TerraForm Power NY (TERP) 10-Q7 May 152015 Q1 Quarterly reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information Document and Entity Information	3 Months Ended
	Mar. 31, 2015	1-May-15
Document Information [Line Items]
Entity Registrant Name	TerraForm Power, Inc.
Entity Central Index Key	1599947
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Amendment Flag	FALSE
Class A Common Stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		55,301,690
Class B common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		62,726,654
Class B1 common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		5,490,000

Unaudited_Consolidated_Stateme

Unaudited Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Income Statement [Abstract]
Operating revenues, net	$70,515		$11,880
Operating costs and expenses:
Cost of operations	16,820		460
Cost of operations - affiliate	3,643		352
General and administrative	9,939		98
General and administrative - affiliate	6,027		1,590
Acquisition and related costs	13,722		0
Acquisition and related costs - affiliate	436		0
Depreciation, accretion and amortization	31,891		3,241
Total operating costs and expenses	82,478		5,741
Operating (loss) income	-11,963		6,139
Other expenses:
Interest expense, net	36,855		7,082
Loss on extinguishment of debt, net	20,038		0
Loss on foreign currency exchange, net	14,369		595
Other, net	480		0
Total other expenses, net	71,742		7,677
Loss before income tax benefit	-83,705		-1,538
Income tax benefit	-45	[1]	-457	[1]
Net loss	-83,660		-1,081
Less: Predecessor loss prior to initial public offering on July 23, 2014	0		-720
Less: Net loss attributable to redeemable non-controlling interests	-169		0
Less: Net loss attributable to non-controlling interests	-55,375		-361
Net loss attributable to TerraForm Power, Inc. Class A common stockholders	($28,116)
Weighted average Class A common stock - Basic and Diluted (shares)	49,694
Net earnings (loss) per weighted average Class A common share - basic and diluted ($ per share)	($0.57)

[1]	Income tax benefit is not allocated to the Company's Solar and Wind segments.

Unaudited_Consolidated_Stateme1

Unaudited Consolidated Statements of Comprehensive Loss (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Comprehensive Income [Abstract]
Net loss	($83,660)	($1,081)
Foreign currency translation adjustments:
Net unrealized losses arising during the period	-3,275	0
Hedging activities:
Net unrealized losses arising during the period	-2,248	0
Reclassification of net losses into earnings	2,857	0
Other comprehensive loss, net of tax	-2,666	0
Total comprehensive loss	-86,326	-1,081
Less: Predecessor comprehensive loss prior to initial public offering on July 23, 2014	0	-3,391
Less: comprehensive loss attributable to non-controlling interests
Net loss attributable to non-controlling interests	-55,375	-361
Foreign currency translation adjustments	-1,862	0
Hedging activities	168	0
Comprehensive loss attributable to non-controlling interests	-57,069	-361
Comprehensive loss attributable to TerraForm Power, Inc. Class A stockholders	($29,257)	$2,671

Unaudited_Consolidated_Balance

Unaudited Consolidated Balance Sheets (USD $)	Mar. 31, 2015		Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Current assets:
Cash and cash equivalents	$153,423		$468,554
Restricted cash, including consolidated variable interest entities of $25,022 and $39,898 in 2015 and 2014, respectively	78,076		70,545
Accounts receivable, including consolidated variable interest entities of $25,650 and $16,921 in 2015 and 2014, respectively	58,258		31,986
Due from SunEdison and affiliates, net	18,155		0
Prepaid expenses and other current assets	29,274		22,620
Total current assets	337,186		593,705
Property and equipment, net, including consolidated variable interest entities of $1,539,607 and $1,466,223 in 2015 and 2014, respectively	3,429,630		2,554,904
Intangible assets, net, including consolidated variable interest entities of $234,954 and $259,004 in 2015 and 2014, respectively	454,928		361,673
Deferred financing costs, net	51,359		42,113
Deferred income taxes	87		4,606
Other assets	92,428		29,419
Total assets	4,365,618	[1]	3,586,420
Current liabilities:
Current portion of long-term debt and financing lease obligations, including consolidated variable interest entities of $20,986 and $20,907 in 2015 and 2014, respectively	229,517		84,104
Accounts payable, accrued expenses and other current liabilities, including consolidated variable interest entities of $27,060 and $27,284 in 2015 and 2014, respectively	81,146		82,605
Deferred revenue, including consolidated variable interest entities of $14,140 and $12,941 in 2015 and 2014, respectively	23,242		21,989
Due to SunEdison and affiliates, net	0		153,052
Total current liabilities	333,905		341,750
Other liabilities:
Long-term debt and financing lease obligations, less current portion, including consolidated variable interest entities of $621,336 and $620,853 in 2015 and 2014, respectively	1,965,161		1,568,517
Deferred revenue, including consolidated variable interest entities of $57,413 and $51,943 in 2015 and 2014, respectively	57,413		52,081
Deferred income taxes	5,983		7,702
Asset retirement obligations, including consolidated variable interest entities of $43,151 and $32,181 in 2015 and 2014, respectively	117,966		76,111
Other long-term liabilities	3,976		0
Total liabilities	2,484,404		2,046,161
Redeemable non-controlling interests	25,204		24,338
Stockholders' equity:
Preferred stock, $0.01 par value, 50,000 shares authorized, none issued and outstanding in 2015 and 2014	0		0
Additional paid-in capital	758,518		497,556
Accumulated deficit	-53,733		-25,617
Accumulated other comprehensive loss	-2,609		-1,637
Total TerraForm Power stockholders' equity	703,396		471,392
Non-controlling interests	1,152,614		1,044,529
Total stockholders' equity	1,856,010		1,515,921
Total liabilities, non-controlling interests and stockholders' equity	4,365,618		3,586,420
Class A Common Stock
Stockholders' equity:
Common Stock	535		387
Class B common stock
Stockholders' equity:
Common Stock	627		645
Class B1 common stock
Stockholders' equity:
Common Stock	$58		$58

[1]	Corporate assets include cash and cash equivalents; other current assets; corporate-level debt and related deferred financing costs, net and other assets.

Unaudited_Consolidated_Balance1

Unaudited Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Restricted cash	$78,076	$70,545
Accounts receivable	58,258	31,986
Assets, Noncurrent [Abstract]
Property and equipment, net	3,429,630	2,554,904
Intangible assets, net	454,928	361,673
Current liabilities:
Current portion of long-term debt	229,517	84,104
Accounts payable, accrued expenses and other current liabilities	81,146	82,605
Deferred revenue	23,242	21,989
Liabilities, Noncurrent [Abstract]
Long-term debt and financing lease obligations, less current portion	1,965,161	1,568,517
Deferred revenue	57,413	52,081
Asset retirement obligations	117,966	76,111
Par value (in dollars per share)	$0.01	$0.01
Shares authorized (in shares)	50,000,000	50,000,000
Shares issued (in shares)	0	0
Shares outstanding (in shares)	0	0
Shares outstanding (in shares)	124,518,344
Consolidated variable interest entities
Current assets:
Restricted cash	25,022	39,898
Accounts receivable	25,650	16,921
Assets, Noncurrent [Abstract]
Property and equipment, net	1,539,607	1,466,223
Intangible assets, net	234,954	259,004
Current liabilities:
Current portion of long-term debt	20,986	20,907
Accounts payable, accrued expenses and other current liabilities	27,060	27,284
Deferred revenue	14,140	12,941
Liabilities, Noncurrent [Abstract]
Long-term debt and financing lease obligations, less current portion	621,336	620,853
Deferred revenue	57,413	51,943
Asset retirement obligations	$43,151	$32,181
Class A Common Stock
Liabilities, Noncurrent [Abstract]
Par value (in dollars per share)	$0.01	$0.01
Shares authorized (in shares)	850,000,000	850,000,000
Shares issued (in shares)	55,952,000	42,218,000
Shares outstanding (in shares)	55,952,000	42,218,000
Class B common stock
Liabilities, Noncurrent [Abstract]
Par value (in dollars per share)	$0.01	$0.01
Shares authorized (in shares)	140,000,000	140,000,000
Shares issued (in shares)	62,727,000	64,526,000
Shares outstanding (in shares)	62,717,000	64,526,000
Class B1 common stock
Liabilities, Noncurrent [Abstract]
Par value (in dollars per share)	$0.01	$0.01
Shares authorized (in shares)	260,000,000	260,000,000
Shares issued (in shares)	5,840,000	5,840,000
Shares outstanding (in shares)	5,840,000	5,840,000

Unaudited_Consolidated_Stateme2

Unaudited Consolidated Statement of Stockholders' Equity (USD $)		Total	Class A Common Stock	Class B common stock	Class B1 common stock	Total - Parent		Preferred Stock	Common Stock	Common Stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit		Accumulated Other Comprehensive Income (Loss)	Total - Non-controlling Interests		Non-controlling Interests - Capital	Non-controlling Interests - Accumulated Deficit	Non-controlling Interests - Accumulated Other Comprehensive Income (Loss)
In Thousands, except Share data, unless otherwise specified		USD ($)				USD ($)		USD ($)	Class A Common Stock	Class B common stock	Class B1 common stock	USD ($)	USD ($)		USD ($)	USD ($)		USD ($)	USD ($)	USD ($)
									USD ($)	USD ($)	USD ($)
Beginning balance at Dec. 31, 2014		$1,515,921				$471,392		$0	$387	$645	$58	$497,556	($25,617)		($1,637)	$1,044,529		$1,092,809	($44,451)	($3,829)
Beginning balance (in shares) at Dec. 31, 2014			42,218,000	64,526,000	5,840,000				42,218,000	64,526,000	5,840,000
Preferred stock beginning balance at Dec. 31, 2014		0						0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class A common stock related to the public offering, net of issuance costs		342,192				342,192			138	-18		342,072
Issuance of Class A common stock related to the public offering, net of issuance costs (shares)									13,800,000	-1,799,000
Stock-based compensation		5,144				5,144			0			5,144
Net loss		-83,660				-28,116	[1]						-28,116	[1]		-55,375	[1]
Forfeitures of restricted stock									1			-1
Vesting of restricted stock									11			-11
Forfeitures of restricted stock (shares)									-66,000
Dividends		-15,125				-15,125						-15,125
Consolidation of non-controlling interests in acquired projects		114,442														114,442		114,442
Repurchase of non-controlling interest		-54,694														-54,694		-54,694
Contributions from SunEdison		53,020				22,872						22,872				30,148		30,148
Other Comprehensive Income		-2,666				-972									-972	-1,694				-1,694
Sale of membership interests in projects		10,096														10,096		10,096
Distributions to non-controlling interests		-28,829														-28,829		-28,829
Equity Reallocation		93,991				-93,991						-93,991				93,991
Net Income (Loss), Including Portion Attributable to Nonredeemable Noncontrolling Interest	[1]	-83,491
Ending balance at Mar. 31, 2015		$1,856,010				$703,396		$0	$535	$627	$58	$758,518	($53,733)		($2,609)	$1,152,614		$1,257,963	($99,826)	($5,523)
Ending balance (in shares) at Mar. 31, 2015		124,518,344	55,952,000	62,717,000	5,840,000				55,952,000	62,727,000	5,840,000
Preferred stock ending balance at Mar. 31, 2015		0						0

[1]	Excludes net loss attributable to redeemable non-controlling interests

Unaudited_Consolidated_Stateme3

Unaudited Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows from operating activities:
Net loss	($83,660)	($1,081)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Non-cash incentive revenue	-647	-127
Non-cash interest expense	317	81
Stock compensation expense	5,144	0
Depreciation, accretion and amortization	31,891	3,241
Amortization of intangible assets	-336	0
Amortization of deferred financing costs and debt discounts	7,709	488
Recognition of deferred revenue	-73	-64
Loss on extinguishment of debt	20,038	0
Unrealized loss on derivatives	4,302	0
Unrealized loss on foreign currency exchange	14,369	595
Deferred taxes	0	-451
Other, net	881	-348
Changes in assets and liabilities:
Accounts receivable	-20,985	-7,507
Prepaid expenses and other current assets	4,420	-7,470
Accounts payable, accrued interest, and other current liabilities	417	18,112
Deferred revenue	6,658	1,577
Due to SunEdison and affiliates	-390	-27,657
Restricted cash from operating activities	-664	0
Net cash used in operating activities	-10,609	-20,611
Cash flows from investing activities:
Cash paid to third parties for renewable energy facility construction	-82,758	-103,047
Other investments	-10,000	0
Acquisitions of renewable energy facilities from third parties, net of cash acquired	-810,720	-14,211
Due to SunEdison and affiliates	-15,079	0
Change in restricted cash	494	19,855
Net cash used in investing activities	-918,063	-97,403
Cash flows from financing activities:
Proceeds from issuance of Class A common stock	342,192	0
Change in restricted cash for principal debt service	0	538
Proceeds from Senior Notes	793,712	0
Repayment of term loan	-573,500	0
Borrowings of long-term debt	275,987	314,169
Principal payments on long-term debt	-2,910	-568
Due to SunEdison and affiliates, net	-148,998	4,514
Contributions from non-controlling interests	10,497	545
Distributions to non-controlling interests	-12,884	0
Repurchase of non-controlling interest	-54,694	0
Distributions to SunEdison and affiliates	-16,659	0
Net SunEdison investment	53,020	35,529
Payment of dividends	-15,125	0
Debt prepayment premium	-6,429	0
Payment of deferred financing costs	-30,667	-15,267
Net cash provided by financing activities	613,542	339,460
Net decrease in cash and cash equivalents	-315,130	221,446
Effect of exchange rate changes on cash and cash equivalents	-1	0
Cash and cash equivalents at beginning of period	468,554	1,044
Cash and cash equivalents at end of period	153,423	222,490
Supplemental Disclosures:
Cash paid for interest, net of amounts capitalized of $641 and $1,961, respectively	12,497	0
Cash paid for income taxes	0	0
Schedule of non-cash activities:
Additions of asset retirement obligation (ARO) assets and liabilities	23,815	0
ARO assets and obligations from acquisitions	17,705	0
Principal payments on long-term debt from solar renewable energy certificates	330	0
Long-term debt assumed in connection with acquisitions	$59,816	$0

Unaudited_Consolidated_Stateme4

Unaudited Consolidated Statements of Cash Flows (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Statement of Cash Flows [Abstract]
Interest capitalized	$641	$1,961

Nature_of_Operations

Nature of Operations	3 Months Ended
Nature of Operations	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Operations	NATURE OF OPERATIONS

	TerraForm Power, Inc. (the "Company") is a subsidiary of SunEdison, Inc. ("SunEdison"). The accompanying unaudited consolidated financial statements have been prepared in accordance with the Securities and Exchange Commission’s, or SEC’s, regulations for interim financial information. Accordingly, they do not include all of the information and notes required by U.S. generally accepted accounting principles ("U.S. GAAP") for complete financial statements. The following notes should be read in conjunction with the accounting policies and other disclosures as set forth in the notes to the Company’s annual financial statements for the year ended December 31, 2014. Interim results are not necessarily indicative of results for a full year.

	In the opinion of management, the accompanying unaudited consolidated financial statements contain all material adjustments consisting of normal and recurring accruals necessary to present fairly the Company's unaudited consolidated financial position as of March 31, 2015, and the results of operations, comprehensive income and cash flows for the three months ended March 31, 2015, and 2014.

Transactions_Between_Entities_

Transactions Between Entities Under Common Control	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Transactions Between Entities Under Common Control	When renewable energy facilities are acquired from SunEdison, the Company is required to recast its historical financial statements to reflect the assets and liabilities and the results of operations of the acquired renewable energy facilities for the period it was owned by SunEdison in accordance with rules applicable to transactions between entities under common control. During the first quarter of 2015, the Company acquired 19 solar energy facilities with a combined nameplate capacity of 161.1 MW from SunEdison, which resulted in a recast of the balance sheet as of December 31, 2014, and the related statement cash flows for the year ended December 31, 2014. The facilities were not in operations in 2014 and there was no impact to the statement of operations or accumulated other comprehensive loss for the year ended December 31, 2014.

	The following table presents the changes to previously reported amounts of the Company's consolidated balance sheet as of December 31, 2014 included in the Company's Annual Report on Form 10-K:


	(In thousands)	December 31, 2014 As Reported			Acquired Call Rights Projects			December 31, 2014 Recast
	Balance Sheet Caption
	Cash and cash equivalents	$	468,393		$	161		$	468,554

	Due from SunEdison and affiliates, net	19,640			(19,640		)	—

	Prepaid expenses and other current assets	21,840			780			22,620

	Property and equipment, net	2,327,803			227,101			2,554,904

	Change in total assets				$	208,402


	Current portion of long-term debt	$	80,133		$	3,971		$	84,104

	Accounts payable, accrued expenses and other current liabilities	81,781			824			82,605

	Due to SunEdison and affiliates, net	—			153,052			153,052

	Long-term debt and financing lease obligations, less current portion	1,517,962			50,555			1,568,517

	Change in total liabilities				$	208,402


	The following table presents the changes to previously reported amounts of the Company's consolidated statement of cash flows for the year ended December 31, 2014, included in the Company's Annual Report on Form 10-K:


	(In thousands)	December 31, 2014 As Reported			Acquired Call Rights Projects			December 31, 2014 Recast
	Cash Flows Caption
	Changes in assets and liabilities:
	VAT receivable, prepaid expenses and other current assets	$	23,730		$	(819	)	$	22,911

	Accounts payable, accrued interest, and other current liabilities	3,371			865			4,236

	Cash flows from investing activities:
	Cash paid to SunEdison and third parties for solar generation facility construction	(816,682		)	(236,189		)	(1,052,871		)
	Deposit for acquisition of Call Right Projects	(34,000		)	34,000			—

	Cash flows from financing activities:
	Borrowings of long-term debt	399,806			62,111			461,917

	Principal payments on long-term debt	(341,336		)	1,766			(339,570		)

	Net increase in cash and cash equivalents	467,513			427			467,940

	Effect of exchange rate changes on cash and cash equivalents	(164		)	(266		)	(430		)
	Cash and cash equivalents at end of period	468,393			161			468,554


	The amounts previously reported in the Company's consolidated statement of cash flows for the three months ended March 31, 2014 have been recast to reflect a $4,514 increase in cash paid to SunEdison and third parties within cash flows from investing activities and $4,514 of cash proceeds from SunEdison and affiliates within financing activities. The facilities were not in operations during 2014 and there was no impact to the statement of operations or accumulated other comprehensive loss for the three months ended March 31, 2014.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

	Use of Estimates

	In preparing the unaudited consolidated financial statements, the Company used estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements. Such estimates also affect the reported amounts of revenues, expenses and cash flows during the reporting period. Actual results may differ from estimates under different assumptions or conditions.

	Recent Accounting Pronouncements

	In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. This standard will become effective for us on January 1, 2018. Early application is permitted but not before January 1, 2017. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is currently evaluating the effect that ASU No. 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method or determined the effect of the standard on its ongoing financial reporting.

	In February 2015, the FASB issued ASU No. 2015-02 Consolidation (Topic 810) Amendments to the Consolidation Analysis, which affects the following areas of the consolidation analysis: limited partnerships and similar entities, evaluation of fees paid to a decision maker or service provider as a variable interest and in determination of the primary beneficiary, effect of related parties on the primary beneficiary determination and for certain investment funds. ASU No. 2015-02 is effective for us for our fiscal year ending December 31, 2016 and interim periods therein. We are evaluating the impact of this standard on our consolidated statements of financial position, results of operations and cash flows.

	In April 2015, the FASB issued ASU No. 2015-03 Interest - Imputation of Interest (Subtopic 835-30) Simplifying the Presentation of Debt Issuance Costs, which requires debt issuance costs related to a recognized debt liability to be presented on the balance sheet as a direct deduction from the debt liability. ASU No. 2015-03 is effective for us for our fiscal year ending December 31, 2016 and interim periods therein. We are evaluating the impact of this standard on our consolidated balance sheet.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Acquisitions	ACQUISITIONS

	2015 Acquisitions

	Acquisition of First Wind

	On January 29, 2015, the Company, through Terra LLC, acquired from First Wind Holdings, LLC (together with its subsidiaries, “First Wind”) 521.1 MW of operating power assets, including 500.0 MW of wind power assets and 21.1 MW of solar power assets (the “First Wind acquisition”). The operating power assets the Company acquired are located in Maine, New York, Hawaii, Vermont and Massachusetts. The purchase price for this acquisition was $810.4 million, net of cash acquired. The initial accounting for this acquisition is not complete because the evaluation necessary to assess the fair values of certain net assets acquired is still in process. The provisional amounts for this acquisition, included in the table within the "Acquisition Accounting" section of this footnote below, are subject to revision until the evaluations are completed.

	The operating revenues and net loss of the acquired facilities reflected in the accompanying unaudited consolidated statement of operations for the three months ended March 31, 2015 were $22.1 million and $6.2 million, respectively.

	The following unaudited pro forma supplementary data presented in the table below gives effect to the 2014 Acquisitions as if the transactions had occurred on January 1, 2013 and the First Wind Acquisition as if the transaction had occurred on January 1, 2014. The 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 acquisitions been consummated on the date assumed or of the Company’s results of operations for any future date.


		Three Months Ended March 31,
	(In thousands, unaudited)	2015			2014
	Total operating revenues, net	$	39,851		$	58,281

	Net loss	6,987			21,987


	Acquisition costs, including amounts for affiliates, related to the transactions above were $14.2 million for the three months ended March 31, 2015 and are reflected as acquisition and related costs in the accompanying unaudited consolidated statements of operations. There were no acquisition costs for the three months ended March 31, 2014.

	Acquisition of Atlantic Power Corporation wind power plants

	On March 31, 2015, the Company signed a definitive agreement to acquire 521.0 MW of operating wind power assets located in Idaho and Oklahoma from Atlantic Power Corporation, for total cash consideration of $350.0 million. The assets are contracted under long term PPAs with investment grade utilities with a weighted-average credit rating of A3 and a weighted-average remaining life of 18 years. The Company is pursuing funding for the acquisition through a drop down warehouse facility in partnership with third party equity investors and SunEdison. The assets would initially be acquired by the warehouse and the Company would be offered call rights to acquire the assets in the future.

	2014 Acquisitions

	Final

	During the year ended December 31, 2014, the Company through various transactions, acquired the following renewable energy facilities: Nellis, CalRENEW-1, Atwell Island, Summit Solar Projects and MA Operating. The acquisition accounting for the acquisitions of these facilities was completed as of March 31, 2015, at which point the provisional fair values became final. The final estimated fair value of assets, liabilities and non-controlling interests is included in the table within the "Acquisition Accounting" section of this footnote below and reflects no material changes except for the following reallocations: a decrease to property and equipment of $4.9 million, an increase to intangible assets of $3.2 million, a decrease to accounts payable of $2.5 million and a total decrease for all other accounts of $0.7 million.

	Preliminary

	During the year ended December 31, 2014, the Company through various transactions, acquired the following renewable energy facilities: Stonehenge Operating Projects, Mt. Signal, Hudson Energy and Capital Dynamics. The initial accounting for these acquisitions is not complete because the evaluation necessary to assess the fair values of certain net assets acquired is still in process. The provisional amounts for these acquisitions, included in the table within the "Acquisition Accounting" section of this footnote below, are subject to revision until the evaluations are completed.

	Acquisition Accounting

	The estimated fair values of assets, liabilities and non-controlling interests as of March 31, 2015, are as follows:


		2015 Preliminary			2014 Preliminary									2014 Final			Total Allocation
	(In thousands)	First Wind			Mt. Signal			Capital Dynamics			Other			Other
	Property and equipment	$	803,103		$	649,005		$	216,771		$	102,788		$	150,934		$	1,922,601

	Accounts receivable	9,378			11,617			2,309			7,100			2,380			32,784

	Restricted cash	6,630			22,165			15			5,564			9,156			43,530

	Deferred income taxes	—			—			21,118			—			—			21,118

	Other assets	68,671			12,621			1,490			1,455			3,896			88,133

	Intangible assets	125,671			117,925			71,859			21,656			105,361			442,472

	Total assets acquired	1,013,453			813,333			313,562			138,563			271,727			2,550,638

	Long-term debt	59,816			413,464			—			65,084			72,930			611,294

	Accounts payable, accrued expenses and other current liabilities	9,934			24,813			1,194			3,499			1,286			40,726

	Asset retirement obligations	12,403			4,656			13,073			6,622			10,752			47,506

	Deferred income taxes	—			—			25,191			990			—			26,181

Total liabilities assumed	82,153			442,933			39,458			76,195			84,968			725,707

Non-controlling interest	120,864			78,745			16,600			2,850			1,400			220,459

Purchase price, net of cash acquired	$	810,436		$	291,655		$	257,504		$	59,518		$	185,359		$	1,604,472


The acquired renewable energy facilities' non-financial assets represent estimates of the fair value of acquired power purchase agreements (PPAs) based on significant inputs that are not observable in the market and thus represent a Level 3 measurement. The estimated fair values were determined based on an income approach and the estimated useful lives of the intangible assets range from 10 to 25 years. See Note 6. Intangible Assets for additional disclosures related to the acquired intangible assets.

Acquisitions of Call Right Projects

The assets and liabilities transferred to the Company for the acquisitions listed below relate to interests under common control with SunEdison and accordingly, were recorded at historical cost basis. The difference between the cash purchase price and historical cost basis of the net assets acquired was recorded as a distribution to SunEdison and reduced the balance of its non-controlling interest.

Acquisition of U.K. Call Right Projects

During March 2015, the Company acquired eleven renewable energy facilities including an extension to our Crundale facility. The facilities are located in England and Wales and have a combined nameplate capacity of 152.1 MW. The Company paid $81.9 million in cash and assumed $174.3 million of short-term financing to acquire these renewable energy facilities from subsidiaries of SunEdison in a series of transactions. The extension was acquired by the Company exercising its option to acquire a 5.9 MW solar expansion under the terms of the amended engineering, procurement and construction contract. The remaining acquired facilities were Call Right Projects pursuant to the Support Agreement with SunEdison, see further discussion in Note 17. Related Parties.

Additions to DG 2014 Portfolio 1 and DG 2015 Portfolio 2

During the three months ended March 31, 2015, the Company acquired additional renewable energy facilities within the DG 2014 Portfolio 1 and the DG 2015 Portfolio 2, totaling 6.2 MW and 8.8 MW, respectively. As of March 31, 2015, the Company had paid the initial amounts due of $18.0 million to acquire these renewable energy facilities from subsidiaries of SunEdison in a series of transactions and assumed $1.9 million of revolving debt. The Company estimates that the final amounts due for these acquisitions will be $8.7 million, which are scheduled to be paid during the second quarter of 2015. The acquired facilities were Call Right Projects pursuant to the Support Agreement with SunEdison.

The following table is a summary of assets and liabilities acquired from SunEdison in connection with these Call Right Projects:


(in thousands)		As of March 31, 2015
Current assets		$	19,424

Property, plant and equipment		274,685

Non-current assets		24,912

Total assets acquired		319,021

Long-term debt		174,467

Other liabilities		71,592

Total liabilities assumed		246,059

Net assets acquired		$	72,962

Cash Paid		$	89,621

Adjustments to equity reflected as distribution to non-controlling interests		16,659


Subsequent Events

Acquisitions of Call Right Projects

On April 28, 2015, the Company acquired a solar energy facility within the DG 2015 Portfolio 2 with a nameplate capacity of 3.2 MW. The Company paid the initial amount due of $2.3 million to acquire this facility from subsidiaries of SunEdison. The Company estimates that the final amount due for this acquisition will be $3.9 million, which is scheduled to be paid during the second quarter of 2015.The acquired facility was a Call Right Project pursuant to the Support Agreement with SunEdison.

On April 29, 2015, the Company acquired two additional solar energy facilities with a combined nameplate capacity of 23.5 MW which are located in England. The Company paid $9.8 million in cash and assumed $31.2 million of construction debt to acquire these renewable energy facilities from subsidiaries of SunEdison. The acquired facilities were Call Right Projects pursuant to the Support Agreement with SunEdison.

Property_and_Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Property and Equipment	PROPERTY AND EQUIPMENT

	Property and equipment, net consists of the following:


		March 31, 2015			December 31, 2014
	(In thousands)
	Renewable energy facilities	$	3,404,264		$	2,220,401

	Less accumulated depreciation - renewable energy facilities	(74,957		)	(50,080		)
	Property and equipment, net	3,329,307			2,170,321

	Construction in progress - renewable energy facilities	100,323			384,583

	Total property and equipment	$	3,429,630		$	2,554,904


	The Company recorded depreciation expense related to property and equipment of $25.1 million and $3.1 million for the three months ended March 31, 2015 and 2014, respectively. Construction in progress represents $100.3 million of costs incurred to complete the construction of the facilities in the Company's current portfolio that were either contributed to the Company by SunEdison or acquired from SunEdison.

	When projects are contributed or sold to the Company after completion by SunEdison, the Company retroactively recasts its historical financial statements to present the construction activity as if it consolidated the facility at inception of the construction. All construction in progress costs are stated at SunEdison's historical cost. These costs include capitalized interest costs and amortization of deferred financing costs incurred during the asset's construction period, which totaled $641 and $2,110 for the three months ended March 31, 2015 and 2014, respectively.

Intangible_Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	INTANGIBLE ASSETS

	The following table presents the gross carrying amount and accumulated amortization of intangible assets as of March 31, 2015:


	(In thousands, except weighted average amortization period)	Weighted Average Amortization Period	Gross Carrying Amount		Accumulated Amortization			Accumulated Currency Translation Adjustment			Net Book Value
	Energy revenue contracts	20 years	$	463,636	$	(5,329	)	$	(3,379	)	$	454,928


	The following table presents the gross carrying amount and accumulated amortization of intangible assets as of December 31, 2014:


	(In thousands, except weighted average amortization period)	Weighted Average Amortization Period	Gross Carrying Amount		Accumulated Amortization			Accumulated Currency Translation Adjustment			Net Book Value
	Energy revenue contracts	21 years	$	371,765	$	(6,169	)	$	(3,923	)	$	361,673


	As of March 31, 2015, the Company had energy revenue contracts representing long-term electricity sales agreements that were obtained through acquisitions (see Note. 4 Acquisitions). Energy revenue contracts are amortized on a straight-line basis over the remaining life of the agreements, which range from 10 to 25 years. Amortization expense related to the energy revenue contracts is recorded on the unaudited consolidated statements of operations as either a reduction or increase of energy revenue when the contract rate is above or below market rates or within depreciation, accretion and amortization expense when the contract rate is equal to market rates. Amortization expense was $5,329 during the three months ended March 31, 2015, $336 of which was an increase in energy revenue and $5,665 of which was recorded as depreciation, accretion and amortization expense in the accompanying unaudited consolidated statement of operations. There was no amortization expense during the three months ended March 31, 2014.

Variable_Interest_Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	VARIABLE INTEREST ENTITIES

	The Company is the primary beneficiary of ten VIEs in renewable energy facilities that were consolidated as of March 31, 2015, nine of which existed and were consolidated as of December 31, 2014. 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. No VIEs were deconsolidated during the three months ended March 31, 2015 and 2014.

	The carrying amounts and classification of the consolidated VIEs’ assets and liabilities included in the Company's unaudited consolidated balance sheet are as follows:


	(In thousands)	March 31, 2015		December 31, 2014
	Current assets	$	64,973	$	69,955

	Noncurrent assets	1,803,709		1,756,276

	Total assets	$	1,868,682	$	1,826,231

	Current liabilities	$	57,898	$	64,324

	Noncurrent liabilities	729,644		707,989

	Total liabilities	$	787,542	$	772,313


	The amounts shown above in the table exclude any potential VIEs under the First Wind acquisition as we have not completed the accounting related to this business combination. All of the assets in the table above are restricted for settlement of the VIE obligations, and all of the liabilities in the table above can only be settled by using VIE resources.

Longterm_Debt

Long-term Debt	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Long-term Debt	LONG-TERM DEBT

	Long-term debt consists of the following:


	(in thousands, except rates)		March 31, 2015				December 31, 2014				Interest Type	Current Interest Rate %		Financing Type

	Description:
	Corporate-level long-term debt:
	Term Loan, due 2019		$	—			$	573,500			Variable	5.3 (1)		Term debt

	Senior Notes, due 2023		800,000				—				Fixed	5.9		Senior notes

	Revolver		150,000				—				Variable	2.7		Revolving loan

	Project-level long-term debt:
	Permanent financing		882,865				886,149				-2	6.1 (3)		Term debt / Senior notes

	Construction financing		212,072				97,518				Variable	2.9 (3)		Construction debt

	Financing lease obligations		154,716				93,981				Imputed	5.1 (3)		Financing lease obligations

	Total Principal long-term debt and financing lease obligations		$	2,199,653			$	1,651,148				5.9 (3)

	Less current maturities		(229,517		)		(84,104		)
	Net unamortized (discount) premium		(4,975		)		1,473

	Long-term debt and financing lease obligations, less current portion		$	1,965,161			$	1,568,517

	———
	(1) The Company entered into an interest rate swap agreement (see Note 10. Derivatives) fixing the interest rate at 5.33%, which was terminated upon repayment of the Term Loan.
	(2) Includes debt at variable or fixed interest rates. As of March 31, 2015, 38% of this balance had a variable interest rate and 62% of this balance had a fixed interest rate.
	(3) Represents the weighted average effective interest rate as of March 31, 2015.

	Corporate-level Financing Arrangements

	Term Loan

	On January 28, 2015, the Company repaid the remaining outstanding principal balance on the Term Loan of $573.5 million. The Company recognized a $12.0 million loss on the extinguishment of debt during the three months ended March 31, 2015, as a result of this repayment.

	Revolving Credit Facilities

	On January 28, 2015, the Company replaced its existing revolver with a new $550.0 million revolving credit facility (the "Revolver"). The Revolver consists of a revolving credit facility in an amount of at least $550.0 million (available for revolving loans and letters of credit) and permits Terra Operating LLC to increase commitments to up to $725.0 million in the aggregate, subject to customary closing conditions. The Company recognized a $1.3 million loss on the extinguishment of debt during the three months ended March 31, 2015 as a result of the exchange.

	On May 1, 2015, the Company exercised its option to increase its borrowing capacity under the Revolver by $100.0 million. As a result of this transaction, the Company now has a total borrowing capacity of $650.0 million under the Revolver.

	The Revolver matures on January 27, 2020. Each of Terra Operating LLC's existing and subsequently acquired or organized domestic restricted subsidiaries (excluding non-recourse subsidiaries) and Terra LLC are or will become guarantors under the Revolver.

	At Terra Operating LLC’s option, all outstanding amounts under the Revolver will bear interest initially at a rate per annum equal to either (i) a base rate plus a margin of 1.50% or (ii) a reserve adjusted Eurodollar rate plus a margin of 2.50%. After the fiscal quarter ended June 30, 2015, the base rate margin will range between 1.25% and 1.75% and the Eurodollar rate margin will range between 2.25% and 2.75% as determined by reference to a leverage-based grid.

	The Revolver provides for voluntary prepayments, in whole or in part, subject to notice periods, and requires Terra Operating LLC to prepay outstanding borrowings in an amount equal to 100% of the net cash proceeds received by Terra LLC or its restricted subsidiaries from the incurrence of indebtedness not permitted by the Revolver by Terra Operating LLC or its restricted subsidiaries.

	The Revolver, each guaranty and any interest rate, currency hedging or hedging of Renewable Energy Certificate ("REC") obligations of Terra Operating LLC or any guarantor owed to the administrative agent, any arranger or any lender under the Revolver is secured by first priority security interests in (i) all of Terra Operating LLC's and each guarantor’s assets, (ii) 100% of the capital stock of each of Terra Operating LLC’s and its domestic restricted subsidiaries and 65% of the capital stock of Terra Operating LLC’s foreign restricted subsidiaries, and (iii) all intercompany debt. Notwithstanding the foregoing, collateral under the Revolver excludes the capital stock of non-recourse subsidiaries.

	Senior Notes

	On January 28, 2015, through our indirect subsidiary, Terra Operating LLC, the Company issued $800.0 million of 5.875% senior notes due 2023 at a price of 99.214% or the "Senior Notes." Terra Operating LLC used the net proceeds from the offering to fund a portion of the price of the First Wind acquisition. The Senior Notes are senior obligations of Terra Operating LLC and are guaranteed by Terra LLC and each of Terra Operating LLC's existing and future subsidiaries that guarantee its senior secured credit facility, subject to certain exceptions. Interest on the Senior Notes is payable on February 1 and August 1 of each year, beginning on August 1, 2015.

	Bridge Facility

	On March 31, 2015, the Company entered into an agreement with Morgan Stanley Senior Funding, Inc. which provides the Company with up to $515.0 million of senior unsecured bridge facility (the "Bridge Facility"). The Bridge Facility may be used by the Company, subject to certain conditions, to fund acquisitions, to repay certain indebtedness of acquisition facilities and to pay related fees and expenses. On April 20, 2015, the Bridge Facility was amended to add Citigroup Global Markets Inc., Barclays Capital Inc. and J.P. Morgan Securities LLC as participants to the Bridge Facility in addition to Morgan Stanley Senior Funding, Inc.

	Project-level Financing Arrangements

The Company's renewable energy facilities have long-term debt obligations in separate legal entities. The Company typically finances its renewable energy facilities through project entity specific debt secured by the renewable energy facility's assets (mainly the renewable energy facility) with no recourse to the Company. Typically, these financing arrangements provide for a construction loan, which upon completion may or may not be converted into a term loan.

Financing Lease Obligations

In certain transactions, the Company accounts for the proceeds of sale leasebacks as financings, which are typically secured by the renewable energy facility asset and its future cash flows from energy sales, and without recourse to the Company under the terms of the arrangement.

Bull Hill Financing

As a result of the First Wind acquisition, the Company assumed $59.8 million of financing lease obligations. The financing lease obligations assumed by the Company include those pursuant to a sale-leaseback agreement, entered into by First Wind on November 21, 2012, whereby First Wind sold substantially all of the property, plant and equipment of the Bull Hill facility to a financial institution and simultaneously entered into a long-term lease with that financial institution for the use of the assets. Under the terms of the agreement, the Company will continue to operate the wind facility and has the option to extend the lease or repurchase the assets sold at the end of the lease term. The sale-leaseback transaction was accounted for as a failed sale and the remaining obligations as of the date of the First Wind acquisition have been recorded as a financing lease obligation.

First Wind Debt Extinguishments

As part of the First Wind acquisition, the Company repaid certain long-term indebtedness of the First Wind Operating Entities. The Company recognized a loss on the extinguishment of debt of $6.4 million during the three months ended March 31, 2015 as a result of this repayment.

Maturities

The aggregate amounts of payments on long-term debt including financing lease obligations, and excluding amortization of debt discounts, due after March 31, 2015 are as follows:


(In thousands)	Remainder of 2015 (1)				2016 (2)				2017			2018			2019		Thereafter		Total
Maturities of long-term debt as of March 31, 2015	$	227,879			$	264,521			$	37,902		$	39,337		$	50,104	$	1,579,910	$	2,199,653

———
(1) The amount of long-term debt due in 2015 includes CAD 47.8 million (USD $37.8 million) of construction debt for SunE Perpetual Lindsay, which will be repaid by SunEdison in the third quarter of 2015 and an outstanding balance of $150.0 million on our Revolver.
(2) The amount of long-term debt due in 2016 includes GBP 152.5 million (USD $225.6 million) of debt for the Fairwinds & Crundale facilities and the U.K. Call Right Projects.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES

	Effective Tax Rate

	The income tax provision consisted of the following:


		Three Months Ended March 31,
	(In thousands, except effective tax rate)	2015			2014
	Loss before income tax benefit	$	(83,705	)	$	(1,538	)
	Income tax benefit	(45		)	(457		)
	Effective tax rate	0.1		%	29.7		%

	As of March 31, 2015, the Company owns 44.9% of Terra LLC and consolidates the results of Terra LLC through its controlling interest. The Company records SunEdison's 50.4% and Riverstone's 4.7% ownership of Terra LLC as a non-controlling interests in the financial statements. Terra LLC is treated as a partnership for income tax purposes. As such, the Company records income tax on its 44.9% of Terra LLC's taxable income and SunEdison records income tax on its 50.4% share of taxable income generated by Terra LLC.

	For the three months ended March 31, 2015, the overall effective tax rate was different than the statutory rate of 35% primarily due to the recording of a valuation allowance on certain tax benefits attributed to the Company and to lower statutory income tax rates in our foreign jurisdictions. For the three months ended March 31, 2014, the tax benefits for losses realized prior to the IPO were recognized primarily because of existing deferred tax liabilities. As of March 31, 2015, most jurisdictions are in a net deferred tax asset position. A valuation allowance is recorded against the deferred tax assets primarily because of the history of losses in those jurisdictions.

Derivatives

Derivatives	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	DERIVATIVES

	As part of the Company’s risk management strategy, the Company has entered into derivative instruments which include interest rate swaps, foreign currency contracts and commodity contracts to mitigate interest rate, foreign currency and commodity price exposure. If the Company elects to do so and if the instrument meets the criteria specified in Accounting Standards Codification ("ASC") 815, Derivatives and Hedging, the Company designates its derivative instruments as cash flow hedges. The Company enters into interest rate swap agreements in order to hedge the variability of expected future cash interest payments. Foreign currency contracts are used to reduce risks arising from the change in fair value of certain foreign currency denominated assets and liabilities. The objective of these practices is to minimize the impact of foreign currency fluctuations on operating results. The Company also enters into commodity contracts to economically hedge price variability inherent in electricity sales arrangements. The objectives of these transactions are to minimize the impact of variability in spot electricity prices and stabilize estimated revenue streams. The Company does not use derivative instruments for speculative purposes.

	As of March 31, 2015 and December 31, 2014, fair values of the following derivative instruments were included in the line items indicated.


			Fair Value of Derivative Instruments
			Hedging Contracts				Derivatives Not Designated as Hedges
	(In thousands)		Interest Rate Swaps				Interest Rate Swaps				Foreign Currency Contracts			Commodity Contracts			Gross Amounts of Assets/Liabilities Recognized				Gross Amounts Offset in Consolidated Balance Sheet			Net Amounts in Consolidated Balance Sheet
	As of March 31, 2015
	Prepaid expenses and other current assets		$	—			$	—			$	2,669		$	8,482		$	11,151			$	(1,155	)	$	9,996

	Other assets		—				—				1,861			31,970			33,831				(781		)	33,050

	Total assets		$	—			$	—			$	4,530		$	40,452		$	44,982			$	(1,936	)	$	43,046

	Accounts payable and other current liabilities		$	845			$	—			$	—		$	—		$	845			$	—		$	845

	Other long-term liabilities		470				1,381				3,711			—			5,562				(1,936		)	3,626

	Total liabilities		$	1,315			$	1,381			$	3,711		$	—		$	6,407			$	(1,936	)	$	4,471


	As of December 31, 2014
	Prepaid expenses and other current assets		$	—			$	—			$	—		$	—		$	—			$	—		$	—

	Other assets		—				—				1,811			—			1,811				—			1,811

	Total assets		$	—			$	—			$	1,811		$	—		$	1,811			$	—		$	1,811

	Accounts payable and other current liabilities		$	1,925			$	1,279			$	685		$	—		$	3,889			$	—		$	3,889

	Other long-term liabilities		—				—				—			—			—				—			—

	Total liabilities		$	1,925			$	1,279			$	685		$	—		$	3,889			$	—		$	3,889


	As of March 31, 2015 and December 31, 2014, notional amounts for derivative instruments consisted of the following:


			Notional Amount as of
	(In thousands)		March 31, 2015				December 31, 2014
	Derivatives designated as hedges:
	Interest rate swaps (USD)		$	50,150			$	349,213

	Derivatives not designated as hedges:
	Interest rate swaps (USD)		16,857				16,861

	Foreign currency contracts (GBP)		56,348				58,710

	Foreign currency contracts (CAD)		25,097				25,415

	Commodity contracts (MWhs)		2,248				—


	The Company has elected to net derivative assets and liabilities on the balance sheet as a right to setoff exists. For interest rate swaps, the Company has a master netting arrangement with only one counterparty, however, no amounts were netted under this arrangement as each of the interest rate swaps subject to this arrangement were in a loss position as of March 31, 2015. For foreign currency contracts, amounts are netted by currency in accordance with a master netting arrangement. For commodity contracts, the Company has a master netting arrangement, however, no amounts were netted under this arrangement as each of the commodity contracts subject to this arrangement were in a gain position as of March 31, 2015.

	Gains and losses on derivatives not designated as hedges for the three months ended March 31, 2015 and 2014 consisted of the following:


					Three Months Ended March 31,
	(In thousands)		Location of Loss Recognized in Income		2015				2014
	Interest rate swaps		Interest expense, net		$	236			$	—

Foreign currency contracts		Loss on foreign currency exchange, net		97				—

Commodity contracts		Operating revenues, net		4,259				—


Losses recognized related to interest rate swaps designated as cash flow hedges for the three months ended March 31, 2015 and 2014 consisted of the following:


		Three Months Ended March 31,
		Loss Recognized in Other Comprehensive Income (Effective Portion)							Location of Loss Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)		Amount of Loss Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)					Amount of Loss Recognized in Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)
(In thousands)		2015			2014						2015		2014			2015			2014
Interest rate swaps		$	2,248		$	—			Interest expense, net		$	2,857	$	—		$	—		$	—


As of March 31, 2015, the Company has posted letters of credit in the amount of $19.5 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 December 31, 2014 related to our derivative transactions.

Derivatives Designated as Hedges

Interest Rate Swaps

In September 2014, the Company entered into an interest rate swap agreement to hedge floating rate debt under the Term Loan. The interest rate swap qualified for hedge accounting and was designated as a cash flow hedge. Under the interest rate swap agreement, the Company paid a fixed rate and the counterparty to the agreement paid the Company a floating interest rate. This interest rate swap agreement was terminated on January 28, 2015 due to the extinguishment of the Term Loan by the Company on the same date, as discussed in Note 8. Long-term Debt. Due to the termination of the Term Loan, the Company reclassified the loss of $2.5 million that was previously deferred in other comprehensive income into earnings as the forecasted transaction is considered probable of not occurring. The reclassified amounts were recorded in interest expense, net during the current period. Additionally, the Company recognized a loss of extinguishment of debt of $0.3 million during the three months ended March 31, 2015 for fees incurred to terminate the interest rate swap.

The Company has an interest rate swap agreement to hedge floating rate project-level debt. This interest rate swap qualifies for hedge accounting and was designated as a cash flow hedge. Under the interest rate swap agreement, the project pays a fixed rate and the counterparty to the agreement pays a floating interest rate. The amounts deferred in other comprehensive income and reclassified into earnings during the period related to the interest rate swap are provided in the table above. The loss expected to be reclassified into earnings over the next twelve months is approximately $0.8 million.

Derivatives Not Designated as Hedges

Interest Rate Swaps

The Company has interest rate swap agreements that are economic hedges for project-level debt. These interest rate swaps are used to hedge floating rate debt. Under the interest rate swap agreements, the projects pay a fixed rate and the counterparties to the agreements pay a floating interest rate. As these hedges are not accounted for under hedge accounting, the changes in fair value are recorded in interest expense, net in the unaudited consolidated statement of operations, as provided in the table above.

Foreign Currency Contracts

The Company has foreign currency contracts in order to economically hedge its exposure to foreign currency fluctuations. The settlement of these hedges occurs on a quarterly basis through maturity. As these hedges are not accounted for under hedge accounting, the changes in fair value are recorded in loss/(gain) on foreign currency exchange, net in the unaudited consolidated statement of operations, as provided in the table above.

Commodity Contracts

In first quarter 2015, the Company acquired commodity contracts through its acquisition of First Wind. These agreements economically hedge commodity price variability inherent in certain electricity sales arrangements. If the Company sells electricity to an independent system operator market and there is no PPA available, it may enter into a commodity contract to hedge all or a portion of their estimated revenue stream. These commodity contracts require periodic settlements in which the Company receives a fixed price based on specified quantities of electricity and pays the counterparty a floating market price based on the same specified quantity of electricity. As these hedges are not accounted for under hedge accounting, the changes in fair value are recorded in operating revenues net, in the unaudited consolidated statement of operations, as provided in the table above.

Fair_Value_of_Financial_Instru

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS

	The carrying amount and estimated fair value of the Company's long-term debt as of March 31, 2015 and December 31, 2014 is as follows:



			As of March 31, 2015						As of December 31, 2014
	(In thousands)		Carrying Amount			Fair Value			Carrying Amount			Fair Value
	Long-term debt, including current portion		$	2,194,678		$	2,249,970		$	1,652,621		$	1,659,883


	The fair value of the Company's long-term debt was determined using inputs classified as Level 2 and a discounted cash flow approach using market rates for similar debt instruments.

	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 accompanying unaudited consolidated balance sheet:



	(In thousands)	As of March 31, 2015												As of December 31, 2014
	Assets	Level 1			Level 2			Level 3			Total			Level 1		Level 2		Level 3		Total
	Foreign currency contracts	$	—		$	2,594		$	—		$	2,594		$	—	$	1,811	$	—	$	1,811

	Commodity contracts	—			$	40,452		$	—		40,452			—		—		—		—

	Total derivative assets	$	—		$	43,046		$	—		$	43,046		$	—	$	1,811	$	—	$	1,811

	Liabilities
	Interest rate swaps	$	—		$	2,696		$	—		$	2,696		$	—	$	3,204	$	—	$	3,204

	Foreign currency contracts	—			1,775			—			1,775			—		685		—		685

	Total derivative liabilities	$	—		$	4,471		$	—		$	4,471		$	—	$	3,889	$	—	$	3,889


	The fair value of assets and liabilities are determined using either unadjusted quoted prices in active markets (Level 1) or pricing inputs that are observable (Level 2) whenever that information is available and using unobservable inputs (Level 3) to estimate fair value only when relevant observable inputs are not available. The Company uses valuation techniques that maximize the use of observable inputs. Assets and liabilities are classified in their entirety based on the lowest priority level of input that is significant to the fair value measurement. Where observable inputs are available for substantially the full term of the asset or liability, the instrument is categorized in Level 2. If the inputs into the valuation are not corroborated by market data, in such instances, the valuation for these contracts is established using techniques including extrapolation from or interpolation between actively traded contracts as well as calculation of implied volatilities. When such inputs have a significant impact on the measurement of fair value, the instrument is categorized as Level 3. The Company regularly evaluates and validates the inputs used to determine fair value by using pricing services to support the underlying market price of commodity, interest rates and foreign currency exchange rates.

	The Company uses a discounted valuation technique to fair value its derivative assets and liabilities. The primary inputs in the valuation models for commodity contracts are market observable forward commodity curves and risk-free discount rates and to a lesser degree credit spreads.

	The primary inputs into the valuation of interest rate swaps and foreign currency contracts are forward interest rates, foreign currency exchange rates, and to a lesser degree, credit spreads.

	The Company's interest rate swaps, foreign currency contracts, and commodity contracts are considered Level 2, since all significant inputs are corroborated by market observable data. There were no transfers in or out of Level 1, Level 2 and Level 3 during the period.

Stockholders_Equity

Stockholder's Equity	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Stockholder's Equity	STOCKHOLDER'S EQUITY

	Follow-on Public Offering

	On January 22, 2015, the Company sold 13,800,000 shares of its Class A common stock to the public in a registered offering, including 1,800,000 shares sold pursuant to the underwriters' overallotment option. The Company received net proceeds of $390.6 million, $50.9 million of which was used to repurchase Class B common stock and Class B units from SunEdison and the remainder was used to acquire 13,800,000 Class A units of Terra LLC. Terra LLC used the proceeds from the sale of its Class A units to pay, among other things, for part of the purchase price of the First Wind acquisition and to repay remaining amounts outstanding under the Term Loan.

	As of March 31, 2015, the following shares of the Company were outstanding:


	Shares:	Number Outstanding	Shareholder(s)
	Class A common stock	55,951,690	*

	Class B common stock	62,726,654	SunEdison

	Class B1 common stock	5,840,000	Riverstone

	Total Shares	124,518,344

	———
	* Class A common stockholders are comprised of: public and private investors, executive officers, management and personnel who provide services to the Company. The par value of Class A common stock reflected on the unaudited consolidated balance sheets and unaudited consolidated statement of stockholders' equity excludes 2,445,464 shares of unvested restricted Class A common stock awards.

	As of March 31, 2015, the Company owned 44.9% of Terra LLC and consolidated the results of Terra LLC through its controlling interest, with SunEdison's 50.4% interest and Riverstone's 4.7% interest shown as non-controlling interests.

	Dividends

	On December 22, 2014, the Company declared a quarterly dividend for the fourth quarter on the Company's Class A common stock of $0.27 per share, or $1.08 per share on an annualized basis. The fourth-quarter dividend was paid on March 16, 2015 to shareholders of record as of March 2, 2015.

Stockbased_Compensation

Stock-based Compensation	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based Compensation	STOCK-BASED COMPENSATION

	The Company has equity incentive plans that provide for the award of incentive and nonqualified stock options, restricted stock awards ("RSAs") and restricted stock units ("RSUs") to personnel and directors who provide services to the Company, including personnel and directors who provide services to SunEdison. As of March 31, 2015, an aggregate of 1,696,198 shares of Class A common stock were available for issuance under these plans. The stock-based compensation expense related to issued stock options, RSAs, and RSUs is recorded as a component of general and administrative expenses in the Company’s unaudited consolidated statements of operations and totaled $5.1 million for the three months ended March 31, 2015. Upon exercise of the RSAs, RSUs, or stock options, the Company will issue shares that have been previously authorized to be issued.

	Restricted Stock Awards

	The following table presents information regarding outstanding RSAs as of March 31, 2015, and changes during the three months ended March 31, 2015:


		Number of RSAs Outstanding		Weighted Average Grant Date Fair Value Per Share
	Balance at January 1, 2015	4,876,567		$	1.12

	Granted	—		—

	Forfeited	(132,588	)	0.68

	Modified	66,294		35.05

	Balance at March 31, 2015	4,810,273		$	1.6


	On March 20, 2015, the Company modified an award of a former person who provided services to the Company, which resulted in the forfeiture of the existing award and granting of a new award.

	The amount of stock compensation expense related to the RSAs during the three months ended March 31, 2015 was $2.5 million. As of March 31, 2015, $1.1 million of total unrecognized compensation cost related to these awards is expected to be recognized over a period of approximately two years.

	Restricted Stock Units

	The following table presents information regarding outstanding RSUs as of March 31, 2015, and changes during the three months ended March 31, 2015:


		Number of RSUs Outstanding		Weighted Average Grant Date Fair Value Per Share
	Balance at January 1, 2015	825,943		$	27.37

	Granted	1,104,200		34.01

	Balance at March 31, 2015	1,930,143		$	31.17


	The amount of stock compensation expense related to RSUs was $2.0 million during the three months ended March 31, 2015. As of March 31, 2015, $18.9 million of total unrecognized compensation cost related to RSUs is expected to be recognized over a period of approximately five years.

	On March 10, 2015, the Company awarded 53,700 RSUs to personnel who provide services to the Company. These awards are 80% performance-based and 20% time-based, which are vested at 25% per year over a four year period. For the performance-based RSUs, there are three performance tiers with each tier representing 33% of the performance-based tranche. The performance tiers are measured on the dividend per share of the Company. If certain performance goals are not achieved, the first, second and third performance tiers are forfeited in their entirety. If certain performance goals are met by the first quarter 2016, 2017 and 2018, as measured by the last twelve months, the first, second and third tier will vest at 50%, 75% or 100%. Upon achievement of targets, participants will vest in their respective tier at 50% during the measurement year, 30% the following year and 20% the year after that. The grant date fair value of these awards was $1.6 million, which will be recognized as compensation cost on a straight line basis over the requisite service periods of four years for the time-based awards and five years for the performance-based awards. The grant date fair value of these awards was calculated based on the Company's stock price as of the date of grant since meeting the requisite performance conditions was considered probable as of this date.

	During the three months ended March 31, 2015, the Company granted 960,200 RSUs with a weighted average grant date fair value of $34.23 to personnel who provide services to SunEdison. The amount of stock-based compensation expense related to these RSUs was $0.2 million for the three months ended March 31, 2015 and is recognized as a dividend to SunEdison on the unaudited consolidated balance sheets.

	During the three months ended March 31, 2015, SunEdison granted 107,200 RSUs to personnel who provide services to the Company. The amount of stock-based compensation expense related to these RSUs was inconsequential for the three months ended March 31, 2015 and is reflected in the unaudited consolidated statement of operations as part of general and administrative costs and has been treated as an equity contribution from SunEdison.

	Options

	The following table presents information regarding outstanding options as of March 31, 2015, and changes during the three months ended March 31, 2015:


		Number of Options Outstanding		Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value
						(in thousands)
	Balance at January 1, 2015	150,000		$	29.31

	Granted	—		—

	Balance at March 31, 2015	150,000		$	29.31	$	1,080

	Options exercisable at March 31, 2015	18,750		$	29.31	$	135


	Aggregate intrinsic value represents the value of the Company's closing stock price of $36.51 on the last trading date of the period in excess of the weighted-average exercise price multiplied by the number of options outstanding or exercisable.

The amount of stock compensation expense related to options was $0.2 million during the three months ended March 31, 2015. As of March 31, 2015, $1.0 million of total unrecognized compensation cost related to options is expected to be recognized ratably over a period of approximately four years.

Loss_Per_Share

Loss Per Share	3 Months Ended
	Mar. 31, 2015
Earnings Per Share [Abstract]
Loss Per Share	LOSS PER SHARE

	Basic earnings (loss) per share is computed by dividing net income (loss) by the number of weighted-average Class A common shares outstanding during the period. Diluted earnings (loss) per share is computed using the weighted-average Class A common shares outstanding and, if dilutive, potential Class A common shares outstanding during the period. Potential Class A common shares represent the incremental Class A common shares issuable for restricted stock units and stock option exercises. The Company calculates the dilutive effect of outstanding restricted stock units and stock options on earnings (loss) per share by application of the treasury stock method.

	Weighted Average Number of Shares


	Weighted average number of shares (in thousands):	Three Months Ended March 31, 2015
	Class A common stock - Basic and diluted	49,694


	Class A Common Stock

	Basic and diluted earnings (loss) per share for the three months ended March 31, 2015 was calculated as follows:


		Three Months Ended March 31, 2015
	(In thousands, except per share amounts)	Basic			Diluted (1)
	EPS Numerator:
	Net loss attributable to Class A Common stock shareholders	$	(28,116	)	$	(28,116	)
	EPS Denominator:
	Weighted-average shares outstanding	49,694			49,694

	Loss per share	$	(0.57	)	$	(0.57	)
	———
	(1) The computations for diluted earnings (loss) per share for the three months ended March 31, 2015 excludes approximately 62,726,654 shares of Class B common stock, 5,840,000 shares of Class B1 common stock, 2,445,464 of unvested RSAs, 1,930,143 RSUs and 150,000 options to purchase the Company's shares because the effect would have been anti-dilutive.

Noncontrolling_Interests

Non-controlling Interests	3 Months Ended
	Mar. 31, 2015
Noncontrolling Interest [Abstract]
Non-controlling Interests	15. NON-CONTROLLING INTERESTS

	Non-controlling Interest

	Non-controlling interests represent the portion of net assets in consolidated entities that are not owned by the Company. The following table presents the non-controlling interest balances by entity, reported in stockholders’ equity in the unaudited consolidated balance sheets as of March 31, 2015 and December 31, 2014:



	(in thousands)	31-Mar-15			31-Dec-14
	Non-controlling interests in Terra LLC (1):
	SunEdison	$	788,568		$	722,342

	Riverstone	73,418			65,376

	Total non-controlling interests in Terra LLC	861,986			787,718

	Total non-controlling interests in renewable energy facilities	290,628			256,811

	Total non-controlling interests	$	1,152,614		$	1,044,529

	———
	(1) Reflects an equity reallocation of $94.0 million due to a quarterly adjustment of capital balances to reflect respective ownership percentages as of the balance sheet date.

	Non-controlling interest buyout

	On March 31, 2015, the Company completed the buyout of a significant portion, approximately 92% of one of the partners’ tax equity ownership interest in our Kaheawa Wind Power facility. The value associated with the buyout was deemed to be the fair value of the non-controlling interest as of acquisition date. The cash paid for this buyout was $54.7 million.

	Redeemable non-controlling interests

	Non-controlling interests in subsidiaries that are redeemable either at the option of the holder or at fixed and determinable prices at certain dates are classified as redeemable non-controlling interests in subsidiaries between liabilities and stockholders' equity in the unaudited consolidated balance sheets. The redeemable non-controlling interests in subsidiaries balance is determined using the hypothetical liquidation at book value method for the VIE funds or allocation of share of income or losses in other subsidiaries subsequent to initial recognition, however, the non-controlling interests balance cannot be less than the estimated redemption value. The following table presents the activity of the redeemable non-controlling interest balance reported on the unaudited consolidated balance sheets as of as of March 31, 2015 and December 31, 2014:



		Redeemable Non-controlling Interests
		Capital			Accumulated Deficit			Total
	Balance at January 1, 2015	$	24,338		$	—		$	24,338

	Consolidation of redeemable non-controlling interests in acquired projects	1,348			—			1,348

	Sale of membership interests in projects	403			—			403

	Distributions	(716		)	—			(716		)

	Net loss	—			(169		)	(169		)

	Balance at March 31, 2015	$	25,373		$	(169	)	$	25,204

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
Commitments and Contingencies	Mar. 31, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES

	Letters of Credit

	The Company's customers, vendors and regulatory agencies often require the Company to post letters of credit in order to guarantee performance under relevant contracts and agreements. The Company is also required to post letters of credit to secure obligations under various swap agreements and leases and may, from time to time, decide to post letters of credit in lieu of cash deposits in reserve accounts under certain financing arrangements. The amount that can be drawn under some of these letters of credit may be increased from time to time subject to the satisfaction of certain conditions. As of March 31, 2015, the Company had outstanding letters of credit in the amount of $162.7 million.

	Guarantee Agreements

	The Company and its subsidiaries have provided guarantees to certain of its institutional tax equity investors in connection with its tax equity financing transactions. These guarantees do not guarantee the returns targeted by the tax equity investors, but rather support any potential indemnity payments payable under the tax equity agreements. The Company and its subsidiaries may also provide guarantees in connection with acquisitions of third party assets or to support contractual obligations.

	Membership Interest Purchase and Sale Agreement

	The Company entered into two Membership Interest Purchase and Sale Agreements ("MIPSA") with affiliates of SunEdison to purchase two wind facilities. See Note 17. Related Parties for additional discussion of these MIPSAs.

	Third Party Acquisitions

	The Company has committed to third party acquisitions as follow:

	Moose Power Acquisition

	On March 31, 2015, the Company entered into a sale and purchase agreement to acquire 13 solar rooftop and one ground mount facilities from Moose Power Inc. (the ‘‘Moose Power Acquisition’’). The facilities are located in Ontario, Canada and have a total nameplate capacity of 5.6 MW. The facilities are contracted under long-term PPAs with investment grade utilities with an average credit rating of Aa2, and the PPAs have a weighted average remaining life of approximately 19 years. The Company has completed the acquisition of three of the facilities, representing total nameplate capacity of 1.8 MW. The Company expects to complete the acquisition of seven of the projects by the end of the second quarter of 2015 and the final four projects in the fourth quarter of 2015, representing total nameplate capacity of 2.0 MW and 1.8 MW, respectively.

	Invenergy Acquisition

	On March 31, 2015, the Company entered into a sale and purchase agreement to acquire two utility scale, ground mounted solar facilities from Invenergy Solar LLC (the ‘‘Invenergy Acquisition’’ and, together with the Moose Power Acquisition, the "Canadian Acquisitions"). The facilities are located in Ontario, Canada and have a total nameplate capacity of 25.0 MW. The facilities are contracted under long-term PPAs with an investment grade utility with a credit rating of Aa2, and the PPAs have a weighted average remaining life of 18 years. The transaction is expected to close in the second quarter of 2015, subject to regulatory approvals and customary closing conditions.

	The Company anticipates that the aggregate consideration payable for the Canadian Acquisitions will be approximately CAD 164.1 million ($129.8 million USD equivalent), including CAD 69.7 million (55.1 million USD equivalent) of project level debt repayment.

	Legal Proceedings

	We are not a party to any legal proceedings other than legal proceedings arising in the ordinary course of our business. We are also a party to various administrative and regulatory proceedings that have arisen in the ordinary course of our business. Although we cannot predict with certainty the ultimate resolution of such proceedings or other claims asserted against us, we do not believe that any currently pending legal proceeding to which we are a party will have a material adverse effect on our business, financial condition or results of operations.

	Daniel Gerber v. Wiltshire Council

	On March 5, 2015, the U.K. High Court issued a verdict that quashed (nullified) the planning permission necessary to build the Company’s 11.2 MW Norrington renewable energy facility in Wiltshire, England. The court found that, among other issues, the local Wiltshire council failed to properly notify a local landowner (the claimant) or notify the English historic preservation agency before granting the permission. U.K. counsel have advised us that the quashing of this planning permission deviates significantly from established case law. The Company filed its appeal of this ruling on March 25, 2015 and plans to assert a vigorous defense. At this time, the Company does not have enough information regarding the probable outcome or the estimated range of reasonably probable losses associated with this ruling, and as of March 31, 2015, no such accrual has been recorded in the unaudited consolidated financial statements. The renewable energy facility was constructed by SunEdison pursuant to an engineering, procurement and construction agreement, under which SunEdison assumed development and construction risk. If the ultimate outcome of this case were unfavorable and no replacement permit could be obtained, the Company would therefore be able recover its investment in this project from SunEdison.

Related_Parties

Related Parties	3 Months Ended
	Mar. 31, 2015
Related Party Transactions [Abstract]
Related Parties	RELATED PARTIES

	Management Services Agreement

	General and administrative affiliate costs represent costs incurred by SunEdison for services provided to the Company pursuant to the Management Services Agreement. Pursuant to the Management Services Agreement, SunEdison agreed to provide or arrange for other service providers to provide management and administrative services including legal, accounting, tax, treasury, project finance, information technology, insurance, employee benefit costs, communications, human resources, and procurement to the Company and its subsidiaries. As consideration for the services provided, the Company will pay SunEdison a base management fee as follows: (i) 2.5% of the Company's cash available for distribution in 2015, 2016, and 2017 (not to exceed $4.0 million in 2015, $7.0 million in 2016 or $9.0 million in 2017), and (ii) an amount equal to SunEdison's or other service provider's actual cost in 2018 and thereafter. General and administrative affiliate costs were $6.0 and $1.6 million during the three months ended March 31, 2015 and 2014, respectively.

	Cash consideration paid to SunEdison for these services for the three months ended March 31, 2015 totaled $0.7 million. Total actual costs for these services during the three months ended March 31, 2015 of $6.9 million is reflected in the unaudited consolidated statement of operations as general and administrative - affiliate costs and amounts in excess of cash consideration paid have been treated as an equity contribution from SunEdison.

	Interest Payment Agreement

	Immediately prior to the completion of the IPO on July 23, 2014, Terra LLC and Terra Operating LLC entered into an interest payment agreement (the "Interest Payment Agreement") with SunEdison and its wholly owned subsidiary, SunEdison Holdings Corporation, pursuant to which SunEdison will pay all of the scheduled interest on the Term Loan through the third anniversary of Terra LLC and Terra Operating LLC entering into the Term Loan, up to an aggregate of $48.0 million over such period (plus any interest due on any payment not remitted when due). Interest expense incurred under the term loan is reflected in the unaudited consolidated statement of operations and the reimbursement for such costs is treated as an equity contribution in additional paid-in capital from SunEdison. During the three months ended March 31, 2015, the Company received $4.0 million equity contribution from SunEdison pursuant to the Interest Payment Agreement. There were no amounts outstanding as of March 31, 2015.

	On January 28, 2015, Terra LLC and Terra Operating entered into the Amended and Restated Interest Payment Agreement (the “Amended Interest Payment Agreement”) with SunEdison and SunEdison Holdings Corporation. The Amended Interest Payment Agreement amends and restates the Interest Payment Agreement, all in accordance with the terms of the Intercompany Agreement. Under the Amended Interest Payment Agreement, SunEdison agreed to provide support with respect to the interest payment obligations of Terra Operating LLC with respect to its $800.0 million aggregate principal amount of 5.875% Senior Notes due 2023 under the Indenture, dated January 28, 2015.

	Incentive Revenue

	Certain solar renewable energy certificates ("SRECs") are sold to SunEdison under contractual arrangements at fixed prices. Revenue from the sale of SRECs to affiliates was $0.2 million and $0.1 million during the three months ended March 31, 2015 and 2014, respectively, and are reported as operating revenues, net in the unaudited consolidated statements of operations.

	Operations and Maintenance

	Operations and maintenance services are provided to the Company by affiliates of SunEdison pursuant to contractual agreements. Costs incurred for these services were $3.6 million and $0.4 for the three months ended March 31, 2015 and 2014, respectively, and are reported as cost of operations - affiliates in the unaudited consolidated statements of operations.

	SunEdison and Affiliates

	Certain of the Company's expenses and capital expenditures related to construction in process are paid by affiliates of SunEdison and are reimbursed by the Company to the same, or other affiliates of SunEdison. Additionally, all amounts incurred by the Company and not paid as of the balance sheet date for Call Right Projects acquired from SunEdison are reported as due to SunEdison and affiliates.

	As of March 31, 2015, SunEdison and affiliates owed the Company $18.2 million, which is reported as due from SunEdison and affiliates, net in the unaudited consolidated balance sheets. As of December 31, 2014, the Company owed SunEdison and affiliates $153.1 million, which is reported as due to SunEdison and affiliates, net in the unaudited consolidated balance sheets.

	Incentive Distribution Rights

	Incentive Distribution Rights ("IDRs") represent the right to receive increasing percentages (15.0%, 25.0% and 50.0%) of Terra LLC’s quarterly distributions after the Class A Units, Class B units, and Class B1 units of Terra LLC have received quarterly distributions in an amount equal to $0.2257 per unit (the "Minimum Quarterly Distribution") and the target distribution levels have been achieved. Upon the completion of the IPO, SunEdison holds 100% of the IDRs.

	Initial IDR Structure

	If for any quarter:

	•	Terra LLC has made cash distributions to the holders of its Class A units, Class B1 units and, subject to the Distribution Forbearance Provisions, Class B units in an amount equal to the Minimum Quarterly Distribution; and

	•	Terra LLC has distributed cash to holders of Class A units and holders of Class B1 units in an amount necessary to eliminate any arrearages in payment of the Minimum Quarterly Distribution;

	then Terra LLC will make additional cash distributions for that quarter among holders of its Class A units, Class B units, Class B1 units and the IDRs in the following manner:

	•	first, to all holders of Class A units, Class B1 units and, subject to the Distribution Forbearance Provisions, Class B units, pro rata, until each holder receives a total of $0.3386 per unit for that quarter (the “First Target Distribution”) (150.0% of the Minimum Quarterly Distribution);

	•	second, 85.0% to all holders of Class A units, Class B1 units and, subject to the Distribution Forbearance Provisions, Class B units, pro rata, and 15.0% to the holders of the IDRs, until each holder of Class A units, Class B1 units and, subject to the Distribution Forbearance Provisions, Class B units receives a total of $0.3950 per unit for that quarter (the “Second Target Distribution”) (175.0% of the Minimum Quarterly Distribution);

	•	third, 75.0% to all holders of Class A units, Class B1 units and, subject to the Distribution Forbearance Provisions, Class B units, pro rata, and 25.0% to the holders of the IDRs, until each holder of Class A units, Class B1 units and, subject to the Distribution Forbearance Provisions, Class B units receives a total of $0.4514 per unit for that quarter (the “Third Target Distribution”) (200.0% of the Minimum Quarterly Distribution); and

	•	thereafter, 50.0% to all holders of Class A units, Class B1 units and, subject to the Distribution Forbearance Provisions, Class B units, pro rata, and 50.0% to the holders of the IDRs.

	There were no IDR payments made by the Company during the three months ended March 31, 2015.

	Membership Interest Purchase and Sale Agreement

	On March 30, 2015, the Company entered into two MIPSAs in which the Company has committed to purchase two wind facilities from affiliates of SunEdison upon the facilities achieving commercial operations. The facilities are located in Maine and Texas with nameplate capacities of 147.6 MW and 200.0 MW, respectively. The total fixed purchase price is $378.2 million subject to certain adjustments. The facilities are currently under construction with commercial operations expected to be achieved in the fourth quarter of 2015.

	Support Agreement

	The Company entered into a project support agreement with SunEdison (the "Support Agreement"), which provides us the option to purchase additional solar projects from SunEdison in 2015 and 2016. The Support Agreement also provides us a right of first offer with respect to certain other projects.

	On January 9, 2015, the Company paid $18 million to SunEdison as a deposit for the future acquisition of a 69 MW Call Right Project under the Support Agreement. This solar facility is located in Chile and is expected to achieve commercial operations and to be acquired by the Company in the fourth quarter of 2015. This deposit has been recored as due from SunEdison and affiliates in the unaudited consolidated balance sheet.

	Subsequent Event

On April 27, 2015, the Company paid $10 million to SunEdison as a deposit for the future acquisition of a 10 MW Call Right Project under the Support Agreement. This solar facility is located in England and achieved commercial operations during the first quarter of 2015. The Company expects to acquire this facility in the second quarter of 2015.

Segment_Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Segment Reporting	SEGMENT REPORTING

	The Company has two reportable segments, Solar and Wind, that include our entire portfolio of renewable energy facility assets, determined based on the “management” approach. Prior to the acquisition of First Wind, the Company had one reportable segment, Solar. This approach designates the internal reporting used by management for making decisions and assessing performance as the source of the reportable segments. Corporate expenses include general and administrative expenses, acquisition costs, formation and offering related fees and expenses, interest expense on corporate indebtedness and stock-based compensation. All net operating revenues for the three months ended March 31, 2015 were earned by our reportable segments from external customers in the United States and its unincorporated territories, Canada, the United Kingdom and Chile. All net operating revenues for the three months ended March 31, 2014 were earned from external customers in the United States and its unincorporated territories and Chile.

	The following table reflects summarized financial information concerning the Company’s reportable segments for the three months ended March 31, 2015 and 2014:



		Three Months Ended												Three Months Ended
		March 31, 2015												March 31, 2014
	(In thousands)	Solar			Wind (1)			Corporate			Total			Solar		Wind		Corporate			Total
	Operating revenues, net	$	48,370		$	22,145		$	—		$	70,515		$	11,880	$	—	$	—		$	11,880

	Depreciation, accretion and amortization	25,755			6,136			—			31,891			3,241		—		—			3,241

	Other operating costs and expenses	15,007			13,013			22,567			50,587			910		—		1,590			2,500

	Interest expense, net	16,338			757			19,760			36,855			6,555		—		527			7,082

	Other non-operating expenses	426			8,435			26,026			34,887			595		—		—			595

	Income tax benefit (2)	—			—			(45		)	(45		)	—		—		(457		)	(457		)

	Net loss	$	(9,156	)	$	(6,196	)	$	(68,308	)	$	(83,660	)	$	579	$	—	$	(1,660	)	$	(1,081	)

	Balance Sheet
	Total assets (3)	$	3,198,075		$	995,889		$	171,654		$	4,365,618		$	3,072,250	$	—	$	514,170		$	3,586,420

	———
	(1) Represents the operating results of our wind facilities from January 29, 2015, the date of the acquisition of the First Wind operating portfolio, to March 31, 2015.
	(2) Income tax benefit is not allocated to the Company's Solar and Wind segments.
	(3) Represents total assets as of March 31, 2015 and December 31, 2014. Corporate assets include cash and cash equivalents; other current assets; corporate-level debt and related deferred financing costs, net and other assets.

Other_Comprehensive_Income_Los

Other Comprehensive Income (Loss)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Other Comprehensive Income (Loss)	OTHER COMPREHENSIVE INCOME (LOSS)

	Comprehensive income (loss) represents a measure of all changes in equity that result from recognized transactions and other economic events other than transactions with owners in their capacity as owners. Other comprehensive income (loss) includes foreign currency translations and gains (losses) on hedging instruments. There was no comprehensive income (loss) for the three months ended March 31, 2015.

	The following table presents the changes in each component of accumulated other comprehensive loss, net of tax:


	(In thousands)	Foreign Currency Translation Adjustments			Hedging Activities			Accumulated Other Comprehensive Loss
	Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, December 31, 2014	$	(1,149	)	$	(488	)	$	(1,637	)
	Net unrealized losses arising during the period	(3,275		)	(2,248		)	(5,523		)
	Reclassification of net losses to net income:
	Interest expense, net	—			2,857			2,857

	Other comprehensive (loss) income	$	(3,275	)	$	609		$	(2,666	)

	Accumulated other comprehensive (loss) income	(4,424		)	121			(4,303		)

	Other comprehensive (loss) income attributable to non-controlling interests	(1,862		)	168			(1,694		)

	Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, March 31, 2015	$	(2,562	)	$	(47	)	$	(2,609	)

	The following table presents each component of other comprehensive loss and the related tax effects for the three months ended March 31, 2015:


	(In thousands)	Before Tax			Tax Effect			Net of Tax
	Foreign currency translation adjustments:
	Net unrealized losses arising during the period	$	(3,275	)	$	—		$	(3,275	)

	Hedging activities:
	Net unrealized losses arising during the period	(2,248		)	—			(2,248		)

	Reclassification of net losses into earnings	2,857			—			2,857

	Net change	609			—			609

	Other comprehensive loss	$	(2,666	)	$	—		$	(2,666	)

	Less: other comprehensive loss attributable to non-controlling interests, net of tax							(1,694		)
	Other comprehensive loss attributable to TerraForm Power, Inc. Class A stockholders							$	(972	)

Nature_of_Operations_Policies

Nature of Operations (Policies)	3 Months Ended
Nature of Operations (Policies)	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	In the opinion of management, the accompanying unaudited consolidated financial statements contain all material adjustments consisting of normal and recurring accruals necessary to present fairly the Company's unaudited consolidated financial position as of March 31, 2015, and the results of operations, comprehensive income and cash flows for the three months ended March 31, 2015, and 2014.
Use of Estimates	Use of Estimates

	In preparing the unaudited consolidated financial statements, the Company used estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements. Such estimates also affect the reported amounts of revenues, expenses and cash flows during the reporting period. Actual results may differ from estimates under different assumptions or conditions.
New Accounting Pronouncement	Recent Accounting Pronouncements

	In May 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-09, Revenue from Contracts with Customers, which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. This ASU will replace most existing revenue recognition guidance in U.S. GAAP when it becomes effective. This standard will become effective for us on January 1, 2018. Early application is permitted but not before January 1, 2017. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is currently evaluating the effect that ASU No. 2014-09 will have on its consolidated financial statements and related disclosures. The Company has not yet selected a transition method or determined the effect of the standard on its ongoing financial reporting.

	In February 2015, the FASB issued ASU No. 2015-02 Consolidation (Topic 810) Amendments to the Consolidation Analysis, which affects the following areas of the consolidation analysis: limited partnerships and similar entities, evaluation of fees paid to a decision maker or service provider as a variable interest and in determination of the primary beneficiary, effect of related parties on the primary beneficiary determination and for certain investment funds. ASU No. 2015-02 is effective for us for our fiscal year ending December 31, 2016 and interim periods therein. We are evaluating the impact of this standard on our consolidated statements of financial position, results of operations and cash flows.

	In April 2015, the FASB issued ASU No. 2015-03 Interest - Imputation of Interest (Subtopic 835-30) Simplifying the Presentation of Debt Issuance Costs, which requires debt issuance costs related to a recognized debt liability to be presented on the balance sheet as a direct deduction from the debt liability. ASU No. 2015-03 is effective for us for our fiscal year ending December 31, 2016 and interim periods therein. We are evaluating the impact of this standard on our consolidated balance sheet.
Earnings Per Share	Basic earnings (loss) per share is computed by dividing net income (loss) by the number of weighted-average Class A common shares outstanding during the period. Diluted earnings (loss) per share is computed using the weighted-average Class A common shares outstanding and, if dilutive, potential Class A common shares outstanding during the period. Potential Class A common shares represent the incremental Class A common shares issuable for restricted stock units and stock option exercises. The Company calculates the dilutive effect of outstanding restricted stock units and stock options on earnings (loss) per share by application of the treasury stock method.
Segment Reporting, Policy	The Company has two reportable segments, Solar and Wind, that include our entire portfolio of renewable energy facility assets, determined based on the “management” approach. Prior to the acquisition of First Wind, the Company had one reportable segment, Solar. This approach designates the internal reporting used by management for making decisions and assessing performance as the source of the reportable segments. Corporate expenses include general and administrative expenses, acquisition costs, formation and offering related fees and expenses, interest expense on corporate indebtedness and stock-based compensation. All net operating revenues for the three months ended March 31, 2015 were earned by our reportable segments from external customers in the United States and its unincorporated territories, Canada, the United Kingdom and Chile.

Transactions_Between_Entities_1

Transactions Between Entities Under Common Control (Tables)	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Recast of Prior Financial Information	The following table presents the changes to previously reported amounts of the Company's consolidated balance sheet as of December 31, 2014 included in the Company's Annual Report on Form 10-K:


	(In thousands)	December 31, 2014 As Reported			Acquired Call Rights Projects			December 31, 2014 Recast
	Balance Sheet Caption
	Cash and cash equivalents	$	468,393		$	161		$	468,554

	Due from SunEdison and affiliates, net	19,640			(19,640		)	—

	Prepaid expenses and other current assets	21,840			780			22,620

	Property and equipment, net	2,327,803			227,101			2,554,904

	Change in total assets				$	208,402


	Current portion of long-term debt	$	80,133		$	3,971		$	84,104

	Accounts payable, accrued expenses and other current liabilities	81,781			824			82,605

	Due to SunEdison and affiliates, net	—			153,052			153,052

	Long-term debt and financing lease obligations, less current portion	1,517,962			50,555			1,568,517

	Change in total liabilities				$	208,402


	The following table presents the changes to previously reported amounts of the Company's consolidated statement of cash flows for the year ended December 31, 2014, included in the Company's Annual Report on Form 10-K:


	(In thousands)	December 31, 2014 As Reported			Acquired Call Rights Projects			December 31, 2014 Recast
	Cash Flows Caption
	Changes in assets and liabilities:
	VAT receivable, prepaid expenses and other current assets	$	23,730		$	(819	)	$	22,911

	Accounts payable, accrued interest, and other current liabilities	3,371			865			4,236

	Cash flows from investing activities:
	Cash paid to SunEdison and third parties for solar generation facility construction	(816,682		)	(236,189		)	(1,052,871		)
	Deposit for acquisition of Call Right Projects	(34,000		)	34,000			—

	Cash flows from financing activities:
	Borrowings of long-term debt	399,806			62,111			461,917

	Principal payments on long-term debt	(341,336		)	1,766			(339,570		)

	Net increase in cash and cash equivalents	467,513			427			467,940

	Effect of exchange rate changes on cash and cash equivalents	(164		)	(266		)	(430		)
	Cash and cash equivalents at end of period	468,393			161			468,554

Acquisitions_Tables

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2015
Business Combinations [Abstract]
Business Acquisition, Pro Forma Information	The 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 acquisitions been consummated on the date assumed or of the Company’s results of operations for any future date.


		Three Months Ended March 31,
	(In thousands, unaudited)	2015			2014
	Total operating revenues, net	$	39,851		$	58,281

	Net loss	6,987			21,987

Schedule of Allocation of Assets and Liabilities of Purchased Solar Generation Facilities	The estimated fair values of assets, liabilities and non-controlling interests as of March 31, 2015, are as follows:


		2015 Preliminary			2014 Preliminary						2014 Final		Total Allocation
	(In thousands)	First Wind			Mt. Signal		Capital Dynamics		Other		Other
	Property and equipment	$	803,103		$	649,005	$	216,771	$	102,788	$	150,934	$	1,922,601

	Accounts receivable	9,378			11,617		2,309		7,100		2,380		32,784

	Restricted cash	6,630			22,165		15		5,564		9,156		43,530

	Deferred income taxes	—			—		21,118		—		—		21,118

	Other assets	68,671			12,621		1,490		1,455		3,896		88,133

	Intangible assets	125,671			117,925		71,859		21,656		105,361		442,472

	Total assets acquired	1,013,453			813,333		313,562		138,563		271,727		2,550,638

	Long-term debt	59,816			413,464		—		65,084		72,930		611,294

	Accounts payable, accrued expenses and other current liabilities	9,934			24,813		1,194		3,499		1,286		40,726

	Asset retirement obligations	12,403			4,656		13,073		6,622		10,752		47,506

	Deferred income taxes	—			—		25,191		990		—		26,181

	Total liabilities assumed	82,153			442,933		39,458		76,195		84,968		725,707

	Non-controlling interest	120,864			78,745		16,600		2,850		1,400		220,459

	Purchase price, net of cash acquired	$	810,436		$	291,655	$	257,504	$	59,518	$	185,359	$	1,604,472

Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following table is a summary of assets and liabilities acquired from SunEdison in connection with these Call Right Projects:


	(in thousands)		As of March 31, 2015
	Current assets		$	19,424

	Property, plant and equipment		274,685

	Non-current assets		24,912

	Total assets acquired		319,021

	Long-term debt		174,467

	Other liabilities		71,592

	Total liabilities assumed		246,059

	Net assets acquired		$	72,962

	Cash Paid		$	89,621

	Adjustments to equity reflected as distribution to non-controlling interests		16,659

Property_and_Equipment_Tables

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2015
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property and equipment, net consists of the following:


		March 31, 2015			December 31, 2014
	(In thousands)
	Renewable energy facilities	$	3,404,264		$	2,220,401

	Less accumulated depreciation - renewable energy facilities	(74,957		)	(50,080		)
	Property and equipment, net	3,329,307			2,170,321

	Construction in progress - renewable energy facilities	100,323			384,583

	Total property and equipment	$	3,429,630		$	2,554,904

Intangible_Assets_Tables

Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Gross Carrying Amount and Accumulated Amortization of Other Intangible Asses	The following table presents the gross carrying amount and accumulated amortization of intangible assets as of March 31, 2015:


	(In thousands, except weighted average amortization period)	Weighted Average Amortization Period	Gross Carrying Amount		Accumulated Amortization			Accumulated Currency Translation Adjustment			Net Book Value
	Energy revenue contracts	20 years	$	463,636	$	(5,329	)	$	(3,379	)	$	454,928


	The following table presents the gross carrying amount and accumulated amortization of intangible assets as of December 31, 2014:


	(In thousands, except weighted average amortization period)	Weighted Average Amortization Period	Gross Carrying Amount		Accumulated Amortization			Accumulated Currency Translation Adjustment			Net Book Value
	Energy revenue contracts	21 years	$	371,765	$	(6,169	)	$	(3,923	)	$	361,673

Variable_Interest_Entities_Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities	The carrying amounts and classification of the consolidated VIEs’ assets and liabilities included in the Company's unaudited consolidated balance sheet are as follows:


	(In thousands)	March 31, 2015		December 31, 2014
	Current assets	$	64,973	$	69,955

	Noncurrent assets	1,803,709		1,756,276

	Total assets	$	1,868,682	$	1,826,231

	Current liabilities	$	57,898	$	64,324

	Noncurrent liabilities	729,644		707,989

	Total liabilities	$	787,542	$	772,313

Longterm_Debt_Tables

Long-term Debt (Tables)	3 Months Ended
	Mar. 31, 2015
Debt Disclosure [Abstract]
Schedule of Debt	Long-term debt consists of the following:


	(in thousands, except rates)		March 31, 2015				December 31, 2014				Interest Type	Current Interest Rate %		Financing Type

	Description:
	Corporate-level long-term debt:
	Term Loan, due 2019		$	—			$	573,500			Variable	5.3 (1)		Term debt

	Senior Notes, due 2023		800,000				—				Fixed	5.9		Senior notes

	Revolver		150,000				—				Variable	2.7		Revolving loan

	Project-level long-term debt:
	Permanent financing		882,865				886,149				-2	6.1 (3)		Term debt / Senior notes

	Construction financing		212,072				97,518				Variable	2.9 (3)		Construction debt

	Financing lease obligations		154,716				93,981				Imputed	5.1 (3)		Financing lease obligations

	Total Principal long-term debt and financing lease obligations		$	2,199,653			$	1,651,148				5.9 (3)

	Less current maturities		(229,517		)		(84,104		)
	Net unamortized (discount) premium		(4,975		)		1,473

	Long-term debt and financing lease obligations, less current portion		$	1,965,161			$	1,568,517

	———
	(1) The Company entered into an interest rate swap agreement (see Note 10. Derivatives) fixing the interest rate at 5.33%, which was terminated upon repayment of the Term Loan.
	(2) Includes debt at variable or fixed interest rates. As of March 31, 2015, 38% of this balance had a variable interest rate and 62% of this balance had a fixed interest rate.
	(3) Represents the weighted average effective interest rate as of March 31, 2015.
Schedule of Maturities of Long-term Debt	The aggregate amounts of payments on long-term debt including financing lease obligations, and excluding amortization of debt discounts, due after March 31, 2015 are as follows:


	(In thousands)	Remainder of 2015 (1)				2016 (2)				2017			2018		2019		Thereafter		Total
	Maturities of long-term debt as of March 31, 2015	$	227,879			$	264,521			$	37,902		$	39,337	$	50,104	$	1,579,910	$	2,199,653

	———
	(1) The amount of long-term debt due in 2015 includes CAD 47.8 million (USD $37.8 million) of construction debt for SunE Perpetual Lindsay, which will be repaid by SunEdison in the third quarter of 2015 and an outstanding balance of $150.0 million on our Revolver.
	(2) The amount of long-term debt due in 2016 includes GBP 152.5 million (USD $225.6 million) of debt for the Fairwinds & Crundale facilities and the U.K. Call Right Projects.

Income_Taxes_Tables

Income Taxes (Tables)	3 Months Ended
Income Taxes (Tables)	Mar. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation	The income tax provision consisted of the following:


		Three Months Ended March 31,
	(In thousands, except effective tax rate)	2015			2014
	Loss before income tax benefit	$	(83,705	)	$	(1,538	)
	Income tax benefit	(45		)	(457		)
	Effective tax rate	0.1		%	29.7		%

Derivatives_Tables

Derivatives (Tables)	3 Months Ended
	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value	As of March 31, 2015 and December 31, 2014, fair values of the following derivative instruments were included in the line items indicated.


		Fair Value of Derivative Instruments
		Hedging Contracts				Derivatives Not Designated as Hedges
	(In thousands)	Interest Rate Swaps				Interest Rate Swaps				Foreign Currency Contracts			Commodity Contracts		Gross Amounts of Assets/Liabilities Recognized			Gross Amounts Offset in Consolidated Balance Sheet			Net Amounts in Consolidated Balance Sheet
	As of March 31, 2015
	Prepaid expenses and other current assets	$	—			$	—			$	2,669		$	8,482	$	11,151		$	(1,155	)	$	9,996

	Other assets	—				—				1,861			31,970		33,831			(781		)	33,050

	Total assets	$	—			$	—			$	4,530		$	40,452	$	44,982		$	(1,936	)	$	43,046

	Accounts payable and other current liabilities	$	845			$	—			$	—		$	—	$	845		$	—		$	845

	Other long-term liabilities	470				1,381				3,711			—		5,562			(1,936		)	3,626

	Total liabilities	$	1,315			$	1,381			$	3,711		$	—	$	6,407		$	(1,936	)	$	4,471


	As of December 31, 2014
	Prepaid expenses and other current assets	$	—			$	—			$	—		$	—	$	—		$	—		$	—

	Other assets	—				—				1,811			—		1,811			—			1,811

	Total assets	$	—			$	—			$	1,811		$	—	$	1,811		$	—		$	1,811

	Accounts payable and other current liabilities	$	1,925			$	1,279			$	685		$	—	$	3,889		$	—		$	3,889

	Other long-term liabilities	—				—				—			—		—			—			—

	Total liabilities	$	1,925			$	1,279			$	685		$	—	$	3,889		$	—		$	3,889

Schedule of Notional Amounts of Outstanding Derivative Positions	As of March 31, 2015 and December 31, 2014, notional amounts for derivative instruments consisted of the following:


		Notional Amount as of
	(In thousands)	March 31, 2015				December 31, 2014
	Derivatives designated as hedges:
	Interest rate swaps (USD)	$	50,150			$	349,213

	Derivatives not designated as hedges:
	Interest rate swaps (USD)	16,857				16,861

	Foreign currency contracts (GBP)	56,348				58,710

	Foreign currency contracts (CAD)	25,097				25,415

	Commodity contracts (MWhs)	2,248				—

Gain (loss) of Derivative Instruments	Gains and losses on derivatives not designated as hedges for the three months ended March 31, 2015 and 2014 consisted of the following:


				Three Months Ended March 31,
	(In thousands)	Location of Loss Recognized in Income		2015				2014
	Interest rate swaps	Interest expense, net		$	236			$	—

	Foreign currency contracts	Loss on foreign currency exchange, net		97				—

	Commodity contracts	Operating revenues, net		4,259				—

Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]	Losses recognized related to interest rate swaps designated as cash flow hedges for the three months ended March 31, 2015 and 2014 consisted of the following:


		Three Months Ended March 31,
		Loss Recognized in Other Comprehensive Income (Effective Portion)							Location of Loss Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)		Amount of Loss Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)				Amount of Loss Recognized in Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)
	(In thousands)	2015			2014						2015		2014		2015		2014
	Interest rate swaps	$	2,248		$	—			Interest expense, net		$	2,857	$	—	$	—	$	—

Fair_Value_of_Financial_Instru1

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Disclosures [Abstract]
Carrying Amount and Estimated Fair Value of Terra LLC Long-term Debt	The carrying amount and estimated fair value of the Company's long-term debt as of March 31, 2015 and December 31, 2014 is as follows:



			As of March 31, 2015						As of December 31, 2014
	(In thousands)		Carrying Amount			Fair Value			Carrying Amount			Fair Value
	Long-term debt, including current portion		$	2,194,678		$	2,249,970		$	1,652,621		$	1,659,883

Fair Value, Assets and Liabilities Measured on 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 accompanying unaudited consolidated balance sheet:



	(In thousands)	As of March 31, 2015												As of December 31, 2014
	Assets	Level 1			Level 2			Level 3			Total			Level 1		Level 2		Level 3		Total
	Foreign currency contracts	$	—		$	2,594		$	—		$	2,594		$	—	$	1,811	$	—	$	1,811

	Commodity contracts	—			$	40,452		$	—		40,452			—		—		—		—

	Total derivative assets	$	—		$	43,046		$	—		$	43,046		$	—	$	1,811	$	—	$	1,811

	Liabilities
	Interest rate swaps	$	—		$	2,696		$	—		$	2,696		$	—	$	3,204	$	—	$	3,204

	Foreign currency contracts	—			1,775			—			1,775			—		685		—		685

	Total derivative liabilities	$	—		$	4,471		$	—		$	4,471		$	—	$	3,889	$	—	$	3,889

Stockholders_Equity_Tables

Stockholder's Equity (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Schedule of Stockholders Equity	As of March 31, 2015, the following shares of the Company were outstanding:


	Shares:	Number Outstanding	Shareholder(s)
	Class A common stock	55,951,690	*

	Class B common stock	62,726,654	SunEdison

	Class B1 common stock	5,840,000	Riverstone

	Total Shares	124,518,344

Stockbased_Compensation_Tables

Stock-based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	The following table presents information regarding outstanding RSAs as of March 31, 2015, and changes during the three months ended March 31, 2015:


		Number of RSAs Outstanding		Weighted Average Grant Date Fair Value Per Share
	Balance at January 1, 2015	4,876,567		$	1.12

	Granted	—		—

	Forfeited	(132,588	)	0.68

	Modified	66,294		35.05

	Balance at March 31, 2015	4,810,273		$	1.6

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	The following table presents information regarding outstanding RSUs as of March 31, 2015, and changes during the three months ended March 31, 2015:


		Number of RSUs Outstanding		Weighted Average Grant Date Fair Value Per Share
	Balance at January 1, 2015	825,943		$	27.37

	Granted	1,104,200		34.01

	Balance at March 31, 2015	1,930,143		$	31.17

Schedule of Share-based Compensation, Stock Options, Activity	The following table presents information regarding outstanding options as of March 31, 2015, and changes during the three months ended March 31, 2015:


		Number of Options Outstanding		Weighted Average Exercise Price Per Share		Aggregate Intrinsic Value
						(in thousands)
	Balance at January 1, 2015	150,000		$	29.31

	Granted	—		—

	Balance at March 31, 2015	150,000		$	29.31	$	1,080

	Options exercisable at March 31, 2015	18,750		$	29.31	$	135

Loss_Per_Share_Tables

Loss Per Share (Tables)	3 Months Ended
Loss Per Share (Tables)	Mar. 31, 2015
Earnings Per Share [Abstract]
Schedule of Weighted Average Number of Shares	Weighted Average Number of Shares


	Weighted average number of shares (in thousands):	Three Months Ended March 31, 2015
	Class A common stock - Basic and diluted	49,694
	Class A common stock - Basic and diluted	49,694
Schedule of Earnings Per Share, Basic and Diluted	Basic and diluted earnings (loss) per share for the three months ended March 31, 2015 was calculated as follows:


		Three Months Ended March 31, 2015
	(In thousands, except per share amounts)	Basic			Diluted (1)
	EPS Numerator:
	Net loss attributable to Class A Common stock shareholders	$	(28,116	)	$	(28,116	)
	EPS Denominator:
	Weighted-average shares outstanding	49,694			49,694
	Weighted-average shares outstanding	49,694			49,694
	Loss per share	$	(0.57	)	$	(0.57	)
	———
	(1) The computations for diluted earnings (loss) per share for the three months ended March 31, 2015 excludes approximately 62,726,654 shares of Class B common stock, 5,840,000 shares of Class B1 common stock, 2,445,464 of unvested RSAs, 1,930,143 RSUs and 150,000 options to purchase the Company's shares because the effect would have been anti-dilutive.

Noncontrolling_Interests_Table

Non-controlling Interests (Tables)	3 Months Ended
	Mar. 31, 2015
Noncontrolling Interest [Abstract]
Schedule of Noncontrolling Interest	The following table presents the non-controlling interest balances by entity, reported in stockholders’ equity in the unaudited consolidated balance sheets as of March 31, 2015 and December 31, 2014:



	(in thousands)	31-Mar-15			31-Dec-14
	Non-controlling interests in Terra LLC (1):
	SunEdison	$	788,568		$	722,342

	Riverstone	73,418			65,376

	Total non-controlling interests in Terra LLC	861,986			787,718

	Total non-controlling interests in renewable energy facilities	290,628			256,811

	Total non-controlling interests	$	1,152,614		$	1,044,529

	———
	(1) Reflects an equity reallocation of $94.0 million due to a quarterly adjustment of capital balances to reflect respective ownership percentages as of the balance sheet date.
Redeemable Noncontrolling Interest	The following table presents the activity of the redeemable non-controlling interest balance reported on the unaudited consolidated balance sheets as of as of March 31, 2015 and December 31, 2014:



		Redeemable Non-controlling Interests
		Capital			Accumulated Deficit			Total
	Balance at January 1, 2015	$	24,338		$	—		$	24,338

	Consolidation of redeemable non-controlling interests in acquired projects	1,348			—			1,348

	Sale of membership interests in projects	403			—			403

	Distributions	(716		)	—			(716		)

	Net loss	—			(169		)	(169		)

	Balance at March 31, 2015	$	25,373		$	(169	)	$	25,204

Segment_Reporting_Tables

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment	The following table reflects summarized financial information concerning the Company’s reportable segments for the three months ended March 31, 2015 and 2014:



		Three Months Ended												Three Months Ended
		March 31, 2015												March 31, 2014
	(In thousands)	Solar			Wind (1)			Corporate			Total			Solar		Wind		Corporate			Total
	Operating revenues, net	$	48,370		$	22,145		$	—		$	70,515		$	11,880	$	—	$	—		$	11,880

	Depreciation, accretion and amortization	25,755			6,136			—			31,891			3,241		—		—			3,241

	Other operating costs and expenses	15,007			13,013			22,567			50,587			910		—		1,590			2,500

	Interest expense, net	16,338			757			19,760			36,855			6,555		—		527			7,082

	Other non-operating expenses	426			8,435			26,026			34,887			595		—		—			595

	Income tax benefit (2)	—			—			(45		)	(45		)	—		—		(457		)	(457		)

	Net loss	$	(9,156	)	$	(6,196	)	$	(68,308	)	$	(83,660	)	$	579	$	—	$	(1,660	)	$	(1,081	)

	Balance Sheet
	Total assets (3)	$	3,198,075		$	995,889		$	171,654		$	4,365,618		$	3,072,250	$	—	$	514,170		$	3,586,420

	———
	(1) Represents the operating results of our wind facilities from January 29, 2015, the date of the acquisition of the First Wind operating portfolio, to March 31, 2015.
	(2) Income tax benefit is not allocated to the Company's Solar and Wind segments.
	(3) Represents total assets as of March 31, 2015 and December 31, 2014. Corporate assets include cash and cash equivalents; other current assets; corporate-level debt and related deferred financing costs, net and other assets.

Other_Comprehensive_Income_Los1

Other Comprehensive Income (Loss) (Tables)	3 Months Ended
	Mar. 31, 2015
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table presents the changes in each component of accumulated other comprehensive loss, net of tax:


	(In thousands)	Foreign Currency Translation Adjustments			Hedging Activities			Accumulated Other Comprehensive Loss
	Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, December 31, 2014	$	(1,149	)	$	(488	)	$	(1,637	)
	Net unrealized losses arising during the period	(3,275		)	(2,248		)	(5,523		)
	Reclassification of net losses to net income:
	Interest expense, net	—			2,857			2,857

	Other comprehensive (loss) income	$	(3,275	)	$	609		$	(2,666	)

	Accumulated other comprehensive (loss) income	(4,424		)	121			(4,303		)

	Other comprehensive (loss) income attributable to non-controlling interests	(1,862		)	168			(1,694		)

	Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, March 31, 2015	$	(2,562	)	$	(47	)	$	(2,609	)
Comprehensive Income (Loss)	The following table presents each component of other comprehensive loss and the related tax effects for the three months ended March 31, 2015:


	(In thousands)	Before Tax			Tax Effect			Net of Tax
	Foreign currency translation adjustments:
	Net unrealized losses arising during the period	$	(3,275	)	$	—		$	(3,275	)

	Hedging activities:
	Net unrealized losses arising during the period	(2,248		)	—			(2,248		)

	Reclassification of net losses into earnings	2,857			—			2,857

	Net change	609			—			609

	Other comprehensive loss	$	(2,666	)	$	—		$	(2,666	)

	Less: other comprehensive loss attributable to non-controlling interests, net of tax							(1,694		)
	Other comprehensive loss attributable to TerraForm Power, Inc. Class A stockholders							$	(972	)

Transactions_Between_Entities_2

Transactions Between Entities Under Common Control (Details) (USD $)	3 Months Ended				12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014	Dec. 31, 2013
	power_plant
	MW
Number of generation facilities	19
Solar energy generation system capacity (in megawatts)	161.1
Cash and cash equivalents	$153,423		$222,490		$468,554	$1,044
Due from SunEdison and affiliates, net	18,155				0
Prepaid expenses and other current assets	29,274				22,620
Property and equipment, net	3,429,630				2,554,904
Total assets	4,365,618	[1]	3,586,420	[1]	3,586,420
Current portion of long-term debt	229,517				84,104
Accounts payable, accrued expenses and other current liabilities	81,146				82,605
Due to SunEdison and affiliates, net	0				153,052
Long-term debt and financing lease obligations, less current portion	1,965,161				1,568,517
Total liabilities	2,484,404				2,046,161
Prepaid expenses and other current assets	4,420		-7,470		22,911
Accounts payable, accrued interest, and other current liabilities	417		18,112		4,236
Cash paid to third parties for renewable energy facility construction	-82,758		-103,047		-1,052,871
Deposit for acquisition of Call Right Projects					0
Borrowings of long-term debt	275,987		314,169		461,917
Principal payments on long-term debt	-2,910		-568		-339,570
Net increase in cash and cash equivalents	-315,130		221,446		467,940
Effect of exchange rate changes on cash and cash equivalents	-1		0		-430
December 31, 2014 As Reported
Cash and cash equivalents					468,393
Due from SunEdison and affiliates, net					19,640
Prepaid expenses and other current assets					21,840
Property and equipment, net					2,327,803
Current portion of long-term debt					80,133
Accounts payable, accrued expenses and other current liabilities					81,781
Due to SunEdison and affiliates, net					0
Long-term debt and financing lease obligations, less current portion					1,517,962
Prepaid expenses and other current assets					23,730
Accounts payable, accrued interest, and other current liabilities					3,371
Cash paid to third parties for renewable energy facility construction					-816,682
Deposit for acquisition of Call Right Projects					-34,000
Borrowings of long-term debt					399,806
Principal payments on long-term debt					-341,336
Net increase in cash and cash equivalents					467,513
Effect of exchange rate changes on cash and cash equivalents					-164
Acquired Call Rights Projects
Cash and cash equivalents					161
Due from SunEdison and affiliates, net					-19,640
Prepaid expenses and other current assets					780
Property and equipment, net					227,101
Total assets					208,402
Current portion of long-term debt					3,971
Accounts payable, accrued expenses and other current liabilities					824
Due to SunEdison and affiliates, net					153,052
Long-term debt and financing lease obligations, less current portion					50,555
Total liabilities					208,402
Prepaid expenses and other current assets					-819
Accounts payable, accrued interest, and other current liabilities					865
Cash paid to third parties for renewable energy facility construction					-236,189
Deposit for acquisition of Call Right Projects					34,000
Borrowings of long-term debt					62,111
Principal payments on long-term debt					1,766
Net increase in cash and cash equivalents					427
Effect of exchange rate changes on cash and cash equivalents					($266)

[1]	Corporate assets include cash and cash equivalents; other current assets; corporate-level debt and related deferred financing costs, net and other assets.

Acquisitions_Narrative_Details

Acquisitions - Narrative (Details)

3 Months Ended

12 Months Ended

3 Months Ended

0 Months Ended

3 Months Ended

0 Months Ended

3 Months Ended

12 Months Ended

1 Months Ended

0 Months Ended

3 Months Ended

0 Months Ended

Mar. 31, 2015

Mar. 31, 2014

Dec. 31, 2014

Mar. 31, 2015

Apr. 28, 2015

Mar. 31, 2015

Apr. 28, 2015

Jun. 30, 2015

Apr. 28, 2015

Mar. 31, 2015

Dec. 31, 2014

Mar. 31, 2015

Apr. 29, 2015

Jan. 29, 2015

Mar. 31, 2015

1-May-15

4-May-15

USD ($)

DG 2014 Portfolio 1

DG Portfolios

DG 2015 Portfolio 2

Minimum

Maximum

Weighted average

England and Wales

First Wind

Acquired Projects

Atlantic Power

Moose Power

Invenergy

Subsequent Event

USD ($)

Subsequent Event

Scenario, Forecast

Energy revenue contracts

USD ($)

Subsequent Event

USD ($)

Energy Equipment

Wind Power Systems

Renewable energy facilities

USD ($)

Idaho and Oklahoma

Subsequent Event

First Invenergy Plant

Second Invenergy Plant

USD ($)

Subsequent Event

power_plant

USD ($)

Weighted average

USD ($)

CAD

USD ($)

Subsequent Event

USD ($)

power_plant

Energy revenue contracts

power_plant

Business Acquisition [Line Items]

Solar energy generation system capacity (in megawatts)

161.1

6.2

3.2

8.8

152.1

23.5

521.1

500

21.1

521

1.8

Purchase price, net of acquired cash

$1,604,472,000

$810,436,000

Operating revenues, net

70,515,000

11,880,000

22,100,000

Net loss

83,660,000

1,081,000

6,200,000

Acquisition costs including amounts for affiliates

14,200,000

Weighted Average Amortization Period

20 years

21 years

18 years

Purchase price for acquisition

350,000,000

Adjustment to fixed assets

-4,900,000

Adjustment to intangibles

3,200,000

Adjust to accounts payable

2,500,000

Adjustment for all other accounts

700,000

Estimated useful lives of intangible assets (in years)

10 years

25 years

Number Of generation facilities

Consideration transferred

18,000,000

2,300,000

8,700,000

3,900,000

81,900,000

9,800,000

9,300,000

11,300,000

55,000,000

Long-term debt

1,900,000

Debt assumed

$174,300,000

$31,200,000

Acquisitions_Pro_Forma_table_D

Acquisitions - Pro Forma table (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Business Combinations [Abstract]
Operating revenues	$39,851	$58,281
Net loss (income)	$6,987	$21,987

Acquisitions_Acquisition_Price

Acquisitions - Acquisition Price Allocation table (Details) (USD $)	Mar. 31, 2015	Jan. 29, 2015
In Thousands, unless otherwise specified	Mar. 31, 2015	Jan. 29, 2015
Business Acquisition [Line Items]
Property and equipment	$1,922,601
Accounts receivable	32,784
Restricted cash	43,530
Deferred income taxes	21,118
Other assets	88,133
Intangible assets	442,472
Total assets acquired	2,550,638
Long-term debt	611,294
Accounts payable, accrued expenses and other current liabilities	40,726
Asset retirement obligations	47,506
Deferred income taxes	26,181
Total liabilities assumed	725,707
Non-controlling interest	220,459
Purchase price, net of cash acquired	1,604,472
First Wind
Business Acquisition [Line Items]
Property and equipment	803,103
Accounts receivable	9,378
Restricted cash	6,630
Deferred income taxes	0
Other assets	68,671
Intangible assets	125,671
Total assets acquired	1,013,453
Long-term debt	59,816
Accounts payable, accrued expenses and other current liabilities	9,934
Asset retirement obligations	12,403
Deferred income taxes	0
Total liabilities assumed	82,153
Non-controlling interest	120,864
Purchase price, net of cash acquired		810,436
Mt. Signal
Business Acquisition [Line Items]
Property and equipment	649,005
Accounts receivable	11,617
Restricted cash	22,165
Deferred income taxes	0
Other assets	12,621
Intangible assets	117,925
Total assets acquired	813,333
Long-term debt	413,464
Accounts payable, accrued expenses and other current liabilities	24,813
Asset retirement obligations	4,656
Deferred income taxes	0
Total liabilities assumed	442,933
Non-controlling interest	78,745
Purchase price, net of cash acquired	291,655
Capital Dynamics
Business Acquisition [Line Items]
Property and equipment	216,771
Accounts receivable	2,309
Restricted cash	15
Deferred income taxes	21,118
Other assets	1,490
Intangible assets	71,859
Total assets acquired	313,562
Long-term debt	0
Accounts payable, accrued expenses and other current liabilities	1,194
Asset retirement obligations	13,073
Deferred income taxes	25,191
Total liabilities assumed	39,458
Non-controlling interest	16,600
Purchase price, net of cash acquired	257,504
2014 Preliminary Other Acquisitions
Business Acquisition [Line Items]
Property and equipment	102,788
Accounts receivable	7,100
Restricted cash	5,564
Deferred income taxes	0
Other assets	1,455
Intangible assets	21,656
Total assets acquired	138,563
Long-term debt	65,084
Accounts payable, accrued expenses and other current liabilities	3,499
Asset retirement obligations	6,622
Deferred income taxes	990
Total liabilities assumed	76,195
Non-controlling interest	2,850
Purchase price, net of cash acquired	59,518
2014 Finalized Other Acquisitions
Business Acquisition [Line Items]
Property and equipment	150,934
Accounts receivable	2,380
Restricted cash	9,156
Deferred income taxes	0
Other assets	3,896
Intangible assets	105,361
Total assets acquired	271,727
Long-term debt	72,930
Accounts payable, accrued expenses and other current liabilities	1,286
Asset retirement obligations	10,752
Deferred income taxes	0
Total liabilities assumed	84,968
Non-controlling interest	1,400
Purchase price, net of cash acquired	$185,359

Acquisitions_Acquisition_of_Ca

Acquisitions - Acquisition of Call Right Projects (Details) (Call Right Projects, USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified	Mar. 31, 2015
Call Right Projects
Acquisition of Call Right Projects [Line Items]
Current assets	$19,424
Property, plant and equipment	274,685
Non-current assets	24,912
Total assets acquired	319,021
Long-term debt	174,467
Other liabilities	71,592
Total liabilities assumed	246,059
Net assets acquired	$72,962

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	3 Months Ended
Property and Equipment (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Property, Plant and Equipment, Net, by Type [Abstract]
Total property and equipment	$3,429,630,000		$2,554,904,000
Depreciation, accretion and amortization	25,100,000	3,100,000
Capitalized interest costs and amortization of deferred financing costs	641,000	2,110,000
Renewable energy facilities
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment - gross	3,404,264,000		2,220,401,000
Construction in progress - renewable energy facilities	-74,957,000		-50,080,000
Total property and equipment	3,329,307,000		2,170,321,000
Construction in progress - renewable energy facilities
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment - gross	100,323,000		384,583,000
Construction in progress			$100,323,000

Intangible_Assets_Details

Intangible Assets (Details) (USD $)	3 Months Ended		12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Amortization of intangible assets	($336)	$0
Depreciation, accretion and amortization	31,891	3,241
Energy revenue contracts
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Gross Carrying Amount	463,636		371,765
Accumulated Amortization	-5,329		-6,169
Accumulated Currency Translation Adjustment	-3,379		-3,923
Net Book Value	454,928		361,673
Amortization of intangible assets	5,329	0
Amortization of intangibles recorded as a reduction of revenue	-336
Depreciation, accretion and amortization	$5,665
Energy revenue contracts \| Weighted average
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Weighted Average Amortization Period	20 years		21 years
Energy revenue contracts \| Minimum
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Estimated useful lives of intangible assets (in years)	10 years
Energy revenue contracts \| Maximum
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Estimated useful lives of intangible assets (in years)	25 years

Variable_Interest_Entities_Det

Variable Interest Entities (Details) (Consolidated variable interest entities where Terra LLC is primary beneficiary, USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	entity	entity
Consolidated variable interest entities where Terra LLC is primary beneficiary
Variable Interest Entity [Line Items]
Number of variable interest entities of which the company is the primary beneficiary of	10	9
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Current assets	$64,973	$69,955
Noncurrent assets	1,803,709	1,756,276
Total assets	1,868,682	1,826,231
Current liabilities	57,898	64,324
Noncurrent liabilities	729,644	707,989
Total liabilities	$787,542	$772,313

Longterm_Debt_Debt_Schedule_ta

Long-term Debt - Debt Schedule table (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014	Jan. 28, 2015
Debt Instrument [Line Items]
Effective interest	5.90%	[1]
Total Principal long-term debt and financing lease obligations	$2,199,653		$1,651,148
Less current maturities	-229,517		-84,104
Net unamortized (discount) premium	-4,975		1,473
Long-term debt and financing lease obligations, less current portion	1,965,161		1,568,517
Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Effective interest	2.70%
Total Principal long-term debt and financing lease obligations	150,000		0
Permanent Financing
Debt Instrument [Line Items]
Effective interest	6.10%	[1],[2]
Total Principal long-term debt and financing lease obligations	882,865		886,149
Debt at variable rate	38.00%
Debt at fixed rate	62.00%
Permanent Financing \| Senior Notes, due 2023
Debt Instrument [Line Items]
Stated interest rate (in percent)	5.90%			5.88%
Total Principal long-term debt and financing lease obligations	800,000		0
Permanent Financing \| Permanent Financing
Debt Instrument [Line Items]
Fixed effective interest rate	5.30%	[3]
Total Principal long-term debt and financing lease obligations	0		573,500
Construction financing
Debt Instrument [Line Items]
Effective interest	2.90%	[1]
Total Principal long-term debt and financing lease obligations	212,072		97,518
Financing lease obligations
Debt Instrument [Line Items]
Effective interest	5.10%	[1]
Total Principal long-term debt and financing lease obligations	$154,716		$93,981

[1]	Represents the weighted average effective interest rate as of MarchB 31, 2015.
[2]	Includes debt at variable or fixed interest rates. As of MarchB 31, 2015, 38% of this balance had a variable interest rate and 62% of this balance had a fixed interest rate.
[3]	The Company entered into an interest rate swap agreement (see Note 10. Derivatives) fixing the interest rate at 5.33%, which was terminated upon repayment of the Term Loan.

Longterm_Debt_Narrative_Detail

Long-term Debt - Narrative (Details) (USD $)	3 Months Ended		0 Months Ended
Long-term Debt - Narrative (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Jan. 29, 2015	Jun. 30, 2015	Jan. 28, 2015	Dec. 31, 2014	1-May-15
Debt Instrument [Line Items]
Total Principal long-term debt and financing lease obligations	$2,199,653,000					$1,651,148,000
Loss on extinguishment of debt	20,038,000	0
Bull Hill Financing Due 2023
Debt Instrument [Line Items]
Amount of financing obligation	59,800,000
Line of Credit
Debt Instrument [Line Items]
Bridge facility	515,000,000
Line of Credit
Debt Instrument [Line Items]
Loss on extinguishment of debt	1,300,000
Secured Debt
Debt Instrument [Line Items]
Loss on extinguishment of debt	12,000,000
Secured Debt \| First Wind
Debt Instrument [Line Items]
Loss on extinguishment of debt	6,400,000
Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Total Principal long-term debt and financing lease obligations	150,000,000					0
Aggregate principal amount					550,000,000
Ability to increase commitments			725,000,000
Required prepayment percentage of disallowed indebtedness	100.00%
Percentage of borrower's domestic entities' equity as collateral	100.00%
Percentage of borrower's foreign entities' equity as collateral	65.00%
Line of Credit \| Revolving Credit Facility \| Subsequent Event
Debt Instrument [Line Items]
Aggregate principal amount							650,000,000
Ability to increase commitments							100,000,000
Line of Credit \| Revolving Credit Facility \| Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)			2.50%
Line of Credit \| Revolving Credit Facility \| Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)			1.50%
Line of Credit \| Revolving Credit Facility \| Scenario, Forecast \| Eurodollar \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)				2.25%
Line of Credit \| Revolving Credit Facility \| Scenario, Forecast \| Eurodollar \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)				2.75%
Line of Credit \| Revolving Credit Facility \| Scenario, Forecast \| Base Rate \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)				1.25%
Line of Credit \| Revolving Credit Facility \| Scenario, Forecast \| Base Rate \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (in percent)				1.75%
Secured Debt
Debt Instrument [Line Items]
Total Principal long-term debt and financing lease obligations	882,865,000					886,149,000
Secured Debt \| Senior Notes, due 2023
Debt Instrument [Line Items]
Total Principal long-term debt and financing lease obligations	800,000,000					0
Face amount of debt instrument					800,000,000
Stated interest rate (in percent)	5.90%				5.88%
Proceeds from debt issuance as a percentage of face value					99.21%
Secured Debt \| Secured Debt
Debt Instrument [Line Items]
Total Principal long-term debt and financing lease obligations	$0					$573,500,000

Longterm_Debt_Debt_Maturities_

Long-term Debt - Debt Maturities table (Details)	Mar. 31, 2015		Dec. 31, 2014	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	Mar. 31, 2015	Mar. 31, 2015	Mar. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
	USD ($)		USD ($)	Secured Debt	Secured Debt	Secured Debt	Secured Debt	Secured Debt	Secured Debt	Revolving Credit Facility	Revolving Credit Facility
				USD ($)	USD ($)	SunE Perpetual Lindsay	SunE Perpetual Lindsay	Fairwinds and Crundale and Call Right Projects	Fairwinds and Crundale and Call Right Projects	Line of Credit	Line of Credit
						USD ($)	CAD	USD ($)	GBP (£)	USD ($)	USD ($)
Debt Instrument [Line Items]
Remainder of 2015	$227,879,000	[1]
2016	264,521,000	[2]
2017	37,902,000
2018	39,337,000
2019	50,104,000
Thereafter	1,579,910,000
Total	2,199,653,000		1,651,148,000	882,865,000	886,149,000					150,000,000	0
Long-term debt, amount outstanding						$37,800,000	47,800,000	$225,600,000	£ 152,500,000

[1]	The amount of long-term debt due in 2015 includes CAD 47.8 million (USD $37.8 million) of construction debt for SunE Perpetual Lindsay, which will be repaid by SunEdison in the third quarter of 2015 and an outstanding balance of $150.0 million on our Revolver. (2) The amount of long-term debt due in 2016 includes GBP 152.5 million (USD $225.6 million) of debt for the Fairwinds & Crundale facilities and the U.K. Call Right Projects.
[2]	The amount of long-term debt due in 2016 includes GBP 152.5 million (USD $225.6 million) of debt for the Fairwinds & Crundale facilities and the U.K. Call Right Projects.

Income_Taxes_Effective_tax_rat

Income Taxes - Effective tax rate table (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014
Income Tax Disclosure [Abstract]
Loss before income tax benefit	($83,705)		($1,538)
Income tax benefit	($45)	[1]	($457)	[1]
Effective tax rate	0.10%		29.70%

[1]	Income tax benefit is not allocated to the Company's Solar and Wind segments.

Income_Taxes_Narrative_Details

Income Taxes - Narrative (Details)	3 Months Ended
Income Taxes - Narrative (Details)	Mar. 31, 2015
Income Taxes [Line Items]
Ownership percentage of Terra LLC	44.90%
Statutory tax rate percentage	35.00%
Riverstone
Income Taxes [Line Items]
Ownership percentage by other entities	4.70%
SunEdison
Income Taxes [Line Items]
Ownership percentage by other entities	50.40%

Derivatives_Fair_Value_of_Deri

Derivatives - Fair Value of Derivatives table (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Derivatives, Fair Value [Line Items]
Assets	$44,982	$1,811
Derivative asset, offset	-1,936	0
Derivative Asset	43,046	1,811
Liabilities	6,407	3,889
Derivative liability, offset	-1,936	0
Derivative Liability	4,471	3,889
Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Assets	11,151	0
Derivative asset, offset	-1,155	0
Derivative Asset	9,996	0
Other assets
Derivatives, Fair Value [Line Items]
Assets	33,831	1,811
Derivative asset, offset	-781	0
Derivative Asset	33,050	1,811
Accounts payable and other current liabilities
Derivatives, Fair Value [Line Items]
Liabilities	845	3,889
Derivative liability, offset	0	0
Derivative Liability	845	3,889
Other long-term liabilities
Derivatives, Fair Value [Line Items]
Liabilities	5,562	0
Derivative liability, offset	-1,936	0
Derivative Liability	3,626	0
Interest rate swaps \| Hedging Contracts
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	1,315	1,925
Interest rate swaps \| Hedging Contracts \| Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Assets	0	0
Interest rate swaps \| Hedging Contracts \| Other assets
Derivatives, Fair Value [Line Items]
Assets	0	0
Interest rate swaps \| Hedging Contracts \| Accounts payable and other current liabilities
Derivatives, Fair Value [Line Items]
Liabilities	845	1,925
Interest rate swaps \| Hedging Contracts \| Other long-term liabilities
Derivatives, Fair Value [Line Items]
Liabilities	470	0
Interest rate swaps \| Derivatives Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Assets	0	0
Liabilities	1,381	1,279
Interest rate swaps \| Derivatives Not Designated as Hedges \| Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Assets	0	0
Interest rate swaps \| Derivatives Not Designated as Hedges \| Other assets
Derivatives, Fair Value [Line Items]
Assets	0	0
Interest rate swaps \| Derivatives Not Designated as Hedges \| Accounts payable and other current liabilities
Derivatives, Fair Value [Line Items]
Liabilities	0	1,279
Interest rate swaps \| Derivatives Not Designated as Hedges \| Other long-term liabilities
Derivatives, Fair Value [Line Items]
Liabilities	1,381	0
Foreign Currency Contracts \| Derivatives Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Assets	4,530	1,811
Liabilities	3,711	685
Foreign Currency Contracts \| Derivatives Not Designated as Hedges \| Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Assets	2,669	0
Foreign Currency Contracts \| Derivatives Not Designated as Hedges \| Other assets
Derivatives, Fair Value [Line Items]
Assets	1,861	1,811
Foreign Currency Contracts \| Derivatives Not Designated as Hedges \| Accounts payable and other current liabilities
Derivatives, Fair Value [Line Items]
Liabilities	0	685
Foreign Currency Contracts \| Derivatives Not Designated as Hedges \| Other long-term liabilities
Derivatives, Fair Value [Line Items]
Liabilities	3,711	0
Commodity contracts \| Derivatives Not Designated as Hedges
Derivatives, Fair Value [Line Items]
Assets	40,452	0
Liabilities	0	0
Commodity contracts \| Derivatives Not Designated as Hedges \| Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Assets	8,482	0
Commodity contracts \| Derivatives Not Designated as Hedges \| Other assets
Derivatives, Fair Value [Line Items]
Assets	31,970	0
Commodity contracts \| Derivatives Not Designated as Hedges \| Accounts payable and other current liabilities
Derivatives, Fair Value [Line Items]
Liabilities	0	0
Commodity contracts \| Derivatives Not Designated as Hedges \| Other long-term liabilities
Derivatives, Fair Value [Line Items]
Liabilities	$0	$0

Derivatives_Notional_table_Det

Derivatives - Notional table (Details)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2014	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Interest rate swaps	Interest rate swaps	Interest rate swaps	Interest rate swaps	Foreign Currency Contracts	Foreign Currency Contracts	Foreign Currency Contracts	Foreign Currency Contracts	Commodity contracts	Commodity contracts
	Hedging Contracts	Hedging Contracts	Derivatives not designated as hedges	Derivatives not designated as hedges	Derivatives not designated as hedges	Derivatives not designated as hedges	Derivatives not designated as hedges	Derivatives not designated as hedges	Derivatives not designated as hedges	Derivatives not designated as hedges
	USD ($)	USD ($)	USD ($)	USD ($)	CAD	GBP (£)	CAD	GBP (£)	MWh	MWh
Derivative [Line Items]
Notional amount	$50,150	$349,213	$16,857	$16,861	25,097	£ 56,348	25,415	£ 58,710
Nonmonetary notional amount									2,248,000	0

Derivatives_GainLoss_table_Det

Derivatives - Gain/Loss table (Details) (Hedging Contracts, USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Interest expense, net \| Interest rate swaps
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$236	$0
Loss on foreign currency exchange, net \| Foreign Currency Contracts
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net	97	0
Operating revenues, net \| Commodity contracts
Derivative [Line Items]
Derivative, Gain (Loss) on Derivative, Net	$4,259	$0

Derivatives_Interest_Rate_Swap

Derivatives - Interest Rate Swaps Designated as Cash Flow Hedges table (Details) (Interest expense, net, Interest rate swaps, USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Interest expense, net \| Interest rate swaps
Derivative [Line Items]
Loss Recognized in Other Comprehensive Income (Effective Portion)	$2,248	$0
Amount of Loss Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion)	2,857	0
Amount of Loss Recognized in Income (Ineffective Portion and Amount Excluded from Effectiveness Testing)	$0	$0

Derivatives_Narrative_Details

Derivatives - Narrative (Details) (USD $)	3 Months Ended
Derivatives - Narrative (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Loss on extinguishment of debt	$20,038,000	$0
Letter of Credit \| Commodity contracts
Derivative Instruments, Gain (Loss) [Line Items]
Collateral already posted	19,500,000		0
Term Loan \| Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Loss on extinguishment of debt	300,000
Term Loan \| Cash Flow Hedging \| Interest rate swaps \| Hedging Contracts \| Accumulated Other Comprehensive Income (Loss)
Derivative Instruments, Gain (Loss) [Line Items]
Loss previously recognized in other comp. income	2,500,000
Secured Debt \| Interest rate swaps
Derivative Instruments, Gain (Loss) [Line Items]
Amount expected to be reclassified into earnings	$800,000

Fair_Value_of_Financial_Instru2

Fair Value of Financial Instruments - Debt and Levels 1-3 tables (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Long-term debt, including current portion
Carrying Amount	$2,194,678	$1,652,621
Assets and Liabilities
Assets	44,982	1,811
Liabilities	6,407	3,889
Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	43,046	1,811
Liabilities	4,471	3,889
Interest rate swaps \| Fair Value, Measurements, Recurring
Assets and Liabilities
Liabilities	2,696	3,204
Foreign Currency Contracts \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	2,594	1,811
Liabilities	1,775	685
Commodity contracts \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	40,452	0
Level 1 \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	0	0
Level 1 \| Interest rate swaps \| Fair Value, Measurements, Recurring
Assets and Liabilities
Liabilities	0	0
Level 1 \| Foreign Currency Contracts \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	0	0
Level 1 \| Commodity contracts \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Level 2
Long-term debt, including current portion
Fair Value	2,249,970	1,659,883
Level 2 \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	43,046	1,811
Liabilities	4,471	3,889
Level 2 \| Interest rate swaps \| Fair Value, Measurements, Recurring
Assets and Liabilities
Liabilities	2,696	3,204
Level 2 \| Foreign Currency Contracts \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	2,594	1,811
Liabilities	1,775	685
Level 2 \| Commodity contracts \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	40,452	0
Level 3 \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	0	0
Level 3 \| Interest rate swaps \| Fair Value, Measurements, Recurring
Assets and Liabilities
Liabilities	0	0
Level 3 \| Foreign Currency Contracts \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	0	0
Liabilities	0	0
Level 3 \| Commodity contracts \| Fair Value, Measurements, Recurring
Assets and Liabilities
Assets	$0	$0

Stockholders_Equity_Narrative_

Stockholder's Equity - Narrative (Details) (USD $)	3 Months Ended		0 Months Ended
Stockholder's Equity - Narrative (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Jan. 22, 2015	Dec. 22, 2014
Class of Stock [Line Items]
Proceeds from issuance of Class A common stock	$342,192,000	$0
Ownership percentage by parent	44.90%
SunEdison
Class of Stock [Line Items]
Ownership percentage by other entities	50.40%
Riverstone
Class of Stock [Line Items]
Ownership percentage by other entities	4.70%
Class A Common Stock
Class of Stock [Line Items]
New issuances of common stock (in shares)			13,800,000
Proceeds from issuance of Class A common stock			390,600,000
Dividends payable per share				$0.27
Dividends payable (annualized basis) per share				$1.08
Class A Common Stock \| Over-Allotment Option
Class of Stock [Line Items]
New issuances of common stock (in shares)			1,800,000
Class B common stock
Class of Stock [Line Items]
Payments for repurchase of common stock			$50,900,000

Stockholders_Equity_Shares_Out

Stockholder's Equity - Shares Outstanding Table (Details)	3 Months Ended
Stockholder's Equity - Shares Outstanding Table (Details)	Mar. 31, 2015		Dec. 31, 2014
Class of Stock [Line Items]
Common stock outstanding (shares)	124,518,344
Restricted Stock Award
Class of Stock [Line Items]
Shares excluded from calculation (shares)	2,445,464
Class A Common Stock
Class of Stock [Line Items]
Common stock outstanding (shares)	55,952,000		42,218,000
Class B common stock
Class of Stock [Line Items]
Common stock outstanding (shares)	62,717,000		64,526,000
Class B1 common stock
Class of Stock [Line Items]
Common stock outstanding (shares)	5,840,000		5,840,000
Multiple Shareholders \| Class A Common Stock
Class of Stock [Line Items]
Common stock outstanding (shares)	55,951,690	[1]
SunEdison \| Class B common stock
Class of Stock [Line Items]
Common stock outstanding (shares)	62,726,654
Riverstone \| Class B1 common stock
Class of Stock [Line Items]
Common stock outstanding (shares)	5,840,000

[1]	* Class A common stockholders are comprised of: public and private investors, executive officers, management and personnel who provide services to the Company. The par value of Class A common stock reflected on the unaudited consolidated balance sheets and unaudited consolidated statement of stockholders' equity excludes 2,445,464 shares of unvested restricted Class A common stock awards.

Stockbased_Compensation_Narrat

Stock-based Compensation - Narrative (Details) (USD $)	0 Months Ended	3 Months Ended
Stock-based Compensation - Narrative (Details) (USD $)	Mar. 10, 2015	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Price ($ per share)		$36.51
Unrecognized compensation expense on options		$1,000,000
Class A Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for issuance		1,696,198
Restricted Stock Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		2,500,000
Unrecognized compensation cost		1,100,000
Period for unrecognized compensation cost recognition		2 years
Number of shares granted		0
Weighted average grant date fair value per share for shares granted		$0
Employee Stock Option and Restricted Stock \| General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		5,144,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		2,000,000
Unrecognized compensation cost		18,900,000
Period for unrecognized compensation cost recognition		5 years
Number of shares granted	53,700	1,104,200
Weighted average grant date fair value per share for shares granted		$34.01
Percentage of total award represented by each type of award		20.00%
Vesting period		4 years
Percentage of shares vesting		25.00%
Aggregate fair value	1,600,000
Restricted Stock Units (RSUs) \| SunEdison
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted		107,200
Restricted Stock Units (RSUs) \| SunEdison
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		200,000
Number of shares granted		960,200
Weighted average grant date fair value per share for shares granted		$34.23
Restricted Stock Units (RSUs) \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of total award represented by each type of award		80.00%
Vesting period		5 years
Number of performance tiers		3
Percentage of shares vesting		33.00%
Restricted Stock Units (RSUs) \| Performance Shares - First Tier
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vesting		50.00%
Restricted Stock Units (RSUs) \| Performance Shares - Second Tier
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vesting		75.00%
Restricted Stock Units (RSUs) \| Performance Shares - Third Tier
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vesting		100.00%
Restricted Stock Units (RSUs) \| Performance Shares - First Tranche
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vesting		50.00%
Restricted Stock Units (RSUs) \| Performance Shares - Second Tranche
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vesting		30.00%
Restricted Stock Units (RSUs) \| Performance Shares - Third Tranche
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vesting		20.00%
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$200,000
Period for unrecognized compensation cost recognition		4 years

Stockbased_Compensation_Tables1

Stock-based Compensation - Tables (Details) (USD $)	0 Months Ended	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 10, 2015	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Shares modified		66,294
Weighted average grant date fair value per share for shares modified		$35.05
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Beginning balance number of option shares		150,000
Beginning balance weighted average grant date fair value per option		$29.31
Number of options granted		0
Weighted average grant date fair value per share for options granted		$0
Aggregate intrinsic value for options		$1,080
Ending balance number of option shares		150,000
Ending balance weighted average grant date fair value per option		$29.31
Number of options exercisable		18,750
Weighted average grant date fair value per share for options exercisable		$29.31
Aggregate intrinsic value for options exercisable		$135
Restricted Stock Award
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance number of shares		4,876,567
Beginning balance weighted average grant date fair value per share		$1.12
Restricted stock granted (in shares)		0
Weighted average grant date fair value per share for shares granted		$0
Shares forfeited		-132,588
Weighted average grant date fair value per share for shares forfeited		$0.68
Ending balance number of shares		4,810,273
Ending balance weighted average grant date fair value per share		$1.60
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance number of shares		825,943
Beginning balance weighted average grant date fair value per share		$27.37
Restricted stock granted (in shares)	53,700	1,104,200
Weighted average grant date fair value per share for shares granted		$34.01
Ending balance number of shares		1,930,143
Ending balance weighted average grant date fair value per share		$31.17

Loss_Per_Share_Details

Loss Per Share (Details) (USD $)	3 Months Ended
In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015
Class A common stock - Basic and diluted
Class A common stock - Basic and Diluted (shares)	49,694,000
EPS Numerator:
Net loss attributable to TerraForm Power, Inc. Class A common stockholders subsequent to initial public offering	($28,116)
EPS Denominator:
Weighted-average number of shares outstanding, basic (shares)	49,694,000
Weighted-average number of shares outstanding, diluted (shares)	49,694,000	[1]
Basic earnings (loss) per share ($ per share)	($0.57)
Diluted earnings (loss) per share ($ per share)	($0.57)	[1]
Class A Common Stock
Class A common stock - Basic and diluted
Class A common stock - Basic and Diluted (shares)	49,694,000
EPS Numerator:
Net loss attributable to TerraForm Power, Inc. Class A common stockholders subsequent to initial public offering	-28,116
Net Ioss attributable to TerraForm Power, Inc. Class A common stockholders, diluted	($28,116)	[1]
Class B common stock
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Shares excluded from calculation (shares)	62,726,654
Class B1 common stock
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Shares excluded from calculation (shares)	5,840,000
Restricted Stock Award
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Shares excluded from calculation (shares)	2,445,464
Restricted Stock Units (RSUs)
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Shares excluded from calculation (shares)	1,930,143
Equity Option
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Shares excluded from calculation (shares)	150,000

[1]	The computations for diluted earnings (loss) per share for the three months ended March 31, 2015B excludes approximatelyB 62,726,654 shares of Class B common stock, 5,840,000 shares of Class B1 common stock, 2,445,464 of unvested RSAs, 1,930,143 RSUs and 150,000 options to purchase the Company's shares because the effect would have been anti-dilutive.

Noncontrolling_Interests_Detai

Non-controlling Interests (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015		Mar. 31, 2014	Dec. 31, 2014
Noncontrolling Interest [Line Items]
Non-controlling interests	$1,152,614			$1,044,529
Equity Reallocation	93,991
Payment for purchase	54,694
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
As of December 31, 2014	24,338
Consolidation of redeemable non-controlling interests	1,348
Sale of membership interests in projects	403
Distributions	-716
Less: Net loss attributable to redeemable non-controlling interests	-169		0
As of March 31, 2015	25,204
Capital
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
As of December 31, 2014	24,338
Consolidation of redeemable non-controlling interests	1,348
Sale of membership interests in projects	403
Distributions	-716
Less: Net loss attributable to redeemable non-controlling interests	0
As of March 31, 2015	25,373
Accumulated Other Comprehensive Income (Loss)
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
As of December 31, 2014	0
Consolidation of redeemable non-controlling interests	0
Sale of membership interests in projects	0
Distributions	0
Less: Net loss attributable to redeemable non-controlling interests	-169
As of March 31, 2015	-169
Investor
Noncontrolling Interest [Line Items]
Ownership percentage by partner	92.00%
SunEdison
Noncontrolling Interest [Line Items]
Ownership percentage by partner	50.40%
SunEdison \| Terra LLC \| Investor
Noncontrolling Interest [Line Items]
Non-controlling interests	788,568	[1]		722,342	[1]
Riverstone
Noncontrolling Interest [Line Items]
Ownership percentage by partner	4.70%
Riverstone \| Terra LLC \| Investor
Noncontrolling Interest [Line Items]
Non-controlling interests	73,418	[1]		65,376	[1]
Terra LLC \| Terra LLC
Noncontrolling Interest [Line Items]
Non-controlling interests	861,986			787,718
Miscellaneous Projects \| Miscellaneous Projects
Noncontrolling Interest [Line Items]
Non-controlling interests	$290,628			$256,811

[1]	Reflects an equity reallocation of $94.0 million due to a quarterly adjustment of capital balances to reflect respective ownership percentages as of the balance sheet date.

Commitments_and_Contingencies_

Commitments and Contingencies (Details) (USD $)	Mar. 31, 2015	Mar. 05, 2015
In Millions, unless otherwise specified	MW	MW
Loss Contingencies [Line Items]
Outstanding letters of credit	$162.70
Solar energy generation system capacity (in megawatts)	161.1
United Kingdom \| Norrington
Loss Contingencies [Line Items]
Solar energy generation system capacity (in megawatts)		11.2

Related_Parties_Details

Related Parties (Details) (USD $)	3 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Jul. 23, 2014	Mar. 30, 2015	Jan. 09, 2015	Apr. 27, 2015	Dec. 31, 2014	Jan. 28, 2015
	MW	Mar. 31, 2014	Jul. 23, 2014	power_plant	Jan. 09, 2015	Apr. 27, 2015	Dec. 31, 2014	Jan. 28, 2015
Related Party Transaction [Line Items]
General and administrative - affiliate	$6,027,000	$1,590,000
Cost of operations - affiliate	3,643,000	352,000
Due from SunEdison and affiliates, net	18,155,000						0
Due to SunEdison and affiliates, net	0						153,052,000
Quarterly Distribution Rights, Level Two, Percentage	85.00%
Quarterly Distribution Rights, Level Three	75.00%
Quarterly Distribution Rights, Level One ($ per share)	$0.34
Quarterly Distribution Rights, Level Two ($ per share)	$0.40
Quarterly Distribution Rights, Level Three ($ per share)	$0.45
Quarterly Distribution Rights, Level Four, Percentage	50.00%
Solar energy generation system capacity (in megawatts)	161.1
Senior Notes, due 2023 \| Secured Debt
Related Party Transaction [Line Items]
Face amount of debt instrument								800,000,000
Stated interest rate (in percent)	5.90%							5.88%
Incentive Distribution Rights
Related Party Transaction [Line Items]
Quarterly Distribution Rights, Level One, Percentage	15.00%
Quarterly Distribution Rights, Level Two, Percentage	25.00%
Quarterly Distribution Rights, Minimum Quarterly Distribution ($ per share)	$0.23
Quarterly Distribution Rights, Level Three	50.00%
Minimum Quarterly Distribution
Related Party Transaction [Line Items]
Quarterly Distribution Rights, Level One, Percentage	150.00%
Quarterly Distribution Rights, Level Two, Percentage	175.00%
Quarterly Distribution Rights, Level Three	200.00%
SunEdison
Related Party Transaction [Line Items]
Incentives - affiliate	200,000	100,000
SunEdison \| Management Services Agreement
Related Party Transaction [Line Items]
Management fee due to SunEdison in 2015-2017 (in percent of Terra LLC's cash available for distribution)			2.50%
Management fee due to SunEdison in 2015 not to exceed			4,000,000
Management fee due to SunEdison in 2016 not to exceed			7,000,000
Management fee due to SunEdison in 2017 not to exceed			9,000,000
Payments for related party transactions	700,000
General and administrative - affiliate	6,900,000
SunEdison \| Corporate Overhead Allocation
Related Party Transaction [Line Items]
General and administrative - affiliate	6,000,000	1,600,000
SunEdison \| Interest Expense Paid by Parent
Related Party Transaction [Line Items]
Interest on loan to be paid by SunEdison not to exceed			48,000,000
Equity contribution	4,000,000
Holders of Incentive Distribution Rights
Related Party Transaction [Line Items]
Quarterly Distribution Rights, Level Two, Percentage	15.00%
Quarterly Distribution Rights, Level Three	25.00%
Quarterly Distribution Rights, Level Four, Percentage	50.00%
Affiliated Entity \| Membership Interest Purchase and Sale Agreement
Related Party Transaction [Line Items]
Number of businesses acquired				2
Deposit				378,200,000
Affiliated Entity \| Membership Interest Purchase and Sale Agreement \| Maine
Related Party Transaction [Line Items]
Solar energy generation system capacity (in megawatts)				147.6
Affiliated Entity \| Membership Interest Purchase and Sale Agreement \| Texas
Related Party Transaction [Line Items]
Solar energy generation system capacity (in megawatts)				200
Affiliated Entity \| Project Support Agreement \| SunEdison
Related Party Transaction [Line Items]
Solar energy generation system capacity (in megawatts)					69
Affiliated Entity \| Project Support Agreement \| SunEdison \| Subsequent Event
Related Party Transaction [Line Items]
Solar energy generation system capacity (in megawatts)						10
Affiliated Entity \| Project Support Agreement \| Chile \| SunEdison
Related Party Transaction [Line Items]
Deposit					18,000,000
Affiliated Entity \| Project Support Agreement \| England \| SunEdison \| Subsequent Event
Related Party Transaction [Line Items]
Deposit						$10,000,000
SunEdison \| Incentive Distribution Rights
Related Party Transaction [Line Items]
Quarterly Distribution Right Held, Percentage	100.00%

Segment_Reporting_Income_state

Segment Reporting - Income statement summary table (Details) (USD $)	1 Months Ended	3 Months Ended
In Thousands, unless otherwise specified	Jan. 28, 2015	Mar. 31, 2015		Mar. 31, 2014		Dec. 31, 2014
	reportable_segment	reportable_segment		Mar. 31, 2014		Dec. 31, 2014
Segment Reporting Information [Line Items]
Number of reportable segments	1	2
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues, net		$70,515		$11,880
Depreciation, accretion and amortization		31,891		3,241
Other operating costs and expenses		50,587		2,500
Interest expense, net		36,855		7,082
Other non-operating expenses		34,887		595
Income tax provision (benefit)		-45	[1]	-457	[1]
Net loss		-83,660		-1,081
Balance Sheet
Total assets		4,365,618	[2]	3,586,420	[2]	3,586,420
Corporate
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues, net		0		0
Depreciation, accretion and amortization		0		0
Other operating costs and expenses		22,567		1,590
Interest expense, net		19,760		527
Other non-operating expenses		26,026		0
Income tax provision (benefit)		-45	[1]	-457	[1]
Net loss		-68,308		-1,660
Balance Sheet
Total assets		171,654	[2]	514,170	[2]
Segments \| Solar Energy
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues, net		48,370		11,880
Depreciation, accretion and amortization		25,755		3,241
Other operating costs and expenses		15,007		910
Interest expense, net		16,338		6,555
Other non-operating expenses		426		595
Income tax provision (benefit)		0	[1]	0	[1]
Net loss		-9,156		579
Balance Sheet
Total assets		3,198,075	[2]	3,072,250	[2]
Segments \| Wind
Segment Reporting Information, Profit (Loss) [Abstract]
Operating revenues, net		22,145	[3]	0
Depreciation, accretion and amortization		6,136	[3]	0
Other operating costs and expenses		13,013	[3]	0
Interest expense, net		757	[3]	0
Other non-operating expenses		8,435	[3]	0
Income tax provision (benefit)		0	[1],[3]	0	[1]
Net loss		-6,196	[3]	0
Balance Sheet
Total assets		$995,889	[2],[3]	$0	[2]

[1]	Income tax benefit is not allocated to the Company's Solar and Wind segments.
[2]	Corporate assets include cash and cash equivalents; other current assets; corporate-level debt and related deferred financing costs, net and other assets.
[3]	Represents the operating results of our wind facilities from January 29, 2015, the date of the acquisition of the First Wind operating portfolio, to MarchB 31, 2015.

Other_Comprehensive_Income_Los2

Other Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, December 31, 2014	($1,637)
Net unrealized losses arising during the period	-5,523
Reclassification of net losses to net income:	2,857
Other comprehensive loss, net of tax	-2,666	0
Accumulated other comprehensive (loss) income	-4,303
Less: other comprehensive loss attributable to non-controlling interests, net of tax	-1,694
Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, March 31, 2015	-2,609
Other comprehensive loss, net of tax:
Foreign currency translation adjustments, before tax	-3,275
Foreign currency translation adjustments, tax effect	0
Foreign currency translation adjustments, net of tax	-3,275	0
Unrealized loss on hedging instruments, before tax	-2,248
Unrealized loss on hedging instruments, tax effect	0
Unrealized loss on hedging instruments, net of tax	-2,248	0
Reclassification, before tax	2,857
Reclassification, tax	0
Reclassification, after tax	2,857	0
Net change, before tax	609
Net change, tax	0
Net change, after tax	609
Other comprehensive loss, before tax	-2,666
Other comprehensive loss, tax effect	0
Other comprehensive loss, net of tax	-2,666	0
Less: other comprehensive loss attributable to non-controlling interests, net of tax	-1,694
Other comprehensive loss attributable to TerraForm Power, Inc. Class A stockholders	-972
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, December 31, 2014	-1,149
Net unrealized losses arising during the period	-3,275
Reclassification of net losses to net income:	0
Other comprehensive loss, net of tax	-3,275
Accumulated other comprehensive (loss) income	-4,424
Less: other comprehensive loss attributable to non-controlling interests, net of tax	-1,862
Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, March 31, 2015	-2,562
Other comprehensive loss, net of tax:
Other comprehensive loss, net of tax	-3,275
Less: other comprehensive loss attributable to non-controlling interests, net of tax	-1,862
Hedging Activities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, December 31, 2014	-488
Net unrealized losses arising during the period	-2,248
Reclassification of net losses to net income:	2,857
Other comprehensive loss, net of tax	609
Accumulated other comprehensive (loss) income	121
Less: other comprehensive loss attributable to non-controlling interests, net of tax	168
Accumulated other comprehensive loss attributable to TerraForm Power, Inc. Class A Stockholders, March 31, 2015	-47
Other comprehensive loss, net of tax:
Other comprehensive loss, net of tax	609
Less: other comprehensive loss attributable to non-controlling interests, net of tax	$168