock Units (RSUs)
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Shares excluded from calculation (in shares)		103,000	36,000	13,000

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	Nov. 01, 2019	Aug. 10, 2018MW	May 27, 2016USD ($)employee	Dec. 31, 2019USD ($)MW	Jun. 30, 2019claim	Jan. 31, 2019USD ($)	Sep. 30, 2019USD ($)businessplaintiffMW	Sep. 30, 2018USD ($)businessMW	Dec. 31, 2018USD ($)
Loss Contingencies [Line Items]
Outstanding letters of credit							$ 257,400		$ 197,700
Payments to acquired assets							18,255	$ 4,105
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							$ 112,600		$ 99,500
General Electric | Framework Agreement
Loss Contingencies [Line Items]
Long-term service agreement term		11 years
Capacity of power plant (MW) | MW		1,600
Solar Distributed Generation Portfolio
Loss Contingencies [Line Items]
Capacity of power plant (MW) | MW							10.6	6.1
Number of assets acquired | business							3	6
Payments to acquired assets							$ 18,300	$ 4,100
Forecast | Solar Distributed Generation Portfolio
Loss Contingencies [Line Items]
Capacity of power plant (MW) | MW				4.5
Payments to acquired assets				$ 6,000
Subsequent Event | SMA Solar Technology | LTSA
Loss Contingencies [Line Items]
Long-term service agreement term	10 years
Judicial Ruling | Chile Project Arbitration
Loss Contingencies [Line Items]
Number of claims | claim					2
Pending Litigation | Court Of Federal Claims | Project Level Subsidiaries
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff							2
Damages awarded						$ 10,000

Related Parties - Additional In

Related Parties - Additional Information (Narrative) (Details) - shares	Oct. 08, 2019	Sep. 30, 2019	Dec. 31, 2018
Class A common stock | Orion Holdings
Related Party Transaction [Line Items]
Ownership percentage		65.00%	65.00%
Subsequent Event | Affiliates of Brookfield
Related Party Transaction [Line Items]
Percentage of ownership	61.00%
Private Placement | Subsequent Event
Related Party Transaction [Line Items]
Public offering common stock (in shares)	2,981,514

Related Parties - Brookfield Ma

Related Parties - Brookfield Master Services Agreement (Narrative) (Details) - Affiliated Entity - Brookfield MSA - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Related Party Transaction [Line Items]
Base management fee	$ 2,500,000		$ 2,500,000
Management fee as related to market capitalization			0.3125%
Base management fee maximum, year two	3,000,000		$ 3,000,000
Base management fee, thereafter	3,750,000		$ 3,750,000
Management fee, share price multiplier (in dollars per share)			$ 9.52
Charges within general and administrative expenses - affiliate	7,500,000	$ 3,600,000	$ 18,300,000	$ 10,500,000
Balance payable	$ 7,500,000		$ 7,500,000		$ 4,200,000

Related Parties - New Terra LLC

Related Parties - New Terra LLC Agreement (Narrative) (Details) - Affiliated Entity - IDRs	9 Months Ended
	Sep. 30, 2019USD ($)$ / shares
Related Party Transaction [Line Items]
First distribution threshold (in dollars per share)	$ 0.93
Second distribution threshold (in dollars per share)	$ 1.05
Payments of IDRs | $	$ 0

Related Parties - Sponsor Line

Related Parties - Sponsor Line Agreement (Details) - Revolving Credit Facility - USD ($)	Oct. 16, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Line of Credit
Related Party Transaction [Line Items]
Maximum borrowing capacity		$ 800,000,000		$ 800,000,000
Sponsor Line
Related Party Transaction [Line Items]
Interest expense		$ 1,000,000	$ 1,900,000	$ 3,100,000	$ 4,100,000
Sponsor Line | Line of Credit
Related Party Transaction [Line Items]
Percentage of capital stock	100.00%
Sponsor Line | Grand Duchy of Luxembourg | Line of Credit
Related Party Transaction [Line Items]
Maximum borrowing capacity	$ 500,000,000
Debt term	3 years
LIBOR | Sponsor Line | Line of Credit
Related Party Transaction [Line Items]
Basis spread on variable rate	3.00%
LIBOR | Revolver | Line of Credit
Related Party Transaction [Line Items]
Standby fee percentage	0.50%

Related Parties - Lease (Narrat

Related Parties - Lease (Narrative) (Details) - Brookfield and Affiliates - Relocation Of Corporate Headquarters - Affiliated Entity - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	May 31, 2018
Related Party Transaction [Line Items]
Term of lease					10 years
Charges within general and administrative expenses - affiliate	$ 0.3	$ 0.2	$ 0.7	$ 0.1

Related Parties - Due from Affi

Related Parties - Due from Affiliate (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Due from affiliate	$ 265	$ 196
TerraForm Global, Inc. | Affiliated Entity
Related Party Transaction [Line Items]
Due from affiliate	$ 200

Related Parties - Due to Affili

Related Parties - Due to Affiliates (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Related Party Transaction [Line Items]
Due to affiliates	$ 8,878		$ 8,878		$ 6,991
Payments to affiliates			(1,818)	$ (4,158)
Acquisition-related costs payable
Related Party Transaction [Line Items]
Due to affiliates	1,400		1,400
Affiliates of Brookfield | Base management fee
Related Party Transaction [Line Items]
Due to affiliates	7,500		7,500		4,200
Payments to affiliates	5,900	$ 3,600	15,000	10,300
Affiliates of Brookfield | Leasehold improvements
Related Party Transaction [Line Items]
Due to affiliates					$ 2,800
Affiliates of Brookfield | Accrued standby fee interest
Related Party Transaction [Line Items]
Payments to affiliates	$ 2,100	$ 2,400	$ 5,300	$ 4,200

Segment Reporting (Details)

Segment Reporting (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)segment	Sep. 30, 2018USD ($)	Sep. 26, 2019USD ($)	Dec. 31, 2018USD ($)
Segment Reporting [Abstract]
Number of reportable segments | segment			3
Segment Reporting Information, Profit (Loss)
Operating revenues, net	$ 253,808,000	$ 246,042,000	$ 734,506,000	$ 553,477,000
Depreciation, accretion and amortization expense	114,282,000	103,593,000	321,605,000	239,177,000
Impairment of renewable energy facilities	0	0	0	15,240,000
Other operating costs and expenses	99,161,000	85,783,000	288,504,000	237,144,000
Operating income (loss)	40,365,000	56,666,000	124,397,000	61,916,000
Interest expense, net	89,393,000	72,416,000	246,721,000	176,862,000
Other non-operating expenses (income), net	11,773,000	(2,712,000)	(10,157,000)	(1,387,000)
Income tax expense	1,512,000	6,013,000	3,030,000	9,417,000
Net income (loss)	(62,313,000)	(19,051,000)	(115,197,000)	(122,976,000)
Balance Sheet
Total assets	9,929,191,000		9,929,191,000			$ 9,330,354,000
Solar1
Segment Reporting Information, Profit (Loss)
Operating revenues, net	101,654,000	94,883,000	241,593,000	237,927,000
Wind
Segment Reporting Information, Profit (Loss)
Operating revenues, net	54,507,000	56,963,000	223,982,000	200,068,000
Segments | Solar1
Segment Reporting Information, Profit (Loss)
Operating revenues, net	101,654,000	94,883,000	241,593,000	237,927,000
Depreciation, accretion and amortization expense	29,753,000	28,299,000	84,829,000	83,041,000
Impairment of renewable energy facilities			0	15,240,000
Other operating costs and expenses	9,912,000	11,109,000	41,274,000	39,792,000
Operating income (loss)	61,989,000	55,475,000	115,490,000	99,854,000
Interest expense, net	17,302,000	15,992,000	46,693,000	46,248,000
Other non-operating expenses (income), net	428,000	632,000	(6,391,000)	(1,926,000)
Income tax expense	3,653,000	749,000	1,532,000	749,000
Net income (loss)	40,606,000	38,102,000	73,656,000	54,783,000
Balance Sheet
Total assets	3,587,474,000		3,587,474,000			2,762,977,000
Segments | Wind
Segment Reporting Information, Profit (Loss)
Operating revenues, net	54,507,000	56,963,000	223,982,000	200,068,000
Depreciation, accretion and amortization expense	49,052,000	40,992,000	132,694,000	113,926,000
Impairment of renewable energy facilities			0	0
Other operating costs and expenses	38,120,000	31,302,000	113,585,000	89,834,000
Operating income (loss)	(32,665,000)	(15,331,000)	(22,297,000)	(3,692,000)
Interest expense, net	16,220,000	14,367,000	45,173,000	36,382,000
Other non-operating expenses (income), net	(132,000)	(347,000)	(550,000)	538,000
Income tax expense	401,000	927,000	830,000	1,291,000
Net income (loss)	(49,154,000)	(30,278,000)	(67,750,000)	(41,903,000)
Balance Sheet
Total assets	3,762,649,000		3,762,649,000			3,733,049,000
Segments | Regulated Solar and Wind
Segment Reporting Information, Profit (Loss)
Operating revenues, net	97,647,000	94,196,000	268,931,000	115,482,000
Depreciation, accretion and amortization expense	34,957,000	33,954,000	102,955,000	41,148,000
Impairment of renewable energy facilities			0	0
Other operating costs and expenses	28,085,000	24,971,000	66,791,000	30,012,000
Operating income (loss)	34,605,000	35,271,000	99,185,000	44,322,000
Interest expense, net	27,073,000	9,632,000	65,539,000	4,879,000
Other non-operating expenses (income), net	599,000	(727,000)	449,000	(617,000)
Income tax expense	(2,543,000)	2,268,000	553,000	4,442,000
Net income (loss)	9,476,000	24,098,000	32,644,000	35,618,000
Balance Sheet
Total assets	2,496,186,000		2,496,186,000			2,748,126,000
Corporate
Segment Reporting Information, Profit (Loss)
Operating revenues, net	0	0	0	0
Depreciation, accretion and amortization expense	520,000	348,000	1,127,000	1,062,000
Impairment of renewable energy facilities			0	0
Other operating costs and expenses	23,044,000	18,401,000	66,854,000	77,506,000
Operating income (loss)	(23,564,000)	(18,749,000)	(67,981,000)	(78,568,000)
Interest expense, net	28,798,000	32,425,000	89,316,000	89,353,000
Other non-operating expenses (income), net	10,878,000	(2,270,000)	(3,665,000)	618,000
Income tax expense	1,000	2,069,000	115,000	2,935,000
Net income (loss)	(63,241,000)	$ (50,973,000)	(153,747,000)	$ (171,474,000)
Balance Sheet
Total assets	82,882,000		82,882,000			$ 86,202,000
WGL Acquisition
Balance Sheet
Total assets acquired	$ 693,900,000		$ 693,900,000		$ 688,674,000

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Jan. 01, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ 2,568,167	$ 2,651,284	$ 2,734,922	$ 2,886,698	$ 2,296,257	$ 2,387,712	$ 2,734,922	$ 2,387,712
Cumulative-effect adjustment (net of tax expense of $1,579)2										$ 20,106
Other comprehensive (loss) income, net of tax	(6,330)	(16,995)	(7,249)	5,235	7,046	(14,737)	(30,574)	(2,456)
Accumulated other comprehensive (loss) income	8,744						8,744		$ 40,238
Ending balance	2,467,434	2,568,167	2,651,284	2,813,088	2,886,698	2,296,257	2,467,434	2,813,088
Accumulated Other Comprehensive Income Attributable to Parent
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	15,262	32,313	40,238	37,400	30,360	48,018	40,238	48,018
Cumulative-effect adjustment (net of tax expense of $1,579)2										(4,164)
Other comprehensive (loss) income, net of tax	(6,518)	(17,051)	(7,925)	7,036	7,040	(13,494)
Ending balance	8,744	$ 15,262	32,313	44,436	$ 37,400	30,360	8,744	44,436
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			(8,405)			(13,412)	(8,405)	(13,412)
Cumulative-effect adjustment (net of tax expense of $1,579)2										0
Ending balance	7,401			(21,641)			7,401	(21,641)
Hedging Activities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance			$ 48,643			$ 61,430	48,643	61,430
Cumulative-effect adjustment (net of tax expense of $1,579)2										$ (4,164)
Ending balance	1,343			66,077			1,343	66,077
Cumulative effect adjustment, tax									$ 1,579
Foreign Currency Translation Adjustments Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net unrealized (loss) gain arising during the period							15,806	(8,229)
Reclassification of net realized gain into earnings							0	0
Other comprehensive (loss) income, net of tax							15,806	(8,229)
Accumulated other comprehensive (loss) income	7,401			(21,641)			7,401	(21,641)
OCI before reclassifications, tax expense (benefit)							0	0
Reclassification from AOCI, tax expense (benefit)							0	0
Hedging Activities Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net unrealized (loss) gain arising during the period							(43,941)	12,528
Reclassification of net realized gain into earnings							(2,439)	(6,755)
Other comprehensive (loss) income, net of tax							(46,380)	5,773
Accumulated other comprehensive (loss) income	2,263			63,039			2,263	63,039
OCI before reclassifications, tax expense (benefit)							(2,506)	0
Reclassification from AOCI, tax expense (benefit)							0	0
Accumulated Other Comprehensive Income Including Portion Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net unrealized (loss) gain arising during the period							(28,135)	4,299
Reclassification of net realized gain into earnings							(2,439)	(6,755)
Other comprehensive (loss) income, net of tax							(30,574)	(2,456)
Accumulated other comprehensive (loss) income	$ 9,664			$ 41,398			9,664	41,398
AOCI Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Less: Other comprehensive loss attributable to non-controlling interests							920	(3,038)
Foreign Currency Translation Adjustments Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Less: Other comprehensive loss attributable to non-controlling interests							0	0
Hedging Activities Attributable to Noncontrolling Interest
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Less: Other comprehensive loss attributable to non-controlling interests							$ 920	$ (3,038)

Non-controlling Interests - Red

Non-controlling Interests - Redeemable Non-controlling Interests (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Jan. 01, 2019	Jan. 01, 2018
Redeemable Non-controlling Interests
Beginning balance			$ 33,495			$ 34,660	$ 33,495	$ 34,660
Cumulative-effect adjustment										$ 20,106
Net loss	$ (7,341)			$ 12,443			(14,241)	15,101
Distributions	(2,538)	$ (4,866)	$ (5,023)	(6,499)	$ (6,185)	$ (5,204)	(852)	(1,993)
Repurchases of redeemable non-controlling interests, net							(4,753)	617
Non-cash redemption of redeemable non-controlling interests							7,345	0
Ending balance	$ 20,994			$ 43,900			$ 20,994	$ 43,900
Redeemable Noncontrolling Interest
Redeemable Non-controlling Interests
Cumulative-effect adjustment									$ 0	$ (4,485)

Non-controlling Interests - Nar

Non-controlling Interests - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Noncontrolling Interest [Line Items]
Decline in noncontrolling interest balance		$ (151.2)
Distributed Generation | United states
Noncontrolling Interest [Line Items]
Repurchase of noncontrolling interest	$ 3.9
Ownership interest by parent	100.00%

Subsequent Events - Public Offe

Subsequent Events - Public Offering and Private Placement of Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Oct. 08, 2019	Jun. 12, 2018	Jun. 11, 2018	Sep. 30, 2019	Sep. 30, 2018
Subsequent Event [Line Items]
Proceeds from issuance of Class A common stock to affiliates		$ 650,000	$ 650,000	$ 0	$ 650,000
Subsequent Event | Public Offering
Subsequent Event [Line Items]
Public offering common stock (in shares)	14,907,573
Price of shares issued (in dollars per share)	$ 16.77
Proceeds from issuance of Class A common stock to affiliates	$ 250,000
Subsequent Event | Private Placement
Subsequent Event [Line Items]
Public offering common stock (in shares)	2,981,514
Price of shares issued (in dollars per share)	$ 16.77
Proceeds from issuance of Class A common stock to affiliates	$ 50,000
Affiliates of Brookfield | Subsequent Event
Subsequent Event [Line Items]
Percentage of ownership	61.00%
TerraForm Power | Affiliates of Brookfield | Subsequent Event
Subsequent Event [Line Items]
Percentage of ownership	61.00%

Subsequent Events - Amendment t

Subsequent Events - Amendment to the Revolver (Details) - Line of Credit	Oct. 08, 2019USD ($)	Sep. 30, 2019USD ($)lender
Revolving Credit Facility
Subsequent Event [Line Items]
Maximum borrowing capacity		$ 800,000,000
Number of new lenders | lender		3
Revolving Credit Facility | Subsequent Event
Subsequent Event [Line Items]
Increase in borrowing capacity	$ 200,000,000
Accordion feature	$ 150,000,000
Debt extension term	1 year
Letter of Credit
Subsequent Event [Line Items]
Maximum borrowing capacity		$ 300,000,000
Letter of Credit | Subsequent Event
Subsequent Event [Line Items]
Increase in borrowing capacity	$ 50,000,000

Subsequent Events - Private Off

Subsequent Events - Private Offering of Corporate Senior Notes (Details) - USD ($)	Oct. 16, 2019	Sep. 30, 2019
Secured Debt | Subsequent Event
Subsequent Event [Line Items]
Make whole premium plus accrued and unpaid interest	$ 25,500,000
Secured Debt | 4.75% Senior Notes Due in 2030 | Subsequent Event
Subsequent Event [Line Items]
Face amount of debt instrument	$ 700,000,000
Interest rate	4.75%
Issuance price percentage of face amount	100.00%
Secured Debt | Senior Notes due 2025
Subsequent Event [Line Items]
Interest rate		6.63%
Secured Debt | Senior Notes due 2025 | Subsequent Event
Subsequent Event [Line Items]
Extinguishment of debt	$ 300,000,000
Secured Debt | Term Loan | Subsequent Event
Subsequent Event [Line Items]
Extinguishment of debt	343,900,000
Interest Rate Swaps | Subsequent Event
Subsequent Event [Line Items]
Payment of derivative liabilities	$ 8,800,000

Subsequent Events - Solar LTSA

Subsequent Events - Solar LTSA (Details)	Nov. 01, 2019
SMA Solar Technology | Solar LTSA | Subsequent Event
Long-term Contract for Purchase of Electric Power [Line Items]
Long-term service agreement term	10 years

Subsequent Events - Transfer of

Subsequent Events - Transfer of Title of Delayed Projects (Details) $ in Thousands	Oct. 31, 2019USD ($)projectMW	Nov. 12, 2019USD ($)	Nov. 08, 2019USD ($)	Sep. 30, 2019USD ($)MW	Sep. 26, 2019USD ($)MW	Jul. 19, 2019USD ($)	Dec. 31, 2018USD ($)
Subsequent Event [Line Items]
Total consideration				$ 114,195			$ 0
WGL Acquisition
Subsequent Event [Line Items]
Nameplate capacity (MW) | MW				18	320
Total consideration					$ 114,195	$ 114,200
Subsequent Event | WGL Acquisition
Subsequent Event [Line Items]
Number of projects transferred to company | project	43
Release From Escrow	$ 68,800
Nameplate capacity (MW) | MW	18
Total consideration		$ 45,400	$ 45,400

Subsequent Events - Fourth Quar

Subsequent Events - Fourth Quarter Cash Distribution (Details) - $ / shares	Nov. 06, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Subsequent Event [Line Items]
Dividend declared (in dollars per share)		$ 0.2014	$ 0.2014	$ 0.2014	$ 0.19	$ 0.19	$ 0.19	$ 0.6042	$ 0.57
Subsequent Event
Subsequent Event [Line Items]
Dividend declared (in dollars per share)	$ 0.2014

Uncategorized Items - terp2019q

Label	Element	Value
Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 20,414,000
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	24,578,000
Noncontrolling Interest [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(308,000)
Non-Controlling Interests, Retained Earnings (Accumulated Deficit) [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ (308,000)