Via Renewables (VIASP) 10-K 27 Mar 15 2014 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information Document (USD $)	12 Months Ended
	Dec. 31, 2014	Jun. 30, 2014	Mar. 24, 2015
Document and Entity Information [Abstract]
Document Type	10-K
Amendment Flag	FALSE
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Trading Symbol	SPKE
Entity Registrant Name	Spark Energy, Inc.
Entity Central Index Key	1606268
Current Fiscal Year End Date	-19
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Class of Stock [Line Items]
Entity Public Float		$0
Common Class A
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding			3,000,000
Common Class B
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding			10,750,000

COMBINED_AND_CONSOLIDATED_BALA

COMBINED AND CONSOLIDATED BALANCE SHEETS (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$4,359	$7,189
Restricted cash	707	0
Accounts receivable, net of allowance for doubtful accounts of $8.0 million and $1.2 million as of December 31, 2014 and 2013, respectively	63,797	62,678
Accounts receivable-affiliates	1,231	6,794
Inventory	8,032	4,322
Fair value of derivative assets	216	8,071
Customer acquisition costs, net	12,369	4,775
Intangible assets - customer acquisitions, net	486	0
Prepaid assets	1,236	1,032
Deposits	10,569	3,529
Other current assets	2,987	2,901
Total current assets	105,989	101,291
Property and equipment, net	4,221	4,817
Fair value of derivative assets	0	6
Customer acquisition costs	2,976	2,901
Intangible assets - customer acquisitions	1,015	0
Deferred tax assets	24,047	0
Other assets	149	58
Total Assets	138,397	109,073
Current liabilities:
Accounts payable	38,210	36,971
Accounts payable-affiliates	1,017	0
Accrued liabilities	7,195	6,838
Fair value of derivative liabilities	11,526	1,833
Note payable	33,000	27,500
Other current liabilities	1,868	0
Total current liabilities	92,816	73,142
Fair value of derivative liabilities	478	18
Payable pursuant to tax receivable agreement-affiliates	20,767	0
Other long-term liabilities	219	0
Total liabilities	114,280	73,160
Commitments and contingencies (Note 10)
Stockholders' equity:
Member's equity	0	35,913
Preferred stock, par value $0.01 per share, 20,000,000 shares authorized, zero issued and outstanding at December 31, 2014 and zero authorized, issued and outstanding at December 31, 2013	0	0
Additional paid-in capital	9,296	0
Retained deficit	-775	0
Total stockholders' equity	8,659	35,913
Non-controlling interest in Spark HoldCo, LLC	15,458	0
Total equity	24,117	35,913
Total Liabilities and Stockholders' Equity	138,397	109,073
Common Class A
Stockholders' equity:
Common stock	30	0
Common Class B
Stockholders' equity:
Common stock	$108	$0

COMBINED_AND_CONSOLIDATED_BALA1

COMBINED AND CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Allowance for doubtful accounts	$8	$1.20
Preferred stock par value per share	$0.01	$0
Preferred stock shares authorized	20,000,000	0
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common Class A
Common stock par value per share	$0.01	$0
Common stock shares authorized	120,000,000	0
Common stock shares issued	3,000,000	0
Common stock shares outstanding	3,000,000	0
Common Class B
Common stock par value per share	$0.01	$0
Common stock shares authorized	60,000,000	0
Common stock shares issued	10,750,000	0
Common stock shares outstanding	10,750,000	0

COMBINED_AND_CONSOLIDATED_STAT

COMBINED AND CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE (LOSS) INCOME (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenues:
Retail revenues (including retail revenuesbaffiliates of $2,170, $4,022 and $1,382 for the years ended December 31, 2014, 2013 and 2012, respectively)	$320,558	$316,776	$380,198
Net asset optimization revenues (expenses) (including asset optimization revenues-affiliates of $12,842, $14,940 and $8,334 for the years ended December 31, 2014, 2013 and 2012, respectively, and asset optimization revenues affiliates cost of revenues of $30,910, $15,928 and $568 for the years ended December 31, 2014, 2013 and 2012, respectively)	2,318	314	-1,136
Total Revenues	322,876	317,090	379,062
Operating Expenses:
Retail cost of revenues (including retail cost of revenues-affiliates of $13, $55 and $254 for the years December 31, 2014, 2013 and 2012, respectively)	258,616	233,026	279,506
General and administrative (including general and administrative expense-affiliates of less than $100, less than $100 and $800 for the years ended December 31, 2014, 2013 and 2012, respectively)	45,880	35,020	47,321
Depreciation and amortization	22,221	16,215	22,795
Total Operating Expenses	326,717	284,261	349,622
Operating (loss) income	-3,841	32,829	29,440
Other (expense)/income:
Interest expense	-1,578	-1,714	-3,363
Interest and other income	263	353	62
Total other expenses	-1,315	-1,361	-3,301
(Loss) income before income tax expense	-5,156	31,468	26,139
Income tax (benefit) expense	-891	56	46
Net (loss) income	-4,265	31,412	26,093
Less: Net (loss) attributable to non-controlling interests	-4,211	0	0
Net (loss) income attributable to Spark Energy, Inc. stockholders	-54	31,412	26,093
Deferred gain (loss) from cash flow hedges	0	2,620	-10,243
Reclassification of deferred gain (loss) from cash flow hedges into net income (Note 6)	0	-84	17,942
Comprehensive (loss) income	($4,265)	$33,948	$33,792
Net loss attributable to Spark Energy, Inc. per common share
Basic (in dollars per share)	($0.02)
Diluted (in dollars per share)	($0.02)
Weighted average commons shares outstanding
Basic (in shares)	3,000
Diluted (in shares)	3,000

COMBINED_AND_CONSOLIDATED_STAT1

COMBINED AND CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE (LOSS) INCOME (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Optimization Revenues - Affiliates	$2,318,000	$314,000	($1,136,000)
Optimization Cost of Revenues - Affiliates	282,300,000	192,100,000	249,700,000
Retail cost of revenues	258,616,000	233,026,000	279,506,000
General and administrative	45,880,000	35,020,000	47,321,000
Affiliated Entity
Retail Revenues - Affiliates	2,170,000	4,022,000	1,382,000
Optimization Revenues - Affiliates	12,842,000	14,940,000	8,334,000
Optimization Cost of Revenues - Affiliates	30,910,000	15,928,000	568,000
Retail cost of revenues	13,000	55,000	254,000
General and administrative	$100,000	$100,000	$800,000

COMBINED_AND_CONSOLIDATED_STAT2

COMBINED AND CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY (USD $)	Total	Common Class A	Common Class B	Member's Equity	Common Stock	Common Stock	Preferred Stock	Accumulated Other Comprehensive Income	Additional Paid In Capital	Retained Deficit	Total Stockholders Equity	Non-controlling Interest
In Thousands, except Share data, unless otherwise specified	USD ($)			USD ($)	Common Class A	Common Class B		USD ($)	USD ($)	USD ($)	USD ($)	USD ($)
					USD ($)	USD ($)
Stockholders' equity, beginning of period at Dec. 31, 2011	$37,945			$48,180	$0	$0		($10,235)	$0	$0	$0	$0
Shares, beginning of period at Dec. 31, 2011					0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from member	10,060			10,060
Distributions to member	-20,495			-20,495
Net income (loss)	26,093			26,093
Deferred gain (loss) on cash flow hedge derivative instruments	-10,243							-10,243
Reclassification of accumulated OCI net to income	17,942							17,942
Issuance of Class B common stock	0
Consolidated net loss subsequent to the Offering	26,093
Stockholders' equity, end of period at Dec. 31, 2012	61,302			63,838	0	0		-2,536	0	0	0	0
Shares, end of period at Dec. 31, 2012					0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from member	12,400			12,400
Distributions to member	-71,737			-71,737
Net income (loss)	31,412			31,412
Deferred gain (loss) on cash flow hedge derivative instruments	2,620							2,620
Reclassification of accumulated OCI net to income	-84							-84
Issuance of Class B common stock	0
Consolidated net loss subsequent to the Offering	31,412
Stockholders' equity, end of period at Dec. 31, 2013	35,913			35,913	0	0		0	0	0	0	0
Shares, end of period at Dec. 31, 2013					0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital contributions from member	54,201			54,201
Distributions to member	-61,607			-61,607
Net income (loss)	-21			-21
Stockholders' equity, end of period at Jul. 31, 2014	28,486			28,486	0	0		0	0	0	0	0
Shares, end of period at Jul. 31, 2014					0	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of Class B common stock				-28,486		108			28,378		28,486
Issuance of Class B common stock (in shares)						10,750,000
Offering costs paid	-2,667								-2,667		-2,667
Issuance of Class A Common Stock, net of underwriters discount	50,220				30				50,190		50,220
Issuance of common stock (in shares)		3,000,000	10,750,000		3,000,000
Distribution of Offering proceeds and payment of note payable to affiliate	-47,604								-47,604		-47,604
Initial allocation of non-controlling interest of Spark Energy, Inc. effective on date of Offering									-22,232		-22,232	22,232
Tax benefit from tax receivable agreement	23,636								23,636		23,636
Liability due to tax receivable agreement	-20,915								-20,915		-20,915
Stockholders' equity, end of period at Aug. 01, 2014	31,156							0	8,786	0	8,924	22,232
Shares, end of period at Aug. 01, 2014							0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock based compensation	510								510		510
Consolidated net loss subsequent to the Offering	-4,244									-54	-54	-4,190
Distributions paid to Class B non-controlling unit holders	-2,584											-2,584
Dividends paid to Class A common shareholders	-721									-721	-721
Stockholders' equity, end of period at Dec. 31, 2014	$24,117			$0	$30	$108		$0	$9,296	($775)	$8,659	$15,458
Shares, end of period at Dec. 31, 2014					3,000,000	10,750,000	0

COMBINED_AND_CONSOLIDATED_STAT3

COMBINED AND CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net (loss) income	($4,265)	$31,412	$26,093
Adjustments to reconcile net (loss) income to net cash flows provided by operating activities:
Depreciation and amortization expense	22,221	16,215	22,795
Deferred income taxes	-1,064	0	0
Stock based compensation	858	0	0
Amortization and write off of deferred financing costs	631	678	919
Bad debt expense	10,164	3,101	1,835
(Gain) loss on derivatives, net	14,535	-6,567	21,485
Current period cash settlements on derivatives, net	3,479	-1,040	-26,801
Changes in assets and liabilities:
Increase in restricted cash	-707	0	0
(Increase) decrease in accounts receivable	-11,283	6,338	12,019
(Increase) decrease in accounts receivable-affiliates	5,563	13,369	-7,787
(Increase) decrease in inventory	-3,711	-599	3,442
Increase in customer acquisition costs	-26,191	-8,257	-6,322
(Increase) decrease in prepaid and other current assets	-6,905	-1,917	8,505
(Increase) decrease in other assets	-90	144	345
Increase in intangible assets - customer acquisitions	-1,545	0	0
Increase (decrease) in accounts payable and accrued liabilities	1,449	-7,879	-11,394
Increase (decrease) in accounts payable-affiliates	1,017	0	-1,295
Increase (decrease) in other current liabilities	1,867	-518	237
Decrease in other non-current liabilities	-149	0	0
Net cash provided by operating activities	5,874	44,480	44,076
Cash flows from investing activities:
Purchases of property and equipment	-3,040	-1,481	-2,220
Sale of property, plant and equipment-affiliates	0	0	577
Net cash used in investing activities	-3,040	-1,481	-1,643
Cash flows from financing activities:
Borrowings on notes payable	78,500	80,000	39,500
Payments on notes payable	-44,000	-62,500	-68,528
Deferred financing costs	-402	-532	-441
Member contribution (distributions), net	-36,406	-59,337	-10,435
Proceeds from issuance of Class A common stock	50,220	0	0
Distributions of proceeds from Offering to affiliate	-47,554	0	0
Payment of note payable to NuDevco	-50	0	0
Offering costs	-2,667	0	0
Payment of distributions to Class B non-controlling unit holders	-2,584	0	0
Payment of dividends to Class A common shareholders	-721	0	0
Net cash used in financing activities	-5,664	-42,369	-39,904
Decreases in cash and cash equivalents	-2,830	630	2,529
Cash and cash equivalentsbbeginning of period	7,189	6,559	4,030
Cash and cash equivalentsbend of period	4,359	7,189	6,559
Non cash items:
Issuance of Class B common stock	28,486	0	0
Liabilities retained by affiliate	29,000	0	0
Tax benefit from tax receivable agreement	23,636	0	0
Liability due to tax receivable agreement	20,767	0	0
Initial allocation of non-controlling interest	22,232	0	0
Property and equipment purchase accrual	19	0
Interest	860	879	2,686
Taxes	$85	$195	$318

Formation_and_Organization

Formation and Organization	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Formation and Organization	Formation and Organization
	Organization
	Spark Energy, Inc. (the “Company”) is an independent retail energy services company that provides residential and commercial customers in competitive markets across the United States with an alternative choice for natural gas and electricity. The Company is a holding company whose sole material asset consists of units in Spark HoldCo, LLC (“Spark HoldCo”). Spark HoldCo owns all of the outstanding membership interests in each of Spark Energy, LLC (“SE”) and Spark Energy Gas, LLC (“SEG”), the operating subsidiaries through which the Company operates. The Company is the sole managing member of Spark HoldCo, is responsible for all operational, management and administrative decisions relating to Spark HoldCo’s business and consolidates the financial results of Spark HoldCo and its subsidiaries.
	The Company is a Delaware corporation formed on April 22, 2014 by Spark Energy Ventures, LLC (“Spark Energy Ventures”) for the purpose of succeeding to Spark Energy Ventures’ ownership in SE and SEG. Spark Energy Ventures, a single member limited liability company formed on October 8, 2007 under the Texas Limited Liability Company Act (“TLLCA”) is an affiliate of NuDevco Retail Holdings, LLC (“NuDevco Retail Holdings”), a single member Texas limited liability company formed by Spark Energy Ventures on May 19, 2014 under the Texas Business Organizations Code (“TBOC”). NuDevco Retail Holdings was formed by Spark Energy Ventures to hold its investment in Spark HoldCo, LLC, our subsidiary and the direct parent of SEG and SE. NuDevco Retail Holdings is currently a direct wholly owned subsidiary of Spark Energy Ventures, which is wholly owned by NuDevco Partners Holdings, LLC, which is wholly owned by NuDevco Partners, LLC (“NuDevco Partners”), which is wholly owned by W. Keith Maxwell III. NuDevco Retail Holdings formed NuDevco Retail, LLC (“NuDevco Retail” and, together with NuDevco Retail Holdings, “NuDevco”), a single member limited liability company, on May 29, 2014 and it holds a 1% interest in Spark HoldCo formerly held by NuDevco Retail Holdings.
	Prior to the closing of the Company’s initial public offering of 3,000,000 shares of Class A common stock, par value $0.01 per share (the “Class A common stock”), representing a 21.82% interest in the Company, on August 1, 2014 (the “Offering”), Spark Energy Ventures contributed all of its interest in each of SE and SEG to NuDevco Retail Holdings. NuDevco Retail Holdings in turn contributed all of its interest in each of SE and SEG to Spark HoldCo. The contribution of the interests in SE and SEG to Spark HoldCo is not considered a business combination accounted for under the purchase method, as it was a transfer of assets and operations under common control, and accordingly, balances were transferred at their historical cost. The Company’s historical combined financial statements prior to the Offering are prepared using SE’s and SEG’s historical basis in the assets and liabilities, and include all revenues, costs, assets and liabilities attributed to the retail natural gas and asset optimization and retail electricity businesses of SE and SEG.
	SE is a licensed retail electric provider in multiple states. SE provides retail electricity services to end-use retail customers, ranging from residential and small commercial customers to large commercial and industrial users. SE was formed on February 5, 2002 under the Texas Revised Limited Partnership Act (as recodified by the TBOC) and was converted to a Texas limited liability company on May 21, 2014.
	SEG is a retail natural gas provider and asset optimization business competitively serving residential, commercial and industrial customers in multiple states. SEG was formed on January 17, 2001 under the Texas Revised Limited Partnership Act (as recodified by the TBOC) and was converted to a Texas limited liability company on May 21, 2014.
	As a company with less than $1.0 billion in revenues during its last fiscal year, the Company qualifies as an “emerging growth company” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act. An emerging growth company may take advantage of specified reduced reporting and other regulatory requirements.
	The Company will remain an “emerging growth company” for up to five years, or until the earliest of (i) the last day of the fiscal year in which the Company has $1.0 billion or more in annual revenues; (ii) the date on which the Company becomes a “large accelerated filer” (the fiscal year-end on which the total market value of the Company’s common equity securities held by non-affiliates is $700 million or more as of June 30); (iii) the date on which the Company issues more than $1.0 billion of non-convertible debt over a three-year period; or (iv) the last day of the fiscal year following the fifth anniversary of the Offering.
	As a result of the Company's election to avail itself of certain provisions of the JOBS Act, the information that the Company provides may be different than what you may receive from other public companies in which you hold an equity interest.
	Initial Public Offering of Spark Energy, Inc.
	On August 1, 2014, the Company completed the Offering of 3,000,000 shares of its Class A common stock for $18.00 per share, representing a 21.82% voting interest in the Company.
	Net proceeds from the Offering were $47.6 million, after underwriting discounts and commissions, structuring fees and offering expenses. The net proceeds from the Offering were used to acquire units of Spark HoldCo (the “Spark HoldCo units”) representing approximately 21.82% of the outstanding Spark HoldCo units after the Offering from NuDevco Retail Holdings and to repay a promissory note from the Company in the principal amount of $50,000 (the “NuDevco Note”). The Company did not retain any of the net proceeds from the Offering. The Company recorded $2.7 million of previously deferred incremental costs directly attributable to the Offering as a reduction in equity at the Offering date, which were funded by the Offering proceeds.
	The Company also issued 10,750,000 shares of Class B common stock, par value 0.01 per share (the “Class B common stock”) to Spark HoldCo, 10,612,500 of which Spark HoldCo distributed to NuDevco Retail Holdings, and 137,500 of which Spark HoldCo distributed to NuDevco Retail.
	At the consummation of the Offering, the Company's outstanding common stock is summarized in the table below:
			Shares of
			common stock
			Number	Percent Voting Interest
	Publicly held Class A common stock		3,000,000	21.82	%
	Class B common stock held by NuDevco Retail Holdings, LLC and NuDevco Retail, LLC		10,750,000	78.18	%
	Total		13,750,000	100	%
	Credit Facility
	Concurrently with the closing of the Offering, the Company entered into a new $70.0 million senior secured credit facility (“Senior Credit Facility”). See Note 4 “Long-Term Debt” for further discussion.
	Exchange and Registration Rights
	NuDevco has the right to exchange (the “Exchange Right”) all or a portion of its Spark HoldCo units (together with a corresponding number of shares of Class B common stock) for Class A common stock (or cash at Spark Energy, Inc.’s or Spark HoldCo’s election (the “Cash Option”)) at an exchange ratio of one share of Class A common stock for each Spark HoldCo unit (and corresponding share of Class B common stock) exchanged. In addition, NuDevco has the right, under certain circumstances, to cause the Company to register the offer and resale of NuDevco's shares of Class A common stock obtained pursuant to the Exchange Right.
	Tax Receivable Agreement
	Concurrently with the closing of the Offering, the Company entered into a Tax Receivable Agreement with Spark HoldCo, NuDevco Retail Holdings and NuDevco Retail. See Note 11 “Transactions with Affiliates” for further discussion.
	Other Transactions in Connection with the Consummation of the Offering
	In connection with the Offering the following restructuring transactions occurred:
	•	SEG and SE were converted from limited partnerships into limited liability companies;
	•	SEG, SE and an affiliate entered into an interborrower agreement, pursuant to which such affiliate agreed to be solely responsible for $29.0 million of the outstanding indebtedness. SE and SEG repaid their outstanding indebtedness of $10.0 million and borrowed $10.0 million under the Company's Senior Credit Facility,
	•	NuDevco Retail Holdings contributed all of its interests in SEG and SE to Spark HoldCo in exchange for all of the outstanding units of Spark HoldCo and transferred 1% of those Spark HoldCo units to NuDevco Retail;
	•	NuDevco Retail Holdings transferred Spark HoldCo units to the Company for the $50,000 NuDevco Note and the limited liability company agreement of Spark HoldCo was amended and restated to admit the Company as its sole managing member.
	Following the Offering, the Company purchased 2,997,222 Spark HoldCo units from NuDevco Retail Holdings and repaid the NuDevco Note. The 2,997,222 Spark Holdco units we purchased with the proceeds from the Offering, together with the 2,778 Spark HoldCo units we purchased in exchange for the NuDevco Note prior to the Offering, represent a 21.82% ownership interest in Spark HoldCo. After giving effect to these transactions and the Offering, the Company owns an approximate 21.82% interest in Spark HoldCo. NuDevco Retail Holdings owns an approximate 77.18% interest in Spark HoldCo and 10,612,500 shares of Class B common stock, and NuDevco Retail owns a 1% interest in Spark HoldCo and 137,500 shares of Class B common stock.
	Each share of Class B common stock, all of which is held by NuDevco, has no economic rights but entitles its holder to one vote on all matters to be voted on by shareholders generally. Holders of Class A common stock and Class B common stock vote together as a single class on all matters presented to our shareholders for their vote or approval, except as otherwise required by applicable law or by our certificate of incorporation.

Basis_of_Presentation_and_Summ

Basis of Presentation and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies
	The accompanying combined and consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). All significant intercompany transactions and balances have been eliminated in the combined and consolidated financial statements.
	The accompanying combined and consolidated financial statements have been prepared in accordance with Regulation S-X, Article 3, General Instructions as to Financial Statements and Staff Accounting Bulletin (“SAB”) Topic 1-B, Allocations of Expenses and Related Disclosures in Financial Statements of Subsidiaries, Divisions or Lesser Business Components of Another Entity on a stand-alone basis and are derived from SE’s and SEG’s historical basis in the assets and liabilities before the Offering and Spark Energy Inc.’s financial results after the Offering, and include all revenues, costs, assets and liabilities attributable to the retail natural gas and asset optimization and retail electricity businesses of SE and SEG for the periods prior to the Offering that are specifically identifiable or have been allocated to the Company. Management has made certain assumptions and estimates in order to allocate a reasonable share of expenses to the Company, such that the Company’s combined and consolidated financial statements reflect substantially all of its costs of doing business. The Company also enters into transactions with and pays certain costs on behalf of affiliates under common control in order to reduce risk, reduce administrative expense, create economies of scale, create strategic alliances and supply goods and services to these related parties. The Company direct bills certain expenses incurred on behalf of affiliates or allocates certain overhead expenses to affiliates associated with general and administrative services based on services provided, departmental usage, or headcount, which are considered reasonable by management. The allocations and related estimates and assumptions are described more fully in Note 11 “Transactions with Affiliates”. These costs are not necessarily indicative of the cost that the Company would have incurred had it operated as an independent stand-alone entity prior to the Offering. Affiliates have also relied upon Spark Energy Ventures as a participant in the credit facility for periods prior to the Offering as described more fully in Note 4 “Long-Term Debt”. As such, the Company’s combined and consolidated financial statements do not fully reflect what the Company’s financial position, results of operations and cash flows would have been had the Company operated as an independent stand-alone company prior to the Offering. As a result, historical financial information prior to the Offering is not necessarily indicative of what the Company’s results of operations, financial position and cash flows will be in the future. The Company’s combined and consolidated financial statements include all wholly-owned and controlled subsidiaries.
	Cash and Cash Equivalents
	Cash and cash equivalents consist of all unrestricted demand deposits and funds invested in highly liquid instruments with original maturities of three months or less. The Company periodically assesses the financial condition of the institutions where these funds are held and believes that its credit risk is minimal with respect to these institutions.
	Restricted Cash
	Restricted cash consists of cash that has been placed in escrow for a contractually designated future use. As of December 31, 2014, the Company had $0.7 million in restricted cash related to future required payments for customer acquisitions as described in more detail in Note 13 “Customer Acquisitions”. The restricted cash is classified as current as the payments for these customers are expected to be made in the first quarter of 2015. There was no restricted cash as of December 31, 2013.
	Accounts Receivable
	Trade accounts receivable are recorded at the invoiced amount and do not bear interest. Accounts receivable in the combined and consolidated balance sheets are net of allowance for doubtful accounts of $8.0 million and $1.2 million as of December 31, 2014 and 2013, respectively.
	The Company accrues an allowance for doubtful accounts based upon estimated uncollectible accounts receivable considering historical collections, accounts receivable aging analysis, credit risk and other factors. The Company writes off accounts receivable balances against the allowance for doubtful accounts when the accounts receivable is deemed to be uncollectible. Bad debt expense of $10.2 million, $3.1 million and $1.8 million was recorded in general and administrative expense in the combined and consolidated statements of operations for the years ended December 31, 2014, 2013 and 2012, respectively.
	The Company conducts business in many utility service markets where the local regulated utility is responsible for billing the customer, collecting payment from the customer and remitting payment to the Company (“POR programs”). This POR service results in substantially all of the Company’s credit risk being linked to the applicable utility, which generally has an investment-grade rating, and not to the end-use customer. The Company monitors the financial condition of each utility and currently believes that its susceptibility to an individually significant write-off as a result of concentrations of customer accounts receivable with those utilities is remote. Trade accounts receivable that are part of a local regulated utility’s POR program are recorded on a gross basis in accounts receivable in the combined and consolidated balance sheets. The discount paid to the local regulated utilities is recorded in general and administrative expense in the combined and consolidated statements of operations.
	In markets that do not offer POR services or when the Company chooses to directly bill its customers, certain receivables are billed and collected by the Company. The Company bears the credit risk on these accounts and records an appropriate allowance for doubtful accounts to reflect any losses due to non-payment by customers. The Company’s customers are individually insignificant and geographically dispersed in these markets. The Company writes off customer balances when it believes that amounts are no longer collectible and when it has exhausted all means to collect these receivables.
	Inventory
	Inventory consists of natural gas used to fulfill and manage seasonality for fixed and variable-price retail customer load requirements and is valued at the lower of weighted average cost or market. Purchased natural gas costs are recognized in the combined and consolidated statements of operations, within retail cost of revenues, when the natural gas is sold and delivered out of the storage facility. There were no inventory impairments recorded for the years ended December 31, 2014, 2013 and 2012. When natural gas is sold costs are recognized in the combined and consolidated statements of operations, within retail cost of revenues, at the weighted average cost value at the time of the sale.
	Customer Acquisition Costs
	The Company has retail natural gas and electricity customer acquisition costs, net of $12.4 million and $4.8 million recorded in current assets and $3.0 million and $2.9 million recorded in noncurrent assets representing direct response advertising costs as of December 31, 2014 and 2013, respectively. Customer acquisition costs is spending for organic customer acquisitions and does not include customer acquisitions through merger and acquisition activities, which are recorded as intangible assets. Amortization of customer acquisition costs, recorded in depreciation and amortization in the combined and consolidated statements of operations, was $18.5 million, $10.1 million and $16.4 million for the years ended December 31, 2014, 2013 and 2012, respectively. Capitalized direct response advertising costs consist primarily of hourly and commission based telemarketing costs, door-to-door agent commissions and other direct advertising costs associated with proven customer generation, and are capitalized and amortized over the estimated two-year average life of a customer in accordance with the provisions of FASB ASC 340-20, Capitalized Advertising Costs.
	Recoverability of customer acquisition costs is evaluated based on a comparison of the carrying amount of the customer acquisition costs to the future net cash flows expected to be generated by the customers acquired, considering specific assumptions for customer attrition, per unit gross profit, and operating costs. These assumptions are based on forecasts and historical experience.
	Based on the analysis described above, for the year ended December 31, 2014, the Company recorded accelerated amortization of such costs of $6.5 million associated with capitalized customer acquisition costs in California and $0.2 million associated with capitalized customer acquisition costs in Massachusetts. This accelerated amortization expense is included in “depreciation and amortization” on the statement of operations. There were no such accelerated amortization charges recorded for the year ended December 31, 2013 and 2012.
	Intangibles - Customer Acquisitions
	Customer acquisitions through merger and acquisition activities are recorded as intangible assets and represent customer contract acquisitions not acquired through the direct response advertising discussed above at “Customer Acquisition Costs”. The Company has recorded $1.5 million, net of amortization, as of December 31, 2014 related to these intangible assets. These intangibles are amortized over the estimated three-year average life of the related customer contracts acquired.
	We review intangible assets for impairment whenever events or changes in business circumstances indicate the carrying value of the intangible assets may not be recoverable. Impairment is indicated when the undiscounted cash flows estimated to be generated by the intangible assets are less than their respective carrying value. If an impairment exists, a loss would be recognized for the difference between the fair value and carrying value of the intangible assets. No impairments of intangible assets were recorded in 2014, 2013 and 2012.
	Deferred Financing Costs
	Costs incurred in connection with the issuance of long-term debt are capitalized and amortized to interest expense using the straight-line method over the life of the related long-term debt due to the variable nature of the Company’s long-term debt.
	Property and Equipment
	The Company records property and equipment at historical cost. Depreciation expense is recorded on a straight-line method based on estimated useful lives. When assets are placed into service, management makes estimates with respect to useful lives and salvage values of the assets.
	When items of property and equipment are sold or otherwise disposed of, any gain or loss is recorded in the combined and consolidated statements of operations.
	The Company capitalizes costs associated with internal-use software projects in accordance with FASB ASC Topic 350-40, Internal-Use Software. Capitalized costs are the costs incurred during the application development stage of the internal-use software project such as software configuration, coding, installation of hardware and testing. Costs incurred during the preliminary or post-implementation stage of the internal-use software project are expensed in the period incurred. These types of costs include formulation of ideas and alternatives, training and application maintenance. After internal-use software projects are completed, the associated capitalized costs are depreciated over the estimated useful life of the related asset. Interest costs incurred while developing internal-use software projects are capitalized in accordance with FASB ASC Topic 835-20, Capitalization of Interest. Capitalized interest costs for the years ended December 31, 2014, 2013 and 2012 were not material.
	Segment Reporting
	The FASB ASC Topic 280, Segment Reporting, established standards for entities to report information about the operating segments and geographic areas in which they operate. The Company operates two segments, retail natural gas and retail electricity, and all of its operations are located in the United States.
	Revenues and Cost of Revenues
	The Company’s revenues are derived primarily from the sale of natural gas and electricity to retail customers. The company also records revenue from sales of natural gas and electricity to wholesale counterparties, including affiliates. Revenues are recognized by the Company using the following criteria: (1) persuasive evidence of an exchange arrangement exists, (2) delivery has occurred or services have been rendered, (3) the buyer’s price is fixed or determinable and (4) collection is reasonably assured. Utilizing these criteria, revenue is recognized when the natural gas or electricity is delivered. Similarly, cost of revenues is recognized when the commodity is delivered.
	Revenues for natural gas and electricity sales are recognized upon delivery under the accrual method. Natural gas and electricity sales that have been delivered but not billed by period end are estimated. Accrued unbilled revenues are based on estimates of customer usage since the date of the last meter read provided by the utility. Volume estimates are based on forecasted volumes and estimated customer usage by class. Unbilled revenues are calculated by multiplying these volume estimates by the applicable rate by customer class. Estimated amounts are adjusted when actual usage is known and billed.
	The Company records gross receipts taxes on a gross basis in retail revenues and retail cost of revenues. During the years ended December 31, 2014, 2013 and 2012, the Company’s retail revenues and retail cost of revenues included gross receipts taxes of $3.0 million, $3.5 million and $5.1 million, respectively.
	Costs for natural gas and electricity sales are recognized as the commodity is delivered to the customer under the accrual method. Natural gas and electricity costs that have not been billed to the Company by suppliers but have been incurred by period end are estimated. The Company estimates volumes for natural gas and electricity delivered based on the forecasted revenue volumes, estimated transportation cost volumes and estimation of other costs associated with retail load which varies by commodity utility territory. These costs include items like ISO fees, ancillary services and renewable energy credits. Estimated amounts are adjusted when actual usage is known and billed.
	The Company’s asset optimization activities, which primarily include natural gas physical arbitrage and other short term storage and transportation opportunities, meet the definition of trading activities and are recorded on a net basis in the combined and consolidated statements of operations in net asset optimization revenues pursuant to FASB ASC 815, Derivatives and Hedging. The Company recorded asset optimization revenues, primarily related to physical sales or purchases of commodities, of $284.6 million, $192.4 million and $248.6 million for the years ended December 31, 2014, 2013 and 2012, respectively, and recorded asset optimization costs of revenues of $282.3 million, $192.1 million and $249.7 million for the years ended December 31, 2014, 2013 and 2012, respectively, which are presented on a net basis in asset optimization revenues.
	Natural Gas Imbalances
	The combined and consolidated balance sheets include natural gas imbalance receivables and payables, which primarily results when customers consume more or less gas than has been delivered by the Company to local distribution companies (“LDCs”). The settlement of natural gas imbalances varies by LDC, but typically the natural gas imbalances are settled in cash or in kind on a monthly, quarterly, semi-annual or annual basis. The imbalances are valued at an estimated net realizable value. The Company recorded an imbalance receivable of $1.4 million and $0.7 million recorded in other current assets on the combined and consolidated balance sheets as of December 31, 2014 and 2013, respectively. The Company recorded an imbalance payable of $0.6 million and zero recorded in other current liabilities on the combined and consolidated balance sheets as of December 31, 2014 and 2013, respectively.
	Fair Value
	FASB ASC 820, Fair Value Measurement, established a single authoritative definition of fair value, set out a framework for measuring fair value, and requires disclosures about fair value measurements. The standard clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. The standard utilizes a fair value hierarchy that prioritizes the inputs to the valuation techniques used to measure fair value into three broad levels based on quoted prices in active market, observable market prices, and unobservable market prices.
	When the Company is required to measure fair value, and there is not a quoted or observable market price for a similar asset or liability, the Company utilizes the cost, income, or market valuation approach depending on the quality of information available to support management’s assumptions.
	Derivative Instruments
	The Company uses derivative instruments such as futures, swaps, forwards and options to manage the commodity price risks of its business operations.
	All derivatives, other than those for which an exception applies, are recorded in the combined and consolidated balance sheets at fair value. Derivative instruments representing unrealized gains are reported as derivative assets while derivative instruments representing unrealized losses are reported as derivative liabilities. The Company has elected to offset amounts in the combined and consolidated balance sheets for derivative instruments executed with the same counterparty under a master netting arrangement. One of the exceptions to fair value accounting, normal purchases and normal sales, has been elected by the Company for certain derivative instruments when the contract satisfies certain criteria, including a requirement that physical delivery of the underlying commodity is probable and is expected to be used in normal course of business. Retail revenues and retail cost of revenues resulting from deliveries of commodities under normal purchase contracts and normal sales contracts are included in earnings at the time of contract settlement.
	To manage commodity price risk, the Company holds certain derivative instruments that are not held for trading purposes and are not designated as hedges for accounting purposes. However, to the extent the Company does not hold offsetting positions for such derivatives, they believe these instruments represent economic hedges that mitigate their exposure to fluctuations in commodity prices. As part of the Company’s strategy to optimize its assets and manage related commodity risks, it also manages a portfolio of commodity derivative instruments held for trading purposes. The Company uses established policies and procedures to manage the risks associated with price fluctuations in these energy commodities and uses derivative instruments to reduce risk by generally creating offsetting market positions.
	Changes in the fair value of and amounts realized upon settlement of derivative instruments not held for trading purposes are recognized currently in earnings in retail revenues or retail costs of revenues, respectively.
	Changes in the fair value of and amounts realized upon settlement of derivative instruments held for trading purposes are recognized currently in earnings in net asset optimization revenues.
	The Company has historically designated a portion of our derivative instruments as cash flow hedges for accounting purposes. For all hedging transactions, the Company formally documented the hedging transaction and its risk management objective and strategy for undertaking the hedge, the hedging instrument, the nature of the risk being hedged, how the hedging instrument’s effectiveness in offsetting the hedged risk was assessed prospectively and retrospectively, and a description of the method used to measure ineffectiveness. The Company also formally assessed, both at the inception of the hedging transaction and on an ongoing basis, whether the derivatives used in hedging transactions were highly effective in offsetting changes in cash flows of hedged transactions. For derivative instruments that were designated and qualified as part of a cash flow hedging transaction, the effective portion of the gain or loss on the derivative was reported as a component of other comprehensive income and reclassified into earnings in the same period or periods during when the hedged transaction affected earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness were recognized in current earnings. Hedge accounting was discontinued prospectively for derivatives that ceased to be highly effective hedges or when the occurrence of the forecasted transaction was no longer probable.
	Effective July 1, 2013, the Company elected to discontinue hedge accounting prospectively and began to record the changes in fair value recognized in the combined and consolidated statement of operations in the period of change. Because the underlying transactions were still probable of occurring, the related accumulated OCI was frozen and recognized in earnings as the underlying hedged item was delivered. As of December 31, 2014 and 2013, the Company has no gains or losses on derivatives that were designated as qualifying cash flow hedging transactions recorded as a component of accumulated OCI, as all previously deferred gains and losses on qualifying hedge transactions were reclassified into earnings during the year ended December 31, 2013 and 2012 when the associated hedged transactions were recorded into earnings.
	Income Taxes
	The Company recognizes the amount of taxes payable or refundable for the year. In addition, the Company follows the asset and liability method of accounting for income taxes where deferred tax assets and liabilities are recognized for the expected future tax consequences of events that have been recognized in the financial statements or tax returns and operating loss carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in those years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in the tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is provided for deferred tax assets if it is more likely than not that these items will not be realized.
	In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the projected future taxable income and tax planning strategies in making this assessment. Based upon the level of historical taxable income and projections for future taxable income over the periods in which the deferred tax assets are deductible, management believes it is more likely than not that we will realize the benefits of these deductible differences.
	The Company recognizes interest and penalties related to unrecognized tax benefits within the provision for income taxes on continuing operations in our consolidated statements of operations.
	Earnings per Share
	Basic earnings per share (“EPS”) is computed by dividing net income attributable to shareholders (the numerator) by the weighted-average number of Class A common shares outstanding for the period (the denominator). Class B common shares are not included in the calculation of basic earnings per share because they have no economic interest in the Company. Diluted earnings per share is similarly calculated except that the denominator is increased (1) using the treasury stock method to determine the potential dilutive effect of the Company’s outstanding unvested restricted stock units and (2) using the if-converted method to determine the potential dilutive effect of the Company’s Class B common stock. The Company has omitted earnings per share prior to the Offering because the Company operated under a sole member equity structure for those periods.
	Non-controlling Interest
	As a result of the Offering, the Company acquired a 21.82% economic interest in Spark HoldCo, and is the sole managing member in Spark HoldCo, with NuDevco Retail Holdings, LLC and NuDevco Retail, LLC (collectively, “NuDevco”) retaining a 78.18% economic interest in Spark HoldCo. As a result, the Company has consolidated the financial position and results of operations of Spark HoldCo and reflected the economic interest retained by NuDevco as a non-controlling interest. Net income attributable to non-controlling interest for the year ended December 31, 2014 represents the net income attributable to NuDevco prior to the Offering and NuDevco’s retained interest subsequent to the Offering.
	Commitments and Contingencies
	The Company enters into various firm purchase and sale commitments for natural gas, storage, transportation, and electricity that do not meet the definition of a derivative instrument or for which the Company has elected the normal purchase or normal sales exception. Management does not anticipate that such commitments will result in any significant gains or losses based on current market conditions.
	Liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred.
	Transactions with Affiliates
	The Company enters into transactions with and incurs certain costs on behalf of affiliates that are commonly controlled by NuDevco Partners Holdings in order to reduce risk, reduce administrative expense, create economies of scale, create strategic alliances and supply goods and services to these related parties. These transactions include, but are not limited to, certain services to the affiliated companies associated with the Company’s debt facility prior to the Offering, employee benefits provided through the Company’s benefit plans, insurance plans, leased office space, and administrative salaries for accounting, tax, legal, or technology services. As such, the accompanying combined and consolidated financial statements include costs that have been incurred by the Company and then directly billed or allocated to affiliates and are recorded net in general and administrative expense on the combined and consolidated statements of operations with a corresponding accounts receivable-affiliates recorded in the combined and consolidated balance sheets. Additionally, the Company enters into transactions with certain affiliates for sales or purchases of natural gas and electricity, which are recorded in retail revenues, retail cost of revenues, and net asset optimization revenues in the combined and consolidated statements of operations with a corresponding accounts receivable-affiliate or accounts payable-affiliate in the combined and consolidated balance sheets. See Note 11, “Transactions with Affiliates” for further discussion.
	Use of Estimates and Assumptions
	The preparation of the Company’s combined and consolidated financial statements requires estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the combined financial statements and the reported amounts of revenues and expenses during the period. Actual results could materially differ from those estimates. Significant items subject to such estimates by the Company’s management include estimates for unbilled revenues and related cost of revenues, provisions for uncollectible receivables, valuation of customer acquisition costs, estimated useful lives of property and equipment, valuation of derivatives and reserves for contingencies.
	Subsequent Events
Subsequent events have been evaluated through the date these financial statements are issued. Any material subsequent events that occurred prior to such date have been properly recognized or disclosed in the combined and consolidated financial statements. See Note 14 “Subsequent Events” for further discussion.
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. ASU 2014-09 will replace most existing revenue recognition guidance in GAAP when it becomes effective on January 1, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.
In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). The new guidance clarifies management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosure. ASU 2014-15 is effective for annual periods ending after December 15, 2016 and for annual periods and interim periods thereafter. Early adoption is permitted. The Company does not expect the adoption to have a material effect on the combined or consolidated financial statements.
In November 2014, the FASB issued ASU No. 2014-16, Derivatives and Hedging, which clarifies how current GAAP should be interpreted in evaluating the economic characteristics and risks of a host contract in a hybrid financial instrument that is issued in the form of a share. The amendments in this Update are effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption, including adoption in an interim period, is permitted. The Update does not change the current criteria in GAAP for determining when separation of certain embedded derivative features in a hybrid financial instrument is required. The Company does not believe the adoption of this ASU to have a material impact on the combined and consolidated financial statements.
In February 2015, the FASB issued ASU No. 2015-02, Consolidation (Topic 810) (“ASU 2015-02”). The new guidance changes the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. ASU 2015-02 is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted, including adoption at an interim period. The Company has not yet determined the effect of the standard on its ongoing financial reporting.

Property_and_Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment
	Property and equipment consist of the following amounts as of (in thousands):
		Estimated	31-Dec-14			31-Dec-13
		useful
		lives (years)
	Information technology	2 – 5	$	25,588		$	22,529
	Leasehold improvements	2 – 5	4,568			4,568
	Furniture and fixtures	2 – 5	998			998
	Total		31,154			28,095
	Accumulated depreciation		(26,933		)	(23,278		)
	Property and equipment—net		$	4,221		$	4,817
	Information technology assets include software and consultant time used in the application, development and implementation of various systems including customer billing and resource management systems. As of December 31, 2014 and 2013, information technology includes $0.4 million and $1.3 million, respectively, of costs associated with assets not yet placed into service.
	Depreciation expense recorded in the combined and consolidated statements of operations was $3.7 million, $6.1 million and $6.4 million for the years ended December 31, 2014, 2013 and 2012, respectively.

LongTerm_Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2014
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt
	In October 2007, Spark Energy Ventures and all of its subsidiaries (collectively, the “Borrowers”), entered into a credit agreement, consisting of a working capital facility, a term loan and a revolving credit facility (the “Credit Agreement”), with SE and SEG as co-borrowers under which they were jointly and severally liable for amounts Borrowers borrowed under the Credit Agreement. The Credit Agreement was secured by substantially all of the assets of Spark Energy Ventures and its subsidiaries.
	The Credit Agreement was amended on May 30, 2008 to provide for a $177.5 million working capital facility, a $100 million term loan, and a $35 million revolving credit facility. On January 24, 2011, the Borrowers amended and restated the Credit Agreement (the “Fifth Amended Credit Agreement”) to decrease the working capital facility to $150 million, to increase the term loan to $130 million and to eliminate the revolving credit facility.
	On December 17, 2012, the Borrowers amended and restated the Fifth Amended Credit Agreement to decrease the working capital facility to $70 million, to decrease the term loan to $125 million and to reinstate the revolving credit facility in the amount of $30 million (the “Sixth Amended Credit Agreement”).
	On July 31, 2013 and in conjunction with the initial public offering of Marlin Midstream Partners, LP (“Marlin”), which was formerly a wholly owned subsidiary of Spark Energy Ventures, the Sixth Amended Credit Agreement was amended and restated to increase the working capital facility to $80 million and eliminate the term loan and revolving credit facility (the “Seventh Amended Credit Agreement”) and to remove Marlin as a party to the Credit Agreement. The Seventh Amended Credit Agreement continued to be secured by the assets of Spark Energy Ventures and its subsidiaries through completion of the Offering.
	Although SE and SEG, as wholly owned subsidiaries of Spark Energy Ventures, were jointly and severally liable for Marlin’s borrowing under the Sixth Amended Credit Agreement prior to the Marlin initial public offering, SE and SEG did not historically have access to or use the term loan and the revolving credit facility utilized by Marlin. SE and SEG were the primary recipients of the proceeds from the working capital facility.
	The Company adopted ASU 2013-04, which prescribes the accounting for joint and several liability arrangements early and applied the accounting in the guidance combined and consolidated financial statements prior to the Offering as required by the standard. This guidance requires an entity to measure its obligation resulting from joint and several liability arrangements for which the total amount under the arrangement is fixed at the reporting date, as the sum of the amount the reporting entity agreed to pay on the basis of its arrangement among its co-obligors and any additional amount the reporting entity expects to pay on behalf of its co-obligors. Based on the Sixth Amended Credit Agreement prior to the Marlin initial public offering and understanding among the Borrowers, the term loan and the revolving credit facility were assigned specifically to Marlin. The Company has recognized the proceeds from the working capital facility in its combined financial statements prior to the Offering, which represented the amounts the Company with the other Borrowers agreed to pay, and the amounts the Company expected to pay.
	Working Capital Facility
	The working capital facility was $150 million in 2012 under the Fifth Amended Credit Agreement and was later amended to $70 million on December 17, 2012 under the Sixth Amended Credit Agreement. On July 31, 2013, and in conjunction with the Seventh Amended Credit Agreement, the working capital facility was increased to $80 million.
	The working capital facility was available for use by Spark Energy Ventures and its affiliates to finance the working capital requirements related to the purchase and sale of natural gas, electricity, and other commodity products not related to the retail natural gas and asset optimization and retail electricity businesses of the Company. The Company’s combined financial statements include the total amounts outstanding under the working capital facility of $27.5 million as of December 31, 2013, which is classified as current in the combined and consolidated balance sheet as the working capital facility was drawn upon and repaid on a monthly basis to fund working capital needs. Portions of the borrowings were used to fund equity distributions to the sole member of the Company to fund unrelated operations of an affiliate under the common control of the sole member prior to the Offering. The total amounts outstanding under the facility as of December 31, 2013 and through the Offering date included $29.0 million that was retained and paid off by an affiliate in connection with the Offering.
	Further, through the issuance of letters of credit, the Company was able to secure payment to suppliers. No obligation is recorded for such outstanding letters of credit unless they are drawn upon by the suppliers and in the event a supplier draws on a letter of credit, repayment is due by the earlier of demand by the bank or at the expiration of the applicable Credit Agreement. Letters of credit issued and outstanding as of December 31, 2013 were $10.0 million.
	Under the working capital facility, the Company paid a fee with respect to each letter of credit issued and outstanding. For the years ended December 31, 2014, 2013 and 2012, the Company incurred fees on letters of credit issued and outstanding totaling $0.4 million, $0.5 million and $0.6 million, respectively, which is recorded in interest expense in the combined and consolidated statements of operations.
	Under the Sixth Amended Credit Agreement, the Company was able to elect to have loans under the working credit facility bear interest either (i) at a Eurodollar-based rate plus a margin ranging from 3.00% to 3.75% depending on the Company’s consolidated funded indebtedness ratio then in effect, or (ii) at a base rate loan plus a margin ranging from 2.00% to 2.75% depending on the Company’s consolidated funded indebtedness ratio then in effect. The Company also paid a nonutilization fee equal to 0.50% per annum.
	Under the Seventh Amended Credit Agreement, the Company was able to elect to have loans under the working capital facility bear interest (i) at a Eurodollar-based rate plus a margin ranging from 3.00% to 3.25%, depending on the Spark Energy Ventures’ aggregate amount outstanding then in effect, (ii) at a base rate loan plus a margin ranging from 2.00% to 2.25%, depending on Spark Energy Ventures’ aggregate amount outstanding then in effect or (iii) a cost of funds rate loan plus a margin ranging from 2.50% to 2.75%, depending on Spark Energy Ventures’ aggregate amount outstanding then in effect. Each working capital loan made as a result of a drawing under a letter of credit bears interest on the outstanding principal amount thereof from the date funded at a floating rate per annum equal to the cost of funds rate plus the applicable margin until such loan has been outstanding for more than two business days and, thereafter, bears interest on the outstanding principal amount thereof at a floating rate per annum equal to the base rate plus the applicable margin, plus two percent 2.00% per annum. The Company incurred interest expense related to our revolving credit facilities of $0.4 million, $0.3 million and $1.3 million for the years ended December 31, 2014, 2013 and 2012, respectively, which is recorded in interest expense in the combined and consolidated statements of operations.
	The Company also paid a commitment fee equal to 0.50% per annum. The Company incurred commitment fees from the prior and current facilities totaling $0.1 million, $0.2 million and $0.5 million for the years ended December 31, 2014, 2013 and 2012, which is recorded in interest expense in the combined and consolidated statements of operations.
	Deferred Financing Costs
	Deferred financing costs were $0.3 million (all of which represents capitalized financing costs related to the new Senior Credit Facility entered into on August 1, 2014) and $0.5 million as of December 31, 2014 and 2013, respectively. Of these amounts, $0.2 million and $0.4 million is recorded in other current assets in the combined and consolidated balance sheets as of December 31, 2014 and 2013, respectively, and $0.1 million and $0.1 million is recorded in other assets in the combined and consolidated balance sheets as of December 31, 2014 and 2013, respectively, based on the terms of the working capital facilities.
	Amortization and write offs of deferred financing costs were $0.6 million (which included $0.3 million of deferred financing costs written off upon extinguishment of the Seventh Amended Credit Facility), $0.7 million (which included $0.1 million of deferred financing costs written off in connection with the execution of the Seventh Amended Credit Facility), and $0.9 million (which included $0.3 million of deferred financing costs written off in connection with the execution of the Sixth Amended Credit Facility), for the years ended December 31, 2014, 2013 and 2012, respectively, which is recorded in interest expense in the combined and consolidated statements of operations.
	NuDevco Note
	NuDevco Retail Holdings transferred Spark HoldCo units to the Company for the $50,000 NuDevco Note, and the limited liability company agreement of Spark HoldCo was amended and restated to admit Spark Energy, Inc. as its sole managing member. This promissory note was repaid in connection with proceeds from the Offering.
	New Credit Facility
	Concurrently with the closing of the Offering, the Company entered into the $70.0 million Senior Credit Facility, which matures on August 1, 2016. If no event of default has occurred, the Company has the right, subject to approval by the administrative agent and each issuing bank, to increase the commitments under the Senior Credit Facility up to $120.0 million. The Company borrowed approximately $10.0 million under the Senior Credit Facility at the closing of the Offering to repay in full the outstanding indebtedness under the Seventh Amended Credit Agreement that SEG and SE agreed to be responsible for pursuant to an interborrower agreement between SEG, SE and an affiliate. The remaining $29.0 million of indebtedness outstanding under the Seventh Amended Credit Agreement at the Offering date was paid down by our affiliate with its own funds concurrent with the closing of the Offering pursuant to the terms of the interborrower agreement. Following this repayment, the Seventh Amended Credit Agreement was terminated. The Company had $15 million in letters of credit issued under the Senior Credit Facility at inception. As of December 31, 2014, the Company had $33.0 million outstanding under the Senior Credit Facility and $10.7 million in letters of credit issued. The Senior Credit Facility is available to fund expansions, acquisitions and working capital requirements for operations and general corporate purposes.
	At our election, interest under the Senior Credit Facility is generally determined by reference to:
	•	the Eurodollar-based rate plus a margin ranging from 2.75% to 3.00%, depending on the overall utilization of the working capital facility;
	•	the alternate base rate loan plus a margin ranging from 1.75% to 2.00%, depending on the overall utilization of the working capital facility; or
	•	a cost of funds rate loan plus a margin ranging from 2.25% to 2.50%, depending on the overall utilization of the working capital facility.
	The interest rate is generally reduced by 25 basis points if utilization under the Senior Credit Facility is below fifty percent.
	Each working capital loan made as a result of a drawing under a letter of credit or a reducing letter of credit borrowing bears interest on the outstanding principal amount thereof from the date funded at a floating rate per annum equal to the base rate plus the applicable margin until such loan has been outstanding for more than two business days and, thereafter, bears interest on the outstanding principal amount thereof at a floating rate per annum equal to the base rate plus the applicable margin, plus two percent (2.00%) per annum. Additionally, the Company is charged a letter of credit fee for letters of credit outstanding. Our fee is from 2.00% to 2.50% per annum, depending on the overall utilization of the working capital facility and what type of transaction it supports.
	We pay an annual commitment fee of 0.375% or 0.5% on the unused portion of the Senior Credit Facility depending upon the unused capacity. The lending syndicate under the Senior Credit Facility is entitled to several additional fees including an upfront fee, annual agency fee, and fronting fees based on a percentage of the face amount of letters of credit payable to any syndicate member that issues a letter a credit. Commitment fees were immaterial for the year ended December 31, 2014. The Company paid no commitment fees related to the Senior Credit Facility for the years ended December 31, 2013 and 2012.
	The Company incurred total interest expense related to prior and current credit facilities of $1.6 million, $1.7 million and $3.4 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	The Senior Credit Facility is secured by the membership interests of SE, SEG and the equity of the Co-Borrowers’ present and future subsidiaries, all of the Co-Borrowers’ and their subsidiaries’ present and future property and assets, including accounts receivable, inventory and liquid investments, and control agreements relating to bank accounts.
	The Senior Credit Facility contains covenants which, among other things, require the Company to maintain certain financial ratios or conditions. At all times, the Company must maintain net working capital, tangible net worth and a leverage ratio to a certain threshold. The Senior Credit Facility also contains negative covenants that limit our ability to, among other things, make certain payments, distributions, investments, acquisitions or loans.
	In addition, the Senior Credit Facility contains affirmative covenants that are customary for credit facilities of this type. The covenants include delivery of financial statements, including any filings made with the SEC, maintenance of property and insurance, payment of taxes and obligations, material compliance with laws, inspection of property, books and records and audits, use of proceeds, payments to bank blocked accounts, notice of defaults and certain other customary matters.

Fair_Value_Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements
	Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (exit price) in an orderly transaction between market participants at the measurement date. Fair values are based on assumptions that market participants would use when pricing an asset or liability, including assumptions about risk and the risks inherent in valuation techniques and the inputs to valuations. This includes not only the credit standing of counterparties involved and the impact of credit enhancements but also the impact of the Company’s own nonperformance risk on its liabilities.
	The Company applies fair value measurements to its commodity derivative instruments based on the following fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value into three broad levels:
	•	Level 1—Quoted prices in active markets for identical assets and liabilities. Instruments categorized in Level 1 primarily consist of financial instruments such as exchange-traded derivative instruments.
	•	Level 2—Inputs other than quoted prices recorded in Level 1 that are either directly or indirectly observable for the asset or liability, including quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in inactive markets, inputs other than quoted prices that are observable for the asset or liability, and inputs that are derived from observable market data by correlation or other means. Instruments categorized in Level 2 primarily include non-exchange traded derivatives such as over-the-counter commodity forwards and swaps and options.
	•	Level 3—Unobservable inputs for the asset or liability, including situations where there is little, if any, observable market activity for the asset or liability.
	As the fair value hierarchy gives the highest priority to quoted prices in active markets (Level 1) and the lowest priority to unobservable data (Level 3), the Company maximizes the use of observable inputs and minimizes the use of unobservable inputs when measuring fair value. In some cases, the inputs used to measure fair value might fall in different levels of the fair value hierarchy. In these cases, the lowest level input that is significant to a fair value measurement in its entirety determines the applicable level in the fair value hierarchy.
	Non-Derivative Financial Instruments
	The carrying amount of cash and cash equivalents, accounts receivable, accounts receivable-affiliates, accounts payable, accounts payable-affiliates, and accrued liabilities recorded in the combined and consolidated balance sheets approximate fair value due to the short-term nature of these items. The carrying amount of long-term debt recorded in the combined and consolidated balance sheets approximates fair value because of the variable rate nature of the Company’s long-term debt. The fair value of the payable pursuant to tax receivable agreement-affiliate is not determinable due to the affiliate nature and terms of the associated agreement with the affiliate.
	Derivative Instruments
	The following tables present assets and liabilities measured and recorded at fair value in the Company’s combined and consolidated balance sheets on a recurring basis by and their level within the fair value hierarchy as of (in thousands):
		Level 1			Level 2			Level 3		Total
	December 31, 2014
	Non-trading commodity derivative assets	$	—		$	80		$	—	$	80
	Trading commodity derivative assets	—			136			—		136
	Total commodity derivative assets	$	—		$	216		$	—	$	216
	Non-trading commodity derivative liabilities	$	(6,810	)	$	(5,017	)	$	—	$	(11,827	)
	Trading commodity derivative liabilities	(32		)	(145		)	—		(177		)
	Total commodity derivative liabilities	$	(6,842	)	$	(5,162	)	$	—	$	(12,004	)
		Level 1			Level 2			Level 3		Total
	December 31, 2013
	Non-trading commodity derivative assets	$	—		$	4,672		$	—	$	4,672
	Trading commodity derivative assets	—			3,405			—		3,405
	Total commodity derivative assets	$	—		$	8,077		$	—	$	8,077
	Non-trading commodity derivative liabilities	$	(563	)	$	(854	)	$	—	$	(1,417	)
	Trading commodity derivative liabilities	147			(581		)	—		(434		)
	Total commodity derivative liabilities	$	(416	)	$	(1,435	)	$	—	$	(1,851	)
	The Company had no financial instruments measured using level 3 at December 31, 2014 and 2013. The Company had no transfers of assets or liabilities between any of the above levels during the year ended December 31, 2014 and 2013.
	The Company’s derivative contracts include exchange-traded contracts fair valued utilizing readily available quoted market prices and non-exchange-traded contracts fair valued using market price quotations available through brokers or over-the-counter and on-line exchanges. In addition, in determining the fair value of the Company’s derivative contracts, the Company applies a credit risk valuation adjustment to reflect credit risk which is calculated based on the Company’s or the counterparty’s historical credit risks. As of December 31, 2014 and December 31, 2013, the credit risk valuation adjustment was not material.

Accounting_for_Derivative_Inst

Accounting for Derivative Instruments	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Accounting for Derivative Instruments	Accounting for Derivative Instruments
	The Company is exposed to the impact of market fluctuations in the price of electricity and natural gas and basis costs, storage and ancillary capacity charges from independent system operators. The Company uses derivative instruments to manage exposure to these risks, and historically designated certain derivative instruments as cash flow hedges for accounting purposes. For derivatives designated in a qualifying cash flow hedging relationship, the effective portion of the change in fair value is recognized in accumulated other comprehensive income (“OCI”) and reclassified to earnings in the period in which the hedged item affects earnings. Any ineffective portion of the derivative’s change in fair value is recognized currently in earnings.
	The Company also holds certain derivative instruments that are not held for trading purposes but are also not designated as hedges for accounting purposes. These derivative instruments represent economic hedges that mitigate the Company’s exposure to fluctuations in commodity prices. For these derivative instruments, changes in the fair value are recognized currently in earnings in retail revenues or retail costs of revenues, respectively.
	As part of the Company’s strategy to optimize its assets and manage related risks, it also manages a portfolio of commodity derivative instruments held for trading purposes. The Company’s commodity trading activities are subject to limits within the Company’s Risk Management Policy. For these derivative instruments, changes in the fair value are recognized currently in earnings in net asset optimization revenues.
	Derivative assets and liabilities are presented net in the Company’s combined and consolidated balance sheets when the derivative instruments are executed with the same counterparty under a master netting arrangement. The Company’s derivative contracts include transactions that are executed both on an exchange and centrally cleared as well as over-the-counter, bilateral contracts that are transacted directly with a third party. To the extent the Company has paid or received collateral related to the derivative assets or liabilities, such amounts would be presented net against the related derivative asset or liability’s fair value. As of December 31, 2014 and 2013, the Company had not paid or received any collateral amounts. The specific types of derivative instruments the Company may execute to manage the commodity price risk include the following:
	•Forward contracts, which commit the Company to purchase or sell energy commodities in the future;
	•Futures contracts, which are exchange-traded standardized commitments to purchase or sell a commodity or financial instrument;
	•Swap agreements, which require payments to or from counterparties based upon the differential between two prices for a predetermined notional quantity; and,
	•Option contracts, which convey to the option holder the right but not the obligation to purchase or sell a commodity.
	The Company has entered into other energy-related contracts that do not meet the definition of a derivative instrument or qualify for the normal purchase or normal sale exception and are therefore not accounted for at fair value including the following:
	•Forward electricity and natural gas purchase contracts for retail customer load; and,
	•Natural gas transportation contracts and storage agreements.
	Volumetric Underlying Derivative Transactions
	The following table summarizes the net notional volume buy/(sell) of the Company’s open derivative financial instruments accounted for at fair value, broken out by commodity, as of:
	Non-trading
	Commodity	Notional		31-Dec-14			31-Dec-13
	Natural Gas	MMBtu		9,690			3,513
	Natural Gas Basis	MMBtu		2,710			373
	Electricity	MWh		607			465
	Trading
	Commodity	Notional		31-Dec-14			31-Dec-13
	Natural Gas	MMBtu		(155	)		2,259
	Natural Gas Basis	MMBtu		(56	)		1,443
	Gains (Losses) on Derivative Instruments
	Gains (losses) on derivative instruments, net and current period settlements on derivative instruments were as follows for the periods indicated (in thousands):
		Year Ended December 31,
		2014				2013			2012
	Loss on non-trading derivatives—cash flow hedges, net (including ineffectiveness gain (loss) of ($288) and $930 for the years ended December 31, 2013 and 2012, respectively.)	$	—			$	84		$	(17,942	)
	Gain (loss) on non-trading derivatives, net	(8,713		)		1,345			(1,074		)
	Gain (loss) on trading derivatives, net (including gain on trading derivatives—affiliates, net of $203, $1,509 and $506 for the years ended December 31, 2014, 2013 and 2012, respectively)	(5,822		)		5,138			(2,469		)
	Gain (loss) on derivatives, net	$	(14,535	)		$	6,567		$	(21,485	)
	Current period settlements on non-trading derivatives—cash flow hedges	$	—			$	(1,180	)	$	18,707
	Current period settlements on non-trading derivatives	(6,289		)		1,833			7,782
	Current period settlements on trading derivatives (including current period settlements on trading derivatives—affiliates, net of $315, ($1,780) and $87 for the years ended December 31, 2014, 2013 and 2012, respectively)	2,810				387			312
	Total current period settlements on derivatives	$	(3,479	)		$	1,040		$	26,801
	Gains (losses) on trading derivative instruments are recorded in net asset optimization revenues and gains (losses) on non-trading derivative instruments are recorded in retail revenues or retail cost of revenues on the combined and consolidated statements of operations.
	Fair Value of Derivative Instruments
	The following tables summarize the fair value and offsetting amounts of the Company’s derivative instruments by counterparty and collateral received or paid as of (in thousands):
		December 31, 2014
	Description	Gross Assets				Gross			Net Assets			Cash		Net Amount
						Amounts						Collateral		Presented
						Offset						Offset
	Non-trading commodity derivatives	$	3,642			$	(3,562	)	$	80		$	—	$	80
	Trading commodity derivatives	234				(98		)	136			—		136
	Total Current Derivative Assets	3,876				(3,660		)	216			—		216
	Non-trading commodity derivatives	313				(313		)	—			—		—
	Total Non-current Derivative Assets	313				(313		)	—			—		—
	Total Derivative Assets	$	4,189			$	(3,973	)	$	216		$	—	$	216
		December 31, 2014
	Description	Gross				Gross			Net			Cash		Net Amount
		Liabilities				Amounts			Liabilities			Collateral		Presented
						Offset						Offset
	Non-trading commodity derivatives	$	(14,911	)		$	3,562		$	(11,349	)	$	—	$	(11,349	)
	Trading commodity derivatives	(275		)		98			(177		)	—		(177		)
	Total Current Derivative Liabilities	(15,186		)		3,660			(11,526		)	—		(11,526		)
	Non-trading commodity derivatives	(791		)		313			(478		)	—		(478		)
	Total Non-current Derivative Liabilities	(791		)		313			(478		)	—		(478		)
	Total Derivative Liabilities	$	(15,977	)		$	3,973		$	(12,004	)	$	—	$	(12,004	)
		December 31, 2013
	Description	Gross Assets				Gross			Net Assets			Cash		Net Amount
						Amounts						Collateral		Presented
						Offset						Offset
	Non-trading commodity derivatives	$	11,564			$	(6,898	)	$	4,666		$	—	$	4,666
	Trading commodity derivatives	3,949				(544		)	3,405			—		3,405
Total Current Derivative Assets	15,513				(7,442		)	8,071			—		8,071
Non-trading commodity derivatives	100				(94		)	6			—		6
Trading commodity derivatives	14				(14		)	—			—		—
Total Non-current Derivative Assets	114				(108		)	6			—		6
Total Derivative Assets	$	15,627			$	(7,550	)	$	8,077		$	—	$	8,077
	December 31, 2013
Description	Gross				Gross			Net			Cash		Net Amount
	Liabilities				Amounts			Liabilities			Collateral		Presented
					Offset						Offset
Non-trading commodity derivatives	$	(8,289	)		$	6,898		$	(1,391	)	$	—	$	(1,391	)
Trading commodity derivatives	(986		)		544			(442		)	—		(442		)
Total Current Derivative Liabilities	(9,275		)		7,442			(1,833		)	—		(1,833		)
Non-trading commodity derivatives	(120		)		94			(26		)	—		(26		)
Trading commodity derivatives	(6		)		14			8			—		8
Total Non-current Derivative Liabilities	(126		)		108			(18		)	—		(18		)
Total Derivative Liabilities	$	(9,401	)		$	7,550		$	(1,851	)	$	—	$	(1,851	)
Accumulated Other Comprehensive Income
The following table summarizes the effects on the Company’s accumulated OCI balance attributable to cash flow hedge derivative instruments for the periods indicated (in thousands):
	Year Ended December 31,
	2014				2013
Accumulated OCI balance, beginning of period	$	—			$	(2,536	)
Deferred gain (loss) on cash flow hedge derivative instruments	—				2,620
Reclassification of accumulated OCI net to income	—				(84		)
Accumulated OCI balance, end of period	$	—			$	—
The amounts reclassified from accumulated OCI into income and any amounts recognized in income from the ineffective portion of cash flow hedges are recorded in retail cost of revenues. In June 2013, the Company elected to discontinue cash flow hedge accounting.

Equity

Equity	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Equity	Equity
	Class A Common Stock
	The Company has a total of 3,000,000 shares of its Class A common stock outstanding at December 31, 2014. Each share of Class A common stock holds economic rights and entitles its holder to one vote on all matters to be voted on by shareholders generally.
	Class B Common Stock
	The Company has a total of 10,750,000 shares of its Class B common stock outstanding at December 31, 2014. Each share of Class B common stock, all of which is held by NuDevco, has no economic rights but entitles its holder to one vote on all matters to be voted on by shareholders generally.
	Holders of Class A common stock and Class B common stock vote together as a single class on all matters presented to our shareholders for their vote or approval, except as otherwise required by applicable law or by our certificate of incorporation.
	Preferred Stock
	The Company has 20,000,000 shares of authorized preferred stock for which there are no issued and outstanding shares at December 31, 2014.
	Earnings Per Share
	The Company’s unvested restricted stock units were not recognized in dilutive earnings per share as they would have been antidilutive. The Class B common stock conversion to Class A common stock was not recognized in dilutive earnings per share for the year ended December 31, 2014 as the effect of the conversion would be antidilutive.
	The following table presents the computation of earnings per share for the year ended December 31, 2014 (in thousands, except per share data):
		Year Ended
		31-Dec-14
	Net loss attributable to Spark Energy, Inc. stockholders	$	(54	)
	Basic weighted average Class A common shares outstanding (1)	3,000
	Basic EPS attributable to Spark Energy, Inc. stockholders	$	(0.02	)
	Net loss attributable to Spark Energy, Inc. stockholders	$	(54	)
	Effect of conversion of Class B common stock to shares of Class A common stock	—
	Diluted net loss attributable to Spark Energy, Inc. stockholders	(54		)
	Basic weighted average Class A common shares outstanding (1)	3,000
	Effect of dilutive Class B common stock (1)	—
	Effect of dilutive restricted stock units	—
	Diluted weighted average shares outstanding	3,000
	Diluted EPS attributable to Spark Energy, Inc. stockholders	$	(0.02	)
	(1) Based on outstanding shares for the period from the Offering date of August 1, 2014 to December 31, 2014.

StockBased_Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation
	Restricted Stock Units
	In connection with the Offering, the Company adopted the Spark Energy, Inc. Long-Term Incentive Plan (the “LTIP”) for the employees, consultants and directors of the Company and its affiliates who perform services for the Company. The purpose of the LTIP is to provide a means to attract and retain individuals to serve as directors, employees and consultants who provide services to the Company by affording such individuals a means to acquire and maintain ownership of awards, the value of which is tied to the performance of the Company’s Class A common stock. The LTIP provides for grants of cash payments, stock options, stock appreciation rights, restricted stock or units, bonus stock, dividend equivalents, and other stock-based awards with the total number of shares of stock available for issuance under the LTIP not to exceed 1,375,000 shares.
	On August 1, 2014, the Company granted restricted stock units to our employees, non-employee directors and certain employees of our affiliates who perform services for the Company. The restricted stock unit awards vest over a nine month period for non-employee directors and ratably over approximately three or four years for officers, employees, and employees of affiliates, depending on years of service at the grant date, with the initial vesting date occurring on May 4, 2015 and each subsequent vesting date occurring each May 4 thereafter. Each restricted stock unit is entitled to receive a dividend equivalent when dividends are declared and distributed to shareholders of Class A common stock. These dividend equivalents shall be retained by the Company, reinvested in additional restricted stock units effective as of the record date of such dividends and vested upon the same schedule as the underlying restricted stock unit. One dividend was declared and paid during the year ended December 31, 2014, and the dividends associated with unvested restricted stock units resulted in additional restricted stock units issued. In accordance with ASC 718, Compensation - Stock Compensation (“ASC 718”), the Company measures the cost of awards classified as equity awards based on the grant date fair value of the award, and the Company measures the cost of awards classified as liability awards at the fair value of the award at each reporting period. The Company has utilized an estimated 6% annual forfeiture rate of restricted stock units in determining the fair value for all awards excluding those issued to executive level recipients and non-employee directors, for which no forfeitures are estimated to occur. The Company has elected to recognize related compensation expense on a straight-line basis over the associated vesting periods. Although the restricted stock units allow for cash settlement of the awards at the sole discretion of management of the Company, management intends to settle the awards by issuing shares of the Company’s Class A common stock.
	Equity Classified Restricted Stock Units
	Restricted stock units issued to employees and officers of the Company are classified as equity awards. The fair value of the equity classified restricted stock units was based on the Company’s Class A common stock price as of the grant date, and the Company recognized stock based compensation expense of $0.5 million for the year ended December 31, 2014 in general and administrative expense with a corresponding increase to additional paid in capital. No compensation expense was recorded for the same periods in 2013 and 2012 as there were no LTIP awards outstanding.
	The following table summarizes equity classified restricted stock unit activity and unvested restricted stock units for the year ended December 31, 2014:
		Number of Shares		Weighted Average Grant Date Fair Value
	Unvested at December 31, 2013	—		—
	Granted	264,150		$	18
	Dividend reinvestment issuances	4,334		14.01
	Vested	—		—
	Forfeited	(11,600	)	18
	Unvested at December 31, 2014	256,884		$	17.93
	As of December 31, 2014, there was $4.1 million of total unrecognized compensation cost related to the Company’s equity classified restricted stock units, which is expected to be recognized over a weighted average period of approximately 3.2 years.
	Liability Classified Restricted Stock Units
	Restricted stock units issued to non-employee directors of the Company and employees of certain of our affiliates are classified as liability awards in accordance with ASC 718 as the awards are either to a) non-employee directors that allow for the recipient to choose net settlement for the amount of withholding taxes dues upon vesting or b) to employees of certain affiliates of the Company and are therefore not deemed to be employees of the Company. The fair value of the liability classified restricted stock units was based on the Company’s Class A common stock price as of the reported period ending date, and the Company recognized stock based compensation expense of $0.3 million for year ended December 31, 2014 in general and administrative expense with a corresponding increase to liabilities. As of December 31, 2014, the Company’s liabilities related to these restricted stock units recorded in other current liabilities and other non-current liabilities was $0.1 million and $0.2 million, respectively. No compensation expense was recorded for the same periods in 2013 and 2012 as there were no LTIP awards outstanding.
	The following table summarizes liability classified restricted stock unit activity and unvested restricted stock units for the year ended December 31, 2014:
		Number of Shares		Weighted Average Reporting Date Fair Value
	Unvested at December 31, 2013	—		—
	Granted	122,000		$	14.09
	Dividend reinvestment issuances	2,093		14.09
	Vested	—		—
	Forfeited	—		—
	Unvested at December 31, 2014	124,093		$	14.09
	As of December 31, 2014, there was $1.4 million of total unrecognized compensation cost related to the Company’s liability classified restricted stock units, which is expected to be recognized over a weighted average period of approximately 2.2 years.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	The Company is subject to U.S. federal income tax as a corporation. Spark HoldCo and its subsidiaries are treated as flow-through entities for U.S. federal income tax purposes, and as such, are generally not subject to U.S. federal income tax at the entity level. Rather, the tax liability with respect to their taxable income is passed through to their members or partners. Accordingly, the Company is subject to U.S. federal income taxation on its allocable share of Spark Holdco’s net U.S. taxable income.
	The (benefit) provision for income taxes included the following components:
	(in thousands)	2014			2013		2012
	Current:
	Federal	$	—		$	—	$	—
	State	173			56		46
	Total Current	173			56		46
	Deferred:
	Federal	(957		)	—		—
	State	(107		)	—		—
	Total Deferred	(1,064		)	—		—
	(Benefit) provision for income taxes	$	(891	)	$	56	$	46
	For the year ended December 31, 2013 and 2012, income taxes relate solely to the Company’s Texas franchise tax liability, which is computed on a modified gross margin. The Company does not do business in any other state where a similar tax is applied.
	The effective income tax rate was 17.3% for the year ended December 31, 2014. The following table reconciles the income tax benefit included in the combined and consolidated statement of operations with income tax expense that would result from application of the statutory federal tax rate, 34%, to loss before income tax expense:
	(in thousands)	2014
	Expected benefit at federal statutory rate	$	(1,753	)
	Increase (decrease) resulting from:
	Noncontrolling interest	1,451
	Corporate costs	(607		)
	State income taxes, net of federal income tax effect	69
	Other	(51		)
	Benefit for income taxes	$	(891	)
	For the year ended December 31, 2013 and 2012, the rate reconciliation calculation is not applicable as the Company was not subject to federal income taxes prior to the Offering.
	The Company accounts for income taxes using the assets and liabilities method. Deferred tax assets and liabilities are recognized for future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and those assets and liabilities tax bases. The Company applies existing tax law and the tax rate that the Company expects to apply to taxable income in the years in which those differences are expected to be recovered or settled in calculating the deferred tax assets and liabilities. Effects of changes in tax rates on deferred tax assets and liabilities are recognized in income in the period of the tax rate enactment. A valuation allowance is recorded when it is not more likely than not that some or all of the benefit from the deferred tax asset will be realized.
	The components of the Company’s deferred tax assets as of December 31, 2014 are as follows:
	(in thousands)	2014
	Current deferred tax assets:
	Net operating loss carryforward	$	654
	Non-current deferred tax assets:
	Investment in Spark HoldCo	16,171
	Benefit of TRA liability	7,817
	Net operating loss carryforward	59
	Total non-current deferred tax assets	24,047
	Total deferred tax assets	$	24,701
	Current deferred tax assets are recorded in other current assets in the combined and consolidated financial statements. The Company had no material deferred tax assets or liabilities as of December 31, 2013 and 2012.
	On the Offering date, the Company recorded a net deferred tax asset related to the step up in tax basis resulting from the purchase by the Company of Spark HoldCo units from NuDevco. In addition, the Company recorded a long-term liability to record the effect of the Tax Receivable Agreement liability (See Note 11 “Transactions with Affiliates” for further discussion) and a corresponding long-term deferred tax asset. The payable pursuant to the Tax Receivable Agreement and the deferred tax assets were recorded with a corresponding offset to additional paid-in capital.
	The Company has a federal net operating loss carry forward totaling $1.9 million expiring in 2034 and a state net operating loss of $1.8 million expiring through 2034. No valuation allowance has been recorded as management believes that there will be sufficient future taxable income to fully utilize deferred tax assets.
	The Company periodically assesses whether it is more likely than not that it will generate sufficient taxable income to realize its deferred income tax assets. In making this determination, the Company considers all available positive and negative evidence and makes certain assumptions. The Company considers, among other things, its deferred tax liabilities, the overall business environment, its historical earnings and losses, current industry trends, and its outlook for future years. The Company believes it is more likely than not that the deferred tax assets will be utilized.
	Separate federal and state income tax returns are filed for Spark Energy, Inc. and Spark HoldCo. The tax years 2010 through 2013 remain open to examination by the major taxing jurisdictions to which the Company is subject to income tax. NuDevco would be responsible for any audit adjustments incurred in connection with transactions occurring up to July 31, 2014. The last closed audit period of exam was for the 2011 Spark Energy, LLC’s federal tax return and resulted in no adjustments by the IRS.  The Company is not currently under any income tax audits.
	Accounting for uncertainty in income taxes prescribes a recognition threshold and measurement methodology for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. As of December 31, 2014, 2013 and 2012 there was no liability or expense recorded for interest and penalties associated with uncertain tax positions or unrecognized tax positions. Additionally, the Company does not have unrecognized tax benefits as of December 31, 2014, 2013 and 2012.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies
	From time to time, the Company may be involved in legal, tax, regulatory and other proceedings in the ordinary course of business. Management does not believe that we are a party to any litigation, claims or proceedings that will have a material impact on the Company’s combined and consolidated financial condition or results of operations.

Transactions_with_Affiliates

Transactions with Affiliates	12 Months Ended
	Dec. 31, 2014
Related Party Transactions [Abstract]
Transactions with Affiliates	Transactions with Affiliates
	The Company enters into transactions with and pays certain costs on behalf of affiliates that are commonly controlled in order to reduce risk, reduce administrative expense, create economies of scale, create strategic alliances and supply goods and services to these related parties. The Company also sells and purchases natural gas and electricity with affiliates. The Company presents receivables and payables with the same affiliate on a net basis in the combined and consolidated balance sheets as all affiliate activity is with parties under common control.
	Accounts Receivable and Payable-Affiliates
	The Company recorded current accounts receivable-affiliates of $1.2 million and $6.8 million as of December 31, 2014 and 2013, respectively, and current accounts payable-affiliates of $1.0 million as of December 31, 2014 for certain direct billings and cost allocations for services the Company provided to affiliates and sales or purchases of natural gas and electricity with affiliates.
	Revenues and Cost of Revenues-Affiliates
	Prior to Marlin’s initial public offering on July 31, 2013, the Company provided natural gas to Marlin, who is a processing service provider, whereby Marlin gathered natural gas from the Company and other third parties, extracted NGLs, and redelivered the processed natural gas to the Company and other third parties. Marlin replaced energy used in processing due to the extraction of liquids, compression and transportation of natural gas, and fuel by making a payment to the Company at market prices. Revenues-affiliates, recorded in net asset optimization revenues in the combined and consolidated statements of operations, related to Marlin’s payments to the Company for replaced energy for the years ended December 31, 2013 and 2012 were $3.0 million and $8.3 million, respectively.
	Beginning on August 1, 2013, the Marlin processing agreement was terminated and the Company and another affiliate entered into an agreement whereby the Company purchased natural gas from the affiliate at the tailgate of the Marlin plant. Cost of revenues-affiliates, recorded in net asset optimization revenues in the combined and consolidated statements of operations for the years ended December 31, 2014 and 2013 related to this agreement were $30.3 million and $17.7 million, respectively.
	The Company also purchased natural gas at a nearby third party plant inlet which was then sold to the affiliate. Revenues-affiliates, recorded in net asset optimization revenues in the combined and consolidated statements of operations for the years ended December 31, 2014 and 2013 related to these sales were $12.8 million and $11.9 million, respectively. There was no such activity in 2012.
	Additionally, the Company entered into a natural gas transportation agreement with Marlin, at Marlin’s pipeline, whereby the Company transports retail natural gas and pays the higher of (i) a minimum monthly payment or (ii) a transportation fee per MMBtu times actual volumes transported. The current transportation agreement was set to expire on February 28, 2013, but was extended for three additional years at a fixed rate per MMBtu without a minimum monthly payment. Included in the Company’s results are cost of revenues-affiliates, recorded in retail cost of revenues in the combined and consolidated statements of operations related to this activity, which was less than $0.1 million, $0.1 million and $0.3 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Prior to the Offering, the Company also purchased electricity for an affiliate and sold the electricity to the affiliate at the same market price that the Company paid to purchase the electricity. Sales of electricity to the affiliate were $2.2 million, $4.0 million and $1.4 million for the years ended December 31, 2014, 2013 and 2012, respectively, which is recorded in retail revenues-affiliate in the combined and consolidated statements of operations.
	Also included in the Company’s results are cost of revenues-affiliates related to derivative instruments, recorded in net asset optimization revenues in the combined and consolidated statements of operations, is a loss of $0.6 million, a gain of $1.8 million and a loss of $0.6 million for the years ended December 31, 2014, 2013 and 2012, respectively.
	Cost Allocations
	The Company paid certain expenses on behalf of affiliates, which are reimbursed by the affiliates to the Company, including costs that can be specifically identified and certain allocated overhead costs associated with general and administrative services, including executive management, facilities, banking arrangements, professional fees, insurance, information services, human resources and other support departments to the affiliates. Where costs incurred on behalf of the affiliate could not be determined by specific identification for direct billing, the costs were primarily allocated to the affiliated entities based on percentage of departmental usage, wages or headcount. The total amount direct billed and allocated to affiliates was $5.1 million, $7.4 million and $4.1 million for the years ended December 31, 2014, 2013 and 2012, respectively, which is recorded as a reduction in general and administrative expenses in the combined and consolidated statements of operations.
	The Company pays residual commissions to an affiliate for all customers enrolled by the affiliate who pay their monthly retail gas or retail electricity bill. Commissions paid to the affiliate was less than $0.1 million for the years ended December 31, 2014 and 2013, respectively, and $0.8 million for the year ended December 31, 2012, which is recorded in general and administrative expense in the combined and consolidated statements of operations. This agreement with the affiliate was terminated in May 2014.
	Member Distributions and Contributions
	During the years ended December 31, 2014, 2013 and 2012, the Company made net capital distributions to W. Keith Maxwell III of $36.4 million, $59.3 million and $10.4 million, respectively. In contemplation of the Company’s initial public offering, the Company entered into an agreement with an affiliate in April 2014 to permanently forgive all net outstanding accounts receivable balances from the affiliate through the Offering date. As such, the accounts receivable balances from the affiliate have been eliminated and presented as a distribution to W. Keith Maxwell III for 2014, 2013 and 2012.
	Property and Equipment Sold
	In 2012, the Company sold a field office facility, vehicles and computer and other equipment to affiliates for $0.6 million. The assets were sold at the Company’s historical cost basis at the time of the sale, as the transactions were between affiliates under common control.
	Tax Receivable Agreement
	Concurrently with the closing of the Offering, the Company entered into a Tax Receivable Agreement with Spark HoldCo, NuDevco Retail Holdings and NuDevco Retail. This agreement generally provides for the payment by the Company to NuDevco of 85% of the net cash savings, if any, in U.S. federal, state and local income tax or franchise tax that the Company actually realizes (or is deemed to realize in certain circumstances) in future periods as a result of (i) any tax basis increases resulting from the purchase by the Company of Spark HoldCo units from NuDevco Retail Holdings in connection with the Offering, (ii) any tax basis increases resulting from the exchange of Spark HoldCo units for shares of Class A common stock pursuant to the Exchange Right (or resulting from an exchange of Spark HoldCo units for cash pursuant to the Cash Option) and (iii) any imputed interest deemed to be paid by the Company as a result of, and additional tax basis arising from, any payments the Company makes under the Tax Receivable Agreement. In addition, payments we make under the Tax Receivable Agreement will be increased by any interest accrued from the due date (without extensions) of the corresponding tax return. The Company retains the benefit of the remaining 15% of these tax savings. See Note 9 “Taxes” for further discussion of amounts recorded in connection with the Offering.
	In certain circumstances, the Company may defer or partially defer any payment due (a “TRA Payment”) to the holders of rights under the Tax Receivable Agreement, which are currently NuDevco Retail Holdings and NuDevco Retail. No TRA Payment was made during 2014, and any future TRA Payments due with respect to a given taxable year are expected to be paid in December of the subsequent calendar year.
	During the five-year period commencing October 1, 2014, the Company will defer all or a portion of any TRA Payment owed pursuant to the Tax Receivable Agreement to the extent that Spark HoldCo does not generate sufficient Cash Available for Distribution (as defined below) during the four-quarter period ending September 30th of the applicable year in which the TRA Payment is to be made in an amount that equals or exceeds 130% (the “TRA Coverage Ratio”) of the Total Distributions (as defined below) paid in such four-quarter period by Spark HoldCo. For purposes of computing the TRA Coverage Ratio:
	•	“Cash Available for Distribution” is generally defined as the Adjusted EBITDA of Spark HoldCo for the applicable period, less (i) cash interest paid by Spark HoldCo, (ii) capital expenditures of Spark HoldCo (exclusive of customer acquisition costs) and (iii) any taxes payable by Spark HoldCo; and
	•	“Total Distributions” are defined as the aggregate distributions necessary to cause the Company to receive distributions of cash equal to (i) the targeted quarterly distribution the Company intends to pay to holders of its Class A common stock payable during the applicable four-quarter period, plus (ii) the estimated taxes payable by the Company during such four-quarter period, plus (iii) the expected TRA Payment payable during the calendar year for which the TRA Coverage Ratio is being tested.
	In the event that the TRA Coverage Ratio is not satisfied in any calendar year, the Company will defer all or a portion of the TRA Payment to NuDevco under the Tax Receivable Agreement to the extent necessary to permit Spark HoldCo to satisfy the TRA Coverage Ratio (and Spark HoldCo is not required to make and will not make the pro rata distributions to its members with respect to the deferred portion of the TRA Payment). If the TRA Coverage Ratio is satisfied in any calendar year, the Company will pay NuDevco the full amount of the TRA Payment.
	Following the five-year deferral period, the Company will be obligated to pay any outstanding deferred TRA Payments to the extent such deferred TRA Payments do not exceed (i) the lesser of the Company’s proportionate share of aggregate Cash Available for Distribution of Spark HoldCo during the five-year deferral period or the cash distributions actually received by the Company during the five-year deferral period, reduced by (ii) the sum of (a) the aggregate target quarterly dividends (which, for the purposes of the Tax Receivable Agreement, will be $0.3625 per share per quarter) during the five-year deferral period, (b) the Company’s estimated taxes during the five-year deferral period, and (c) all prior TRA Payments and (y) if with respect to the quarterly period during which the deferred TRA Payment is otherwise paid or payable, Spark HoldCo has or reasonably determines it will have amounts necessary to cause the Company to receive distributions of cash equal to the target quarterly distribution payable during that quarterly period. Any portion of the deferred TRA Payments not payable due to these limitations will no longer be payable.

Segment_Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Segment Reporting	Segment Reporting
	The Company’s determination of reportable business segments considers the strategic operating units under which the Company makes financial decisions, allocates resources and assesses performance of its retail and asset optimization businesses.
	The Company’s reportable business segments are retail natural gas and retail electricity. The retail natural gas segment consists of natural gas sales to, and natural gas transportation and distribution for, residential and commercial customers. Asset optimization activities, considered an integral part of securing the lowest price natural gas to serve retail gas load, are part of the retail natural gas segment. The Company recorded asset optimization revenues of $284.6 million, $192.4 million and $248.6 million and asset optimization cost of revenues of $282.3 million, $192.1 million and $249.7 million for the years ended December 31, 2014, 2013 and 2012, respectively, which are presented on a net basis in asset optimization revenues. The retail electricity segment consists of electricity sales and transmission to residential and commercial customers. Corporate and other consists of expenses and assets of the retail natural gas and retail electricity segments that are managed at a consolidated level such as general and administrative expenses.
	To assess the performance of the Company’s operating segments, the chief operating decision maker analyzes retail gross margin. The Company defines retail gross margin as operating income plus (i) depreciation and amortization expenses and (ii) general and administrative expenses, less (i) net asset optimization revenues, (ii) net gains (losses) on non-trading derivative instruments, and (iii) net current period cash settlements on non-trading derivative instruments. The Company deducts net gains (losses) on non-trading derivative instruments, excluding current period cash settlements, from the retail gross margin calculation in order to remove the non-cash impact of net gains and losses on non-trading derivative instruments.
	Retail gross margin is a primary performance measure used by our management to determine the performance of our retail natural gas and electricity business by removing the impacts of our asset optimization activities and net non-cash income (loss) impact of our economic hedging activities. As an indicator of our retail energy business’ operating performance, retail gross margin should not be considered an alternative to, or more meaningful than, operating income, as determined in accordance with GAAP. Below is a reconciliation of retail gross margin to (loss) income before income tax expense.
			Years Ended December 31,
	(in thousands)		2014				2013				2012
	Reconciliation of Retail Gross Margin to (Loss)income before taxes
	(Loss) income before income tax expense		$	(5,156	)		$	31,468			$	26,139
	Interest and other income		(263		)		(353		)		(62		)
	Interest expense		1,578				1,714				3,363
	Operating Income		(3,841		)		32,829				29,440
	Depreciation and amortization		22,221				16,215				22,795
	General and administrative		45,880				35,020				47,321
	Less:
	Net asset optimization revenue		2,318				314				(1,136		)
	Net, Gains (losses) on non-trading derivative instruments		(8,713		)		1,429				(19,016		)
	Net, Cash settlements on non-trading derivative instruments		(6,289		)		653				26,489
	Retail Gross Margin		$	76,944			$	81,668			$	93,219
	The Company uses retail gross margin and net asset optimization revenues as the measure of profit or loss for its business segments. This measure represents the lowest level of information that is provided to the chief operating decision maker for our reportable segments.
	Financial data for business segments are as follows (in thousands):
	Year Ended December 31, 2014	Retail				Retail				Corporate				Eliminations			Total Spark Retail
		Electricity				Natural Gas				and Other
	Total Revenues	$	176,406			$	146,470			$	—			$	—		$	322,876
	Retail cost of revenues	149,452				109,164				—				—			258,616
	Less:
	Net asset optimization revenues	—				2,318				—				—			2,318
	Net, Gains (losses) on non-trading derivative instruments	(518		)		(8,195		)		—				—			(8,713		)
	Current period settlements on non-trading derivatives	(5,145		)		(1,144		)		—				—			(6,289		)
	Retail gross margin	$	32,617			$	44,327			$	—			$	—		$	76,944
	Total Assets	$	46,848			$	101,711			$	27,285			$	(37,447	)	$	138,397
	Year Ended December 31, 2013	Retail				Retail				Corporate				Eliminations			Total Spark Retail
		Electricity				Natural Gas				and Other
	Total Revenues	$	191,872			$	125,218			$	—			$	—		$	317,090
	Retail cost of revenues	149,885				83,141				—				—			233,026
	Less:
	Net asset optimization revenues	—				314				—				—			314
	Net, Gains (losses) on non-trading derivative instruments	1,336				93				—				—			1,429
	Current period settlements on non-trading derivatives	1,349				(696		)		—				—			653
	Retail gross margin	$	39,302			$	42,366			$	—			$	—		$	81,668
	Total Assets	$	41,879			$	87,985			$	953			$	(21,744	)	$	109,073
	Year Ended December 31, 2012	Retail				Retail				Corporate				Eliminations			Spark Retail
		Electricity				Natural Gas				and Other
	Total Revenues	$	256,357			$	122,705			$	—			$	—		$	379,062
	Retail cost of revenues	202,440				77,066				—				—			279,506
	Less:
	Net asset optimization revenues	—				(1,136		)		—				—			(1,136		)
	Net, Gains (losses) on non-trading derivative instruments	(17,400		)		(1,616		)		—				—			$	(19,016	)
	Current period settlements on non-trading derivatives	18,577				7,912				—				—			26,489
	Retail gross margin	$	52,740			$	40,479			$	—			$	—		$	93,219
	Significant Customers
	For the years ended December 31, 2014, 2013 and 2012, we had one significant customer that individually accounted for more than 10% of the Company’s combined and consolidated net asset optimization revenues.
	Significant Suppliers
	For the years ended December 31, 2014, 2013 and 2012, we had one significant supplier that individually accounted for more than 10% of the Company’s combined and consolidated net asset optimization revenues cost of revenues.
	For the years ended December 31, 2014, and 2013, the Company had three and one significant suppliers that individually accounted for more than 10% of the Company’s combined and consolidated retail electricity retail cost of revenues, respectively. There were no significant suppliers for retail electricity in 2012.

Customer_Acquisitions

Customer Acquisitions	12 Months Ended
	Dec. 31, 2014
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Customer Acquisitions	Customer Acquisitions
	During the fourth quarter of 2014, the Company entered into two purchase and sale agreements for the purchase of approximately 13,400 variable rate electricity contracts in Connecticut for a purchase price of approximately $2.2 million. The purchase prices are capitalized as intangible assets - customer acquisitions to be amortized over a three year period as customers begin using electricity under a contract with the Company. As of December 31, 2014 the Company had paid and capitalized approximately $1.5 million related to these purchases.

Subsequent_Events

Subsequent Events	12 Months Ended
	Dec. 31, 2014
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events
	On February 16, 2015, the Company declared a dividend of $0.3625 per share to holders of record of our Class A common stock on March 2, 2015 which was paid on March 16, 2015.
	On March 3, 2015, the Company entered into a purchase and sale agreement for the purchase of approximately 33,500 residential and commercial natural gas contracts in Northern California for a purchase price of approximately $2.8 million, depending on the number of contracts that come on flow. The transaction is expected to close in April 2015 subject to certain closing conditions.

Basis_of_Presentation_and_Summ1

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies
	The accompanying combined and consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). All significant intercompany transactions and balances have been eliminated in the combined and consolidated financial statements.
	The accompanying combined and consolidated financial statements have been prepared in accordance with Regulation S-X, Article 3, General Instructions as to Financial Statements and Staff Accounting Bulletin (“SAB”) Topic 1-B, Allocations of Expenses and Related Disclosures in Financial Statements of Subsidiaries, Divisions or Lesser Business Components of Another Entity on a stand-alone basis and are derived from SE’s and SEG’s historical basis in the assets and liabilities before the Offering and Spark Energy Inc.’s financial results after the Offering, and include all revenues, costs, assets and liabilities attributable to the retail natural gas and asset optimization and retail electricity businesses of SE and SEG for the periods prior to the Offering that are specifically identifiable or have been allocated to the Company. Management has made certain assumptions and estimates in order to allocate a reasonable share of expenses to the Company, such that the Company’s combined and consolidated financial statements reflect substantially all of its costs of doing business. The Company also enters into transactions with and pays certain costs on behalf of affiliates under common control in order to reduce risk, reduce administrative expense, create economies of scale, create strategic alliances and supply goods and services to these related parties. The Company direct bills certain expenses incurred on behalf of affiliates or allocates certain overhead expenses to affiliates associated with general and administrative services based on services provided, departmental usage, or headcount, which are considered reasonable by management. The allocations and related estimates and assumptions are described more fully in Note 11 “Transactions with Affiliates”. These costs are not necessarily indicative of the cost that the Company would have incurred had it operated as an independent stand-alone entity prior to the Offering. Affiliates have also relied upon Spark Energy Ventures as a participant in the credit facility for periods prior to the Offering as described more fully in Note 4 “Long-Term Debt”. As such, the Company’s combined and consolidated financial statements do not fully reflect what the Company’s financial position, results of operations and cash flows would have been had the Company operated as an independent stand-alone company prior to the Offering. As a result, historical financial information prior to the Offering is not necessarily indicative of what the Company’s results of operations, financial position and cash flows will be in the future. The Company’s combined and consolidated financial statements include all wholly-owned and controlled subsidiaries.
Cash and Cash Equivalents	Cash and Cash Equivalents
	Cash and cash equivalents consist of all unrestricted demand deposits and funds invested in highly liquid instruments with original maturities of three months or less. The Company periodically assesses the financial condition of the institutions where these funds are held and believes that its credit risk is minimal with respect to these institutions.
Restricted Cash	Restricted Cash
	Restricted cash consists of cash that has been placed in escrow for a contractually designated future use.
Accounts Receivables	Accounts Receivable
	Trade accounts receivable are recorded at the invoiced amount and do not bear interest. Accounts receivable in the combined and consolidated balance sheets are net of allowance for doubtful accounts of $8.0 million and $1.2 million as of December 31, 2014 and 2013, respectively.
	The Company accrues an allowance for doubtful accounts based upon estimated uncollectible accounts receivable considering historical collections, accounts receivable aging analysis, credit risk and other factors. The Company writes off accounts receivable balances against the allowance for doubtful accounts when the accounts receivable is deemed to be uncollectible. Bad debt expense of $10.2 million, $3.1 million and $1.8 million was recorded in general and administrative expense in the combined and consolidated statements of operations for the years ended December 31, 2014, 2013 and 2012, respectively.
	The Company conducts business in many utility service markets where the local regulated utility is responsible for billing the customer, collecting payment from the customer and remitting payment to the Company (“POR programs”). This POR service results in substantially all of the Company’s credit risk being linked to the applicable utility, which generally has an investment-grade rating, and not to the end-use customer. The Company monitors the financial condition of each utility and currently believes that its susceptibility to an individually significant write-off as a result of concentrations of customer accounts receivable with those utilities is remote. Trade accounts receivable that are part of a local regulated utility’s POR program are recorded on a gross basis in accounts receivable in the combined and consolidated balance sheets. The discount paid to the local regulated utilities is recorded in general and administrative expense in the combined and consolidated statements of operations.
	In markets that do not offer POR services or when the Company chooses to directly bill its customers, certain receivables are billed and collected by the Company. The Company bears the credit risk on these accounts and records an appropriate allowance for doubtful accounts to reflect any losses due to non-payment by customers. The Company’s customers are individually insignificant and geographically dispersed in these markets. The Company writes off customer balances when it believes that amounts are no longer collectible and when it has exhausted all means to collect these receivables.
Inventory	Inventory
	Inventory consists of natural gas used to fulfill and manage seasonality for fixed and variable-price retail customer load requirements and is valued at the lower of weighted average cost or market. Purchased natural gas costs are recognized in the combined and consolidated statements of operations, within retail cost of revenues, when the natural gas is sold and delivered out of the storage facility. There were no inventory impairments recorded for the years ended December 31, 2014, 2013 and 2012. When natural gas is sold costs are recognized in the combined and consolidated statements of operations, within retail cost of revenues, at the weighted average cost value at the time of the sale.
Customer Acquisition Costs	Customer Acquisition Costs
	The Company has retail natural gas and electricity customer acquisition costs, net of $12.4 million and $4.8 million recorded in current assets and $3.0 million and $2.9 million recorded in noncurrent assets representing direct response advertising costs as of December 31, 2014 and 2013, respectively. Customer acquisition costs is spending for organic customer acquisitions and does not include customer acquisitions through merger and acquisition activities, which are recorded as intangible assets. Amortization of customer acquisition costs, recorded in depreciation and amortization in the combined and consolidated statements of operations, was $18.5 million, $10.1 million and $16.4 million for the years ended December 31, 2014, 2013 and 2012, respectively. Capitalized direct response advertising costs consist primarily of hourly and commission based telemarketing costs, door-to-door agent commissions and other direct advertising costs associated with proven customer generation, and are capitalized and amortized over the estimated two-year average life of a customer in accordance with the provisions of FASB ASC 340-20, Capitalized Advertising Costs.
	Recoverability of customer acquisition costs is evaluated based on a comparison of the carrying amount of the customer acquisition costs to the future net cash flows expected to be generated by the customers acquired, considering specific assumptions for customer attrition, per unit gross profit, and operating costs. These assumptions are based on forecasts and historical experience.
Intangibles - Customer Acquisition	Intangibles - Customer Acquisitions
	Customer acquisitions through merger and acquisition activities are recorded as intangible assets and represent customer contract acquisitions not acquired through the direct response advertising discussed above at “Customer Acquisition Costs”. The Company has recorded $1.5 million, net of amortization, as of December 31, 2014 related to these intangible assets. These intangibles are amortized over the estimated three-year average life of the related customer contracts acquired.
	We review intangible assets for impairment whenever events or changes in business circumstances indicate the carrying value of the intangible assets may not be recoverable. Impairment is indicated when the undiscounted cash flows estimated to be generated by the intangible assets are less than their respective carrying value. If an impairment exists, a loss would be recognized for the difference between the fair value and carrying value of the intangible assets. No impairments of intangible assets were recorded in 2014, 2013 and 2012.
Deferred Financing Costs	Deferred Financing Costs
	Costs incurred in connection with the issuance of long-term debt are capitalized and amortized to interest expense using the straight-line method over the life of the related long-term debt due to the variable nature of the Company’s long-term debt.
Property and Equipment	Property and Equipment
	The Company records property and equipment at historical cost. Depreciation expense is recorded on a straight-line method based on estimated useful lives. When assets are placed into service, management makes estimates with respect to useful lives and salvage values of the assets.
	When items of property and equipment are sold or otherwise disposed of, any gain or loss is recorded in the combined and consolidated statements of operations.
Internal-Use Software	The Company capitalizes costs associated with internal-use software projects in accordance with FASB ASC Topic 350-40, Internal-Use Software. Capitalized costs are the costs incurred during the application development stage of the internal-use software project such as software configuration, coding, installation of hardware and testing. Costs incurred during the preliminary or post-implementation stage of the internal-use software project are expensed in the period incurred. These types of costs include formulation of ideas and alternatives, training and application maintenance. After internal-use software projects are completed, the associated capitalized costs are depreciated over the estimated useful life of the related asset. Interest costs incurred while developing internal-use software projects are capitalized in accordance with FASB ASC Topic 835-20, Capitalization of Interest. Capitalized interest costs for the years ended December 31, 2014, 2013 and 2012 were not material.
Segment Reporting	Segment Reporting
	The FASB ASC Topic 280, Segment Reporting, established standards for entities to report information about the operating segments and geographic areas in which they operate. The Company operates two segments, retail natural gas and retail electricity, and all of its operations are located in the United States.
Revenues and Cost of Revenues	Revenues and Cost of Revenues
	The Company’s revenues are derived primarily from the sale of natural gas and electricity to retail customers. The company also records revenue from sales of natural gas and electricity to wholesale counterparties, including affiliates. Revenues are recognized by the Company using the following criteria: (1) persuasive evidence of an exchange arrangement exists, (2) delivery has occurred or services have been rendered, (3) the buyer’s price is fixed or determinable and (4) collection is reasonably assured. Utilizing these criteria, revenue is recognized when the natural gas or electricity is delivered. Similarly, cost of revenues is recognized when the commodity is delivered.
	Revenues for natural gas and electricity sales are recognized upon delivery under the accrual method. Natural gas and electricity sales that have been delivered but not billed by period end are estimated. Accrued unbilled revenues are based on estimates of customer usage since the date of the last meter read provided by the utility. Volume estimates are based on forecasted volumes and estimated customer usage by class. Unbilled revenues are calculated by multiplying these volume estimates by the applicable rate by customer class. Estimated amounts are adjusted when actual usage is known and billed.
	The Company records gross receipts taxes on a gross basis in retail revenues and retail cost of revenues. During the years ended December 31, 2014, 2013 and 2012, the Company’s retail revenues and retail cost of revenues included gross receipts taxes of $3.0 million, $3.5 million and $5.1 million, respectively.
	Costs for natural gas and electricity sales are recognized as the commodity is delivered to the customer under the accrual method. Natural gas and electricity costs that have not been billed to the Company by suppliers but have been incurred by period end are estimated. The Company estimates volumes for natural gas and electricity delivered based on the forecasted revenue volumes, estimated transportation cost volumes and estimation of other costs associated with retail load which varies by commodity utility territory. These costs include items like ISO fees, ancillary services and renewable energy credits. Estimated amounts are adjusted when actual usage is known and billed.
	The Company’s asset optimization activities, which primarily include natural gas physical arbitrage and other short term storage and transportation opportunities, meet the definition of trading activities and are recorded on a net basis in the combined and consolidated statements of operations in net asset optimization revenues pursuant to FASB ASC 815, Derivatives and Hedging.
Natural Gas Imbalances	Natural Gas Imbalances
	The combined and consolidated balance sheets include natural gas imbalance receivables and payables, which primarily results when customers consume more or less gas than has been delivered by the Company to local distribution companies (“LDCs”). The settlement of natural gas imbalances varies by LDC, but typically the natural gas imbalances are settled in cash or in kind on a monthly, quarterly, semi-annual or annual basis. The imbalances are valued at an estimated net realizable value.
Fair Value	Fair Value
	FASB ASC 820, Fair Value Measurement, established a single authoritative definition of fair value, set out a framework for measuring fair value, and requires disclosures about fair value measurements. The standard clarifies that fair value is an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. The standard utilizes a fair value hierarchy that prioritizes the inputs to the valuation techniques used to measure fair value into three broad levels based on quoted prices in active market, observable market prices, and unobservable market prices.
	When the Company is required to measure fair value, and there is not a quoted or observable market price for a similar asset or liability, the Company utilizes the cost, income, or market valuation approach depending on the quality of information available to support management’s assumptions.
Derivative Instruments	Derivative Instruments
	The Company uses derivative instruments such as futures, swaps, forwards and options to manage the commodity price risks of its business operations.
	All derivatives, other than those for which an exception applies, are recorded in the combined and consolidated balance sheets at fair value. Derivative instruments representing unrealized gains are reported as derivative assets while derivative instruments representing unrealized losses are reported as derivative liabilities. The Company has elected to offset amounts in the combined and consolidated balance sheets for derivative instruments executed with the same counterparty under a master netting arrangement. One of the exceptions to fair value accounting, normal purchases and normal sales, has been elected by the Company for certain derivative instruments when the contract satisfies certain criteria, including a requirement that physical delivery of the underlying commodity is probable and is expected to be used in normal course of business. Retail revenues and retail cost of revenues resulting from deliveries of commodities under normal purchase contracts and normal sales contracts are included in earnings at the time of contract settlement.
	To manage commodity price risk, the Company holds certain derivative instruments that are not held for trading purposes and are not designated as hedges for accounting purposes. However, to the extent the Company does not hold offsetting positions for such derivatives, they believe these instruments represent economic hedges that mitigate their exposure to fluctuations in commodity prices. As part of the Company’s strategy to optimize its assets and manage related commodity risks, it also manages a portfolio of commodity derivative instruments held for trading purposes. The Company uses established policies and procedures to manage the risks associated with price fluctuations in these energy commodities and uses derivative instruments to reduce risk by generally creating offsetting market positions.
	Changes in the fair value of and amounts realized upon settlement of derivative instruments not held for trading purposes are recognized currently in earnings in retail revenues or retail costs of revenues, respectively.
	Changes in the fair value of and amounts realized upon settlement of derivative instruments held for trading purposes are recognized currently in earnings in net asset optimization revenues.
	The Company has historically designated a portion of our derivative instruments as cash flow hedges for accounting purposes. For all hedging transactions, the Company formally documented the hedging transaction and its risk management objective and strategy for undertaking the hedge, the hedging instrument, the nature of the risk being hedged, how the hedging instrument’s effectiveness in offsetting the hedged risk was assessed prospectively and retrospectively, and a description of the method used to measure ineffectiveness. The Company also formally assessed, both at the inception of the hedging transaction and on an ongoing basis, whether the derivatives used in hedging transactions were highly effective in offsetting changes in cash flows of hedged transactions. For derivative instruments that were designated and qualified as part of a cash flow hedging transaction, the effective portion of the gain or loss on the derivative was reported as a component of other comprehensive income and reclassified into earnings in the same period or periods during when the hedged transaction affected earnings. Gains and losses on the derivative representing either hedge ineffectiveness or hedge components excluded from the assessment of effectiveness were recognized in current earnings. Hedge accounting was discontinued prospectively for derivatives that ceased to be highly effective hedges or when the occurrence of the forecasted transaction was no longer probable.
	Effective July 1, 2013, the Company elected to discontinue hedge accounting prospectively and began to record the changes in fair value recognized in the combined and consolidated statement of operations in the period of change. Because the underlying transactions were still probable of occurring, the related accumulated OCI was frozen and recognized in earnings as the underlying hedged item was delivered. As of December 31, 2014 and 2013, the Company has no gains or losses on derivatives that were designated as qualifying cash flow hedging transactions recorded as a component of accumulated OCI, as all previously deferred gains and losses on qualifying hedge transactions were reclassified into earnings during the year ended December 31, 2013 and 2012 when the associated hedged transactions were recorded into earnings.
Income Taxes	Income Taxes
	The Company recognizes the amount of taxes payable or refundable for the year. In addition, the Company follows the asset and liability method of accounting for income taxes where deferred tax assets and liabilities are recognized for the expected future tax consequences of events that have been recognized in the financial statements or tax returns and operating loss carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in those years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in the tax rates is recognized in income in the period that includes the enactment date. A valuation allowance is provided for deferred tax assets if it is more likely than not that these items will not be realized.
	In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will not be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Management considers the projected future taxable income and tax planning strategies in making this assessment. Based upon the level of historical taxable income and projections for future taxable income over the periods in which the deferred tax assets are deductible, management believes it is more likely than not that we will realize the benefits of these deductible differences.
	The Company recognizes interest and penalties related to unrecognized tax benefits within the provision for income taxes on continuing operations in our consolidated statements of operations.
Earnings Per Share	Earnings per Share
	Basic earnings per share (“EPS”) is computed by dividing net income attributable to shareholders (the numerator) by the weighted-average number of Class A common shares outstanding for the period (the denominator). Class B common shares are not included in the calculation of basic earnings per share because they have no economic interest in the Company. Diluted earnings per share is similarly calculated except that the denominator is increased (1) using the treasury stock method to determine the potential dilutive effect of the Company’s outstanding unvested restricted stock units and (2) using the if-converted method to determine the potential dilutive effect of the Company’s Class B common stock. The Company has omitted earnings per share prior to the Offering because the Company operated under a sole member equity structure for those periods.
Commitments and Contingencies	Commitments and Contingencies
	The Company enters into various firm purchase and sale commitments for natural gas, storage, transportation, and electricity that do not meet the definition of a derivative instrument or for which the Company has elected the normal purchase or normal sales exception. Management does not anticipate that such commitments will result in any significant gains or losses based on current market conditions.
	Liabilities for loss contingencies arising from claims, assessments, litigation, fines, penalties and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. Legal costs incurred in connection with loss contingencies are expensed as incurred.
Transactions with Affiliates	Transactions with Affiliates
	The Company enters into transactions with and incurs certain costs on behalf of affiliates that are commonly controlled by NuDevco Partners Holdings in order to reduce risk, reduce administrative expense, create economies of scale, create strategic alliances and supply goods and services to these related parties. These transactions include, but are not limited to, certain services to the affiliated companies associated with the Company’s debt facility prior to the Offering, employee benefits provided through the Company’s benefit plans, insurance plans, leased office space, and administrative salaries for accounting, tax, legal, or technology services. As such, the accompanying combined and consolidated financial statements include costs that have been incurred by the Company and then directly billed or allocated to affiliates and are recorded net in general and administrative expense on the combined and consolidated statements of operations with a corresponding accounts receivable-affiliates recorded in the combined and consolidated balance sheets. Additionally, the Company enters into transactions with certain affiliates for sales or purchases of natural gas and electricity, which are recorded in retail revenues, retail cost of revenues, and net asset optimization revenues in the combined and consolidated statements of operations with a corresponding accounts receivable-affiliate or accounts payable-affiliate in the combined and consolidated balance sheets. See Note 11, “Transactions with Affiliates” for further discussion.
Use of Estimates and Assumptions	Use of Estimates and Assumptions
	The preparation of the Company’s combined and consolidated financial statements requires estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the combined financial statements and the reported amounts of revenues and expenses during the period. Actual results could materially differ from those estimates. Significant items subject to such estimates by the Company’s management include estimates for unbilled revenues and related cost of revenues, provisions for uncollectible receivables, valuation of customer acquisition costs, estimated useful lives of property and equipment, valuation of derivatives and reserves for contingencies.
Subsequent Events	Subsequent Events
	Subsequent events have been evaluated through the date these financial statements are issued. Any material subsequent events that occurred prior to such date have been properly recognized or disclosed in the combined and consolidated financial statements. See Note 14 “Subsequent Events” for further discussion.
Recent Accounting Pronouncements	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. ASU 2014-09 will replace most existing revenue recognition guidance in GAAP when it becomes effective on January 1, 2017. Early application is not permitted. The standard permits the use of either the retrospective or cumulative effect transition method. The Company is evaluating the effect that ASU 2014-09 will have on its financial statements and related disclosures. The Company has not yet selected a transition method nor has it determined the effect of the standard on its ongoing financial reporting.
	In August 2014, the FASB issued ASU No. 2014-15, Presentation of Financial Statements - Going Concern (Subtopic 205-40): Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern (“ASU 2014-15”). The new guidance clarifies management’s responsibility to evaluate whether there is substantial doubt about an entity’s ability to continue as a going concern and to provide related footnote disclosure. ASU 2014-15 is effective for annual periods ending after December 15, 2016 and for annual periods and interim periods thereafter. Early adoption is permitted. The Company does not expect the adoption to have a material effect on the combined or consolidated financial statements.
	In November 2014, the FASB issued ASU No. 2014-16, Derivatives and Hedging, which clarifies how current GAAP should be interpreted in evaluating the economic characteristics and risks of a host contract in a hybrid financial instrument that is issued in the form of a share. The amendments in this Update are effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption, including adoption in an interim period, is permitted. The Update does not change the current criteria in GAAP for determining when separation of certain embedded derivative features in a hybrid financial instrument is required. The Company does not believe the adoption of this ASU to have a material impact on the combined and consolidated financial statements.
	In February 2015, the FASB issued ASU No. 2015-02, Consolidation (Topic 810) (“ASU 2015-02”). The new guidance changes the analysis that a reporting entity must perform to determine whether it should consolidate certain types of legal entities. ASU 2015-02 is effective for fiscal years, and for interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted, including adoption at an interim period. The Company has not yet determined the effect of the standard on its ongoing financial reporting.

Formation_and_Organization_Tab

Formation and Organization (Tables)	12 Months Ended
	Dec. 31, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Common Stock	At the consummation of the Offering, the Company's outstanding common stock is summarized in the table below:
		Shares of
		common stock
		Number	Percent Voting Interest
	Publicly held Class A common stock	3,000,000	21.82	%
	Class B common stock held by NuDevco Retail Holdings, LLC and NuDevco Retail, LLC	10,750,000	78.18	%
	Total	13,750,000	100	%

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consist of the following amounts as of (in thousands):
		Estimated	31-Dec-14			31-Dec-13
		useful
		lives (years)
	Information technology	2 – 5	$	25,588		$	22,529
	Leasehold improvements	2 – 5	4,568			4,568
	Furniture and fixtures	2 – 5	998			998
	Total		31,154			28,095
	Accumulated depreciation		(26,933		)	(23,278		)
	Property and equipment—net		$	4,221		$	4,817

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present assets and liabilities measured and recorded at fair value in the Company’s combined and consolidated balance sheets on a recurring basis by and their level within the fair value hierarchy as of (in thousands):
		Level 1			Level 2			Level 3		Total
	December 31, 2014
	Non-trading commodity derivative assets	$	—		$	80		$	—	$	80
	Trading commodity derivative assets	—			136			—		136
	Total commodity derivative assets	$	—		$	216		$	—	$	216
	Non-trading commodity derivative liabilities	$	(6,810	)	$	(5,017	)	$	—	$	(11,827	)
	Trading commodity derivative liabilities	(32		)	(145		)	—		(177		)
	Total commodity derivative liabilities	$	(6,842	)	$	(5,162	)	$	—	$	(12,004	)
		Level 1			Level 2			Level 3		Total
	December 31, 2013
	Non-trading commodity derivative assets	$	—		$	4,672		$	—	$	4,672
	Trading commodity derivative assets	—			3,405			—		3,405
	Total commodity derivative assets	$	—		$	8,077		$	—	$	8,077
	Non-trading commodity derivative liabilities	$	(563	)	$	(854	)	$	—	$	(1,417	)
	Trading commodity derivative liabilities	147			(581		)	—		(434		)
	Total commodity derivative liabilities	$	(416	)	$	(1,435	)	$	—	$	(1,851	)

Accounting_for_Derivative_Inst1

Accounting for Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Volumetric Underlying Derivative Transactions	The following table summarizes the net notional volume buy/(sell) of the Company’s open derivative financial instruments accounted for at fair value, broken out by commodity, as of:
	Non-trading
	Commodity	Notional		31-Dec-14			31-Dec-13
	Natural Gas	MMBtu		9,690			3,513
	Natural Gas Basis	MMBtu		2,710			373
	Electricity	MWh		607			465
	Trading
	Commodity	Notional		31-Dec-14			31-Dec-13
	Natural Gas	MMBtu		(155	)		2,259
	Natural Gas Basis	MMBtu		(56	)		1,443
Gains (Losses) on Derivative Instruments	Gains (losses) on derivative instruments, net and current period settlements on derivative instruments were as follows for the periods indicated (in thousands):
		Year Ended December 31,
		2014				2013			2012
	Loss on non-trading derivatives—cash flow hedges, net (including ineffectiveness gain (loss) of ($288) and $930 for the years ended December 31, 2013 and 2012, respectively.)	$	—			$	84		$	(17,942	)
	Gain (loss) on non-trading derivatives, net	(8,713		)		1,345			(1,074		)
	Gain (loss) on trading derivatives, net (including gain on trading derivatives—affiliates, net of $203, $1,509 and $506 for the years ended December 31, 2014, 2013 and 2012, respectively)	(5,822		)		5,138			(2,469		)
	Gain (loss) on derivatives, net	$	(14,535	)		$	6,567		$	(21,485	)
	Current period settlements on non-trading derivatives—cash flow hedges	$	—			$	(1,180	)	$	18,707
	Current period settlements on non-trading derivatives	(6,289		)		1,833			7,782
	Current period settlements on trading derivatives (including current period settlements on trading derivatives—affiliates, net of $315, ($1,780) and $87 for the years ended December 31, 2014, 2013 and 2012, respectively)	2,810				387			312
	Total current period settlements on derivatives	$	(3,479	)		$	1,040		$	26,801
Offsetting Assets	The following tables summarize the fair value and offsetting amounts of the Company’s derivative instruments by counterparty and collateral received or paid as of (in thousands):
		December 31, 2014
	Description	Gross Assets				Gross			Net Assets			Cash		Net Amount
						Amounts						Collateral		Presented
						Offset						Offset
	Non-trading commodity derivatives	$	3,642			$	(3,562	)	$	80		$	—	$	80
	Trading commodity derivatives	234				(98		)	136			—		136
	Total Current Derivative Assets	3,876				(3,660		)	216			—		216
	Non-trading commodity derivatives	313				(313		)	—			—		—
	Total Non-current Derivative Assets	313				(313		)	—			—		—
	Total Derivative Assets	$	4,189			$	(3,973	)	$	216		$	—	$	216
		December 31, 2013
	Description	Gross Assets				Gross			Net Assets			Cash		Net Amount
						Amounts						Collateral		Presented
						Offset						Offset
	Non-trading commodity derivatives	$	11,564			$	(6,898	)	$	4,666		$	—	$	4,666
	Trading commodity derivatives	3,949				(544		)	3,405			—		3,405
	Total Current Derivative Assets	15,513				(7,442		)	8,071			—		8,071
	Non-trading commodity derivatives	100				(94		)	6			—		6
	Trading commodity derivatives	14				(14		)	—			—		—
	Total Non-current Derivative Assets	114				(108		)	6			—		6
	Total Derivative Assets	$	15,627			$	(7,550	)	$	8,077		$	—	$	8,077
Offsetting Liabilities
		December 31, 2014
	Description	Gross				Gross			Net			Cash		Net Amount
		Liabilities				Amounts			Liabilities			Collateral		Presented
						Offset						Offset
	Non-trading commodity derivatives	$	(14,911	)		$	3,562		$	(11,349	)	$	—	$	(11,349	)
	Trading commodity derivatives	(275		)		98			(177		)	—		(177		)
	Total Current Derivative Liabilities	(15,186		)		3,660			(11,526		)	—		(11,526		)
	Non-trading commodity derivatives	(791		)		313			(478		)	—		(478		)
	Total Non-current Derivative Liabilities	(791		)		313			(478		)	—		(478		)
	Total Derivative Liabilities	$	(15,977	)		$	3,973		$	(12,004	)	$	—	$	(12,004	)
		December 31, 2013
	Description	Gross				Gross			Net			Cash		Net Amount
		Liabilities				Amounts			Liabilities			Collateral		Presented
						Offset						Offset
	Non-trading commodity derivatives	$	(8,289	)		$	6,898		$	(1,391	)	$	—	$	(1,391	)
	Trading commodity derivatives	(986		)		544			(442		)	—		(442		)
	Total Current Derivative Liabilities	(9,275		)		7,442			(1,833		)	—		(1,833		)
	Non-trading commodity derivatives	(120		)		94			(26		)	—		(26		)
	Trading commodity derivatives	(6		)		14			8			—		8
	Total Non-current Derivative Liabilities	(126		)		108			(18		)	—		(18		)
	Total Derivative Liabilities	$	(9,401	)		$	7,550		$	(1,851	)	$	—	$	(1,851	)
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the effects on the Company’s accumulated OCI balance attributable to cash flow hedge derivative instruments for the periods indicated (in thousands):
		Year Ended December 31,
		2014				2013
	Accumulated OCI balance, beginning of period	$	—			$	(2,536	)
	Deferred gain (loss) on cash flow hedge derivative instruments	—				2,620
	Reclassification of accumulated OCI net to income	—				(84		)
	Accumulated OCI balance, end of period	$	—			$	—

Equity_Tables

Equity (Tables)	12 Months Ended
	Dec. 31, 2014
Equity [Abstract]
Earnings Per Share	The following table presents the computation of earnings per share for the year ended December 31, 2014 (in thousands, except per share data):
		Year Ended
		31-Dec-14
	Net loss attributable to Spark Energy, Inc. stockholders	$	(54	)
	Basic weighted average Class A common shares outstanding (1)	3,000
	Basic EPS attributable to Spark Energy, Inc. stockholders	$	(0.02	)
	Net loss attributable to Spark Energy, Inc. stockholders	$	(54	)
	Effect of conversion of Class B common stock to shares of Class A common stock	—
	Diluted net loss attributable to Spark Energy, Inc. stockholders	(54		)
	Basic weighted average Class A common shares outstanding (1)	3,000
	Effect of dilutive Class B common stock (1)	—
	Effect of dilutive restricted stock units	—
	Diluted weighted average shares outstanding	3,000
	Diluted EPS attributable to Spark Energy, Inc. stockholders	$	(0.02	)
	(1) Based on outstanding shares for the period from the Offering date of August 1, 2014 to December 31, 2014.

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2014
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	The following table summarizes equity classified restricted stock unit activity and unvested restricted stock units for the year ended December 31, 2014:
		Number of Shares		Weighted Average Grant Date Fair Value
	Unvested at December 31, 2013	—		—
	Granted	264,150		$	18
	Dividend reinvestment issuances	4,334		14.01
	Vested	—		—
	Forfeited	(11,600	)	18
	Unvested at December 31, 2014	256,884		$	17.93
Restricted Stock Units, Liability Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	The following table summarizes liability classified restricted stock unit activity and unvested restricted stock units for the year ended December 31, 2014:
		Number of Shares		Weighted Average Reporting Date Fair Value
	Unvested at December 31, 2013	—		—
	Granted	122,000		$	14.09
	Dividend reinvestment issuances	2,093		14.09
	Vested	—		—
	Forfeited	—		—
	Unvested at December 31, 2014	124,093		$	14.09

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The (benefit) provision for income taxes included the following components:
	(in thousands)	2014			2013		2012
	Current:
	Federal	$	—		$	—	$	—
	State	173			56		46
	Total Current	173			56		46
	Deferred:
	Federal	(957		)	—		—
	State	(107		)	—		—
	Total Deferred	(1,064		)	—		—
	(Benefit) provision for income taxes	$	(891	)	$	56	$	46
Schedule of Effective Income Tax Rate Reconciliation	The following table reconciles the income tax benefit included in the combined and consolidated statement of operations with income tax expense that would result from application of the statutory federal tax rate, 34%, to loss before income tax expense:
	(in thousands)	2014
	Expected benefit at federal statutory rate	$	(1,753	)
	Increase (decrease) resulting from:
	Noncontrolling interest	1,451
	Corporate costs	(607		)
	State income taxes, net of federal income tax effect	69
	Other	(51		)
	Benefit for income taxes	$	(891	)
Schedule of Deferred Tax Assets	The components of the Company’s deferred tax assets as of December 31, 2014 are as follows:
	(in thousands)	2014
	Current deferred tax assets:
	Net operating loss carryforward	$	654
	Non-current deferred tax assets:
	Investment in Spark HoldCo	16,171
	Benefit of TRA liability	7,817
	Net operating loss carryforward	59
	Total non-current deferred tax assets	24,047
	Total deferred tax assets	$	24,701

Segment_Reporting_Tables

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2014
Segment Reporting [Abstract]
Reconciliation of Operating Profit (Loss) from Segments to Consolidated	Below is a reconciliation of retail gross margin to (loss) income before income tax expense.
			Years Ended December 31,
	(in thousands)		2014				2013				2012
	Reconciliation of Retail Gross Margin to (Loss)income before taxes
	(Loss) income before income tax expense		$	(5,156	)		$	31,468			$	26,139
	Interest and other income		(263		)		(353		)		(62		)
	Interest expense		1,578				1,714				3,363
	Operating Income		(3,841		)		32,829				29,440
	Depreciation and amortization		22,221				16,215				22,795
	General and administrative		45,880				35,020				47,321
	Less:
	Net asset optimization revenue		2,318				314				(1,136		)
	Net, Gains (losses) on non-trading derivative instruments		(8,713		)		1,429				(19,016		)
	Net, Cash settlements on non-trading derivative instruments		(6,289		)		653				26,489
	Retail Gross Margin		$	76,944			$	81,668			$	93,219
Schedule of Segment Reporting Information, by Segment	Financial data for business segments are as follows (in thousands):
	Year Ended December 31, 2014	Retail				Retail				Corporate				Eliminations			Total Spark Retail
		Electricity				Natural Gas				and Other
	Total Revenues	$	176,406			$	146,470			$	—			$	—		$	322,876
	Retail cost of revenues	149,452				109,164				—				—			258,616
	Less:
	Net asset optimization revenues	—				2,318				—				—			2,318
	Net, Gains (losses) on non-trading derivative instruments	(518		)		(8,195		)		—				—			(8,713		)
	Current period settlements on non-trading derivatives	(5,145		)		(1,144		)		—				—			(6,289		)
	Retail gross margin	$	32,617			$	44,327			$	—			$	—		$	76,944
	Total Assets	$	46,848			$	101,711			$	27,285			$	(37,447	)	$	138,397
	Year Ended December 31, 2013	Retail				Retail				Corporate				Eliminations			Total Spark Retail
		Electricity				Natural Gas				and Other
	Total Revenues	$	191,872			$	125,218			$	—			$	—		$	317,090
	Retail cost of revenues	149,885				83,141				—				—			233,026
	Less:
	Net asset optimization revenues	—				314				—				—			314
	Net, Gains (losses) on non-trading derivative instruments	1,336				93				—				—			1,429
	Current period settlements on non-trading derivatives	1,349				(696		)		—				—			653
	Retail gross margin	$	39,302			$	42,366			$	—			$	—		$	81,668
	Total Assets	$	41,879			$	87,985			$	953			$	(21,744	)	$	109,073
	Year Ended December 31, 2012	Retail				Retail				Corporate				Eliminations			Spark Retail
		Electricity				Natural Gas				and Other
	Total Revenues	$	256,357			$	122,705			$	—			$	—		$	379,062
	Retail cost of revenues	202,440				77,066				—				—			279,506
	Less:
	Net asset optimization revenues	—				(1,136		)		—				—			(1,136		)
	Net, Gains (losses) on non-trading derivative instruments	(17,400		)		(1,616		)		—				—			$	(19,016	)
	Current period settlements on non-trading derivatives	18,577				7,912				—				—			26,489
	Retail gross margin	$	52,740			$	40,479			$	—			$	—		$	93,219

Formation_and_Organization_Det

Formation and Organization (Details) (USD $)	0 Months Ended	12 Months Ended
	Aug. 01, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 17, 2012	30-May-08
Class of Stock [Line Items]
Percent of stock offered	21.82%
Net proceeds from the offering	$47,600,000
Payment of note payable to NuDevco		50,000	0	0
Offering costs	2,700,000	2,667,000	0	0
Revolving Credit Facility
Class of Stock [Line Items]
Line of credit facility, maximum borrowing capacity					30,000,000	35,000,000
Revolving Credit Facility | Senior Secured Revolving Credit Facility
Class of Stock [Line Items]
Line of credit facility, outstanding	10,000,000
Line of Credit | Revolving Credit Facility | Senior Secured Revolving Credit Facility
Class of Stock [Line Items]
Line of credit facility, maximum borrowing capacity	70,000,000
Common Class A
Class of Stock [Line Items]
Percent of stock offered	21.82%
Common stock, shares	3,000,000
Common stock, par value		$0.01	$0
Common Class B
Class of Stock [Line Items]
Percent of stock offered	78.18%
Common stock, shares	10,750,000
Common stock, par value	$0.01	$0.01	$0
Common Stock
Class of Stock [Line Items]
Percent of stock offered	100.00%
Common stock, shares	13,750,000
IPO | Common Class A
Class of Stock [Line Items]
Common stock, shares	3,000,000
Common stock, par value	$0.01
Common stock, price per share (usd per share)	$18
NuDevco Retail
Class of Stock [Line Items]
Ownership percentage transferred to affiliate	1.00%
NuDevco Retail | Common Class B
Class of Stock [Line Items]
Common stock, shares	137,500
Common stock, shares to be issued	137,500
Spark HoldCo | Common Class A
Class of Stock [Line Items]
Common stock, shares to be issued	2,997,222
Spark Energy, Inc
Class of Stock [Line Items]
Line of credit facility, outstanding	10,000,000
Repayments of debt	10,000,000
NuDevco Retail Holdings | Common Class A
Class of Stock [Line Items]
Common stock, shares to be issued	2,778
NuDevco Retail Holdings | Common Class B
Class of Stock [Line Items]
Common stock, shares	10,612,500
Common stock, shares to be issued	10,612,500
Affiliated Entity
Class of Stock [Line Items]
Line of credit facility, outstanding	29,000,000
Spark HoldCo | NuDevco Retail Holdings
Class of Stock [Line Items]
Investment in affiliate transferred	50,000
NuDevco Retail | Spark HoldCo
Class of Stock [Line Items]
Percent of stock offered	1.00%
NuDevco Retail Holdings | Spark HoldCo
Class of Stock [Line Items]
Percent of stock offered	77.18%
NuDevco Retail Holdings | Spark Energy, Inc
Class of Stock [Line Items]
Percent of stock offered	21.82%
Payment of note payable to NuDevco	$50,000
NuDevco Retail Holdings | Spark Energy, Inc | Common Class A
Class of Stock [Line Items]
Percent of stock offered	21.82%
Spark Energy, Inc | Spark HoldCo
Class of Stock [Line Items]
Percent of stock offered	21.82%

Basis_of_Presentation_and_Summ2

Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 01, 2014
	segment
Accounting Policies [Abstract]
Restricted cash	$707,000	$0
Allowance for doubtful accounts	8,000,000	1,200,000
Bad debt expense	10,164,000	3,101,000	1,835,000
Number of operating segments	2
Gross receipts taxes	3,000,000	3,500,000	5,100,000
Asset optimization revenue	284,600,000	192,400,000	248,600,000
Cost of revenues	$282,300,000	$192,100,000	$249,700,000
Class of Stock [Line Items]
Percent of stock offered				21.82%
Common Class A
Class of Stock [Line Items]
Percent of stock offered				21.82%
Common Class B
Class of Stock [Line Items]
Percent of stock offered				78.18%
NuDevco Retail Holdings | Spark Energy, Inc
Class of Stock [Line Items]
Percent of stock offered				21.82%
NuDevco Retail Holdings | Spark Energy, Inc | Common Class A
Class of Stock [Line Items]
Percent of stock offered				21.82%

Basis_of_Presentation_and_Summ3

Basis of Presentation and Summary of Significant Accounting Policies - Customer Acquisition Costs (Details) (USD $)	12 Months Ended			3 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Customer acquisition costs, current	$12,369,000	$4,775,000		$12,369,000
Customer acquisition costs, noncurrent	2,976,000	2,901,000		2,976,000
Amortization of customer acquisition costs	18,500,000	10,100,000	16,400,000
Impairment charges associated with capitalized customer acquisition costs	0	0	0
Capitalized Direct Advertising Costs
Finite-Lived Intangible Assets [Line Items]
Average useful life	2 years
Customer Contracts
Finite-Lived Intangible Assets [Line Items]
Intangible assets - customer acquisitions	1,500,000			1,500,000
Amortization period	3 years			3 years
California
Finite-Lived Intangible Assets [Line Items]
Amortization of customer acquisition costs	6,500,000
Massachusetts
Finite-Lived Intangible Assets [Line Items]
Amortization of customer acquisition costs	$200,000

Basis_of_Presentation_and_Summ4

Basis of Presentation and Summary of Significant Accounting Policies - Natural Gas Imbalances (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Other Current Assets
Gas Balance Arrangements [Line Items]
Gas balancing receivable (payable)	$1,400,000	$700,000
Other Current Liabilities
Gas Balance Arrangements [Line Items]
Gas balancing receivable (payable)	($600,000)	$0

Property_and_Equipment_Details

Property and Equipment (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Property and equipment, gross	31,154	$28,095
Accumulated depreciation	-26,933	-23,278
Property and equipmentbnet	4,221	4,817
Information technology
Property, Plant and Equipment [Line Items]
Property and equipment, gross	25,588	22,529
Information technology | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives (years)	2 years
Information technology | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives (years)	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,568	4,568
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives (years)	2 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives (years)	5 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	998	$998
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives (years)	2 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives (years)	5 years

Property_and_Equipment_Narrati

Property and Equipment - Narrative (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Depreciation	$3.70	$6.10	$6.40
Information technology
Property, Plant and Equipment [Line Items]
Assets not yet placed into service	$0.40	$1.30

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	3 Months Ended	12 Months Ended			0 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 17, 2012	Jul. 31, 2013	Aug. 01, 2014	Jan. 24, 2011	30-May-08
Line of Credit Facility [Line Items]
Deferred financing costs	$300,000	$300,000	$500,000
Amortization of deferred financing costs		600,000	700,000	900,000
Capitalized financing costs	300,000		100,000	300,000
Interest expense		1,578,000	1,714,000	3,363,000
NuDevco Retail Holdings | Spark HoldCo
Line of Credit Facility [Line Items]
Investment in affiliate transferred							50,000
Other Current Assets
Line of Credit Facility [Line Items]
Deferred financing costs	200,000	200,000	400,000
Other Noncurrent Assets
Line of Credit Facility [Line Items]
Deferred financing costs	100,000	100,000	100,000
Working Capital Facility
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity					70,000,000	80,000,000		150,000,000	177,500,000
Working capital facility outstanding			27,500,000
Working capital credit facility outstanding portion paid by affiliate							29,000,000
Letters of credit issued and outstanding	10,700,000	10,700,000	10,000,000				15,000,000
Fees on letters of credit issued and outstanding		400,000	500,000	600,000
Nonutilization fee					0.50%
Interest expense		400,000	300,000	1,300,000
Commitment fee percentage		0.50%
Commitment fee amount		100,000	200,000	500,000
Working Capital Facility | Eurodollar | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate					3.00%	3.00%
Working Capital Facility | Eurodollar | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate					3.75%	3.25%
Working Capital Facility | Base Rate | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate					2.00%	2.00%
Working Capital Facility | Base Rate | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate					2.75%	2.25%
Working Capital Facility | Cost of Funds Rate | Minimum
Line of Credit Facility [Line Items]
Basis spread on variable rate						2.50%
Working Capital Facility | Cost of Funds Rate | Maximum
Line of Credit Facility [Line Items]
Basis spread on variable rate						2.75%
Term Loan
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity					125,000,000			130,000,000	100,000,000
Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity					30,000,000				35,000,000
Revolving Credit Facility | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Line of credit facility, outstanding							10,000,000
Revolving Credit Facility | Senior Secured Revolving Credit Facility | Line of Credit
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity							70,000,000
Working capital facility outstanding	33,000,000	33,000,000
Contingent maximum borrowing capacity							$120,000,000
Reduction to interest rate if facility utilization is less than fifty percent							0.25%
Revolving Credit Facility | Minimum | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Commitment fee percentage							0.38%
Used capacity fee percentage							2.00%
Revolving Credit Facility | Maximum | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Commitment fee percentage							0.50%
Used capacity fee percentage							2.50%
Revolving Credit Facility | Eurodollar | Minimum | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate							2.75%
Revolving Credit Facility | Eurodollar | Maximum | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate							3.00%
Revolving Credit Facility | Base Rate | Minimum | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate							1.75%
Revolving Credit Facility | Base Rate | Maximum | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate							2.00%
Revolving Credit Facility | Cost of Funds Rate | Minimum | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate							2.25%
Revolving Credit Facility | Cost of Funds Rate | Maximum | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Basis spread on variable rate							2.50%
Revolving Credit Facility | Base Rate Plus Margin | Senior Secured Revolving Credit Facility
Line of Credit Facility [Line Items]
Stated percentage interest rate							2.00%
Letters Of Credit Outstanding More Than Two Business Days | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate		2.00%

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (Fair Value, Measurements, Recurring, USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$216	$8,077
Derivative liabilities	-12,004	-1,851
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	-6,842	-416
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	216	8,077
Derivative liabilities	-5,162	-1,435
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Non-trading Commodity Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	80	4,672
Derivative liabilities	-11,827	-1,417
Non-trading Commodity Contract | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	-6,810	-563
Non-trading Commodity Contract | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	80	4,672
Derivative liabilities	-5,017	-854
Non-trading Commodity Contract | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	0	0
Trading Commodity Contract
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	136	3,405
Derivative liabilities	-177	-434
Trading Commodity Contract | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	-32	147
Trading Commodity Contract | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	136	3,405
Derivative liabilities	-145	-581
Trading Commodity Contract | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	$0	$0

Accounting_for_Derivative_Inst2

Accounting for Derivative Instruments - Volumetric Underlying Derivative Transactions (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
	MMBTU	MMBTU
Not Designated as Hedging Instrument | Natural Gas
Derivatives, Fair Value [Line Items]
Net notional volume	9,690,000	3,513,000
Not Designated as Hedging Instrument | Natural Gas Basis
Derivatives, Fair Value [Line Items]
Net notional volume	2,710,000	373,000
Not Designated as Hedging Instrument | Electricity
Derivatives, Fair Value [Line Items]
Net notional volume	607,000	465,000
Designated as Hedging Instrument | Natural Gas
Derivatives, Fair Value [Line Items]
Net notional volume	-155,000	2,259,000
Designated as Hedging Instrument | Natural Gas Basis
Derivatives, Fair Value [Line Items]
Net notional volume	-56,000	1,443,000

Accounting_for_Derivative_Inst3

Accounting for Derivative Instruments - Gains (Losses) on Derivative Instruments (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Derivative Instruments, Gain (Loss) [Line Items]
Current period settlements on derivatives	($3,479)	$1,040	$26,801
Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on derivatives, net	-14,535	6,567	-21,485
Current period settlements on derivatives	-3,479	1,040	26,801
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on derivatives, net	-8,713	1,345	-1,074
Current period settlements on derivatives	-6,289	1,833	7,782
Not Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on derivatives, net	0	84	-17,942
Current period settlements on derivatives	0	-1,180	18,707
Ineffectiveness gain (loss)		-288	930
Designated as Hedging Instrument | Cash Flow Hedging
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on derivatives, net	-5,822	5,138	-2,469
Current period settlements on derivatives	2,810	387	312
Designated as Hedging Instrument | Cash Flow Hedging | Affiliated Entity
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on derivatives, net	203	1,509	506
Current period settlements on derivatives	$315	($1,780)	$87

Accounting_for_Derivative_Inst4

Accounting for Derivative Instruments - Offsetting Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Commodity Contract
Offsetting Assets [Line Items]
Gross Assets	$4,189	$15,627
Gross Amounts Offset	-3,973	-7,550
Net Assets	216	8,077
Cash Collateral Offset	0	0
Net Amount Presented	216	8,077
Commodity Contract, Current
Offsetting Assets [Line Items]
Gross Assets	3,876	15,513
Gross Amounts Offset	-3,660	-7,442
Net Assets	216	8,071
Cash Collateral Offset	0	0
Net Amount Presented	216	8,071
Non-trading Commodity Contract, Current
Offsetting Assets [Line Items]
Gross Assets	3,642	11,564
Gross Amounts Offset	-3,562	-6,898
Net Assets	80	4,666
Cash Collateral Offset	0	0
Net Amount Presented	80	4,666
Trading Commodity Contract, Current
Offsetting Assets [Line Items]
Gross Assets	234	3,949
Gross Amounts Offset	-98	-544
Net Assets	136	3,405
Cash Collateral Offset	0	0
Net Amount Presented	136	3,405
Commodity Contract, Noncurrent
Offsetting Assets [Line Items]
Gross Assets	313	114
Gross Amounts Offset	-313	-108
Net Assets	0	6
Cash Collateral Offset	0	0
Net Amount Presented	0	6
Non-trading Commodity Contract, Noncurrent
Offsetting Assets [Line Items]
Gross Assets	313	100
Gross Amounts Offset	-313	-94
Net Assets	0	6
Cash Collateral Offset	0	0
Net Amount Presented	0	6
Trading Commodity Contract, Noncurrent
Offsetting Assets [Line Items]
Gross Assets		14
Gross Amounts Offset		-14
Net Assets		0
Cash Collateral Offset		0
Net Amount Presented		$0

Accounting_for_Derivative_Inst5

Accounting for Derivative Instruments - Offsetting Liabilities (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Commodity Contract
Offsetting Liabilities [Line Items]
Gross Liabilities	($15,977)	($9,401)
Gross Amounts Offset	3,973	7,550
Net Liabilities	-12,004	-1,851
Cash Collateral Offset	0	0
Net Amount Presented	-12,004	-1,851
Commodity Contract, Current
Offsetting Liabilities [Line Items]
Gross Liabilities	-15,186	-9,275
Gross Amounts Offset	3,660	7,442
Net Liabilities	-11,526	-1,833
Cash Collateral Offset	0	0
Net Amount Presented	-11,526	-1,833
Non-trading Commodity Contract, Current
Offsetting Liabilities [Line Items]
Gross Liabilities	-14,911	-8,289
Gross Amounts Offset	3,562	6,898
Net Liabilities	-11,349	-1,391
Cash Collateral Offset	0	0
Net Amount Presented	-11,349	-1,391
Trading Commodity Contract, Current
Offsetting Liabilities [Line Items]
Gross Liabilities	-275	-986
Gross Amounts Offset	98	544
Net Liabilities	-177	-442
Cash Collateral Offset	0	0
Net Amount Presented	-177	-442
Commodity Contract, Noncurrent
Offsetting Liabilities [Line Items]
Gross Liabilities	-791	-126
Gross Amounts Offset	313	108
Net Liabilities	-478	-18
Cash Collateral Offset	0	0
Net Amount Presented	-478	-18
Non-trading Commodity Contract, Noncurrent
Offsetting Liabilities [Line Items]
Gross Liabilities	-791	-120
Gross Amounts Offset	313	94
Net Liabilities	-478	-26
Cash Collateral Offset	0	0
Net Amount Presented	-478	-26
Trading Commodity Contract, Noncurrent
Offsetting Liabilities [Line Items]
Gross Liabilities		-6
Gross Amounts Offset		14
Net Liabilities		8
Cash Collateral Offset		0
Net Amount Presented		$8

Accounting_for_Derivative_Inst6

Accounting for Derivative Instruments - Accumulated Other Comprehensive Income (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated OCI balance, beginning of period	$0	($2,536)
Deferred gain (loss) on cash flow hedge derivative instruments	0	2,620	-10,243
Reclassification of accumulated OCI net to income	0	-84	17,942
Accumulated OCI balance, end of period	$0	$0	($2,536)

Equity_Details

Equity (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
	vote
Class of Stock [Line Items]
Preferred stock authorized	20,000,000	0
Preferred stock shares issued	0	0
Preferred stock shares outstanding	0	0
Common Class A
Class of Stock [Line Items]
Common stock outstanding	3,000,000	0
Common stock voting rights	1
Common Class B
Class of Stock [Line Items]
Common stock outstanding	10,750,000	0
Common stock voting rights	1

Equity_Earnings_per_Share_Deta

Equity Earnings per Share (Details) (USD $)	7 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jul. 31, 2014	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income (loss) attributable to Spark Energy, Inc. stockholders	($21)	($54)		$31,412	$26,093
Basic weighted average Class A common shares outstanding (1)		3,000
Basic EPS attributable to Spark Energy, Inc. stockholders (in dollars per share)		($0.02)
Effect of conversion of Class B common stock to shares of Class A common stock		0
Diluted net loss attributable to Spark Energy, Inc. stockholders		($54)
Effect of dilutive restricted stock units		0
Diluted weighted average shares outstanding		3,000
Diluted EPS attributable to Spark Energy, Inc. stockholders (in dollars per share)		($0.02)
Common Class A
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Basic weighted average Class A common shares outstanding (1)		3,000	[1]
Common Class B
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive Class B common stock (1)		0	[1]
[1]	Based on outstanding shares for the period from the Offering date of August 1, 2014 to December 31, 2014.

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Number of maximum shares available for issuance	1,375,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance, shares	0
Granted, shares	264,150
Dividend reinvestment issuances, shares	4,334
Vested, shares	0
Forfeited, shares	-11,600
Ending balance, shares	256,884
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Beginning balance, weighted average grant date fair value	$0
Granted, weighted average grant date fair value	$18
Dividend reinvestment issuances, weighted average grant date fair value	$14.01
Vested, weighted average grant date fair value	$0
Forfeited, weighted average grant date fair value	$18
Ending balance, weighted average grant date fair value	$17.93
Forfeiture rate	6.00%
Unrecognized compensation expense	$4,100,000
Weighted average period	3 years 2 months 12 days
Restricted Stock Units | General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Stock based compensation expense	500,000	0	0
Restricted Stock Units, Liability Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning balance, shares	0
Granted, shares	122,000
Dividend reinvestment issuances, shares	2,093
Vested, shares	0
Forfeited, shares	0
Ending balance, shares	124,093
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Beginning balance, weighted average grant date fair value	$0
Granted, weighted average grant date fair value	$14.09
Dividend reinvestment issuances, weighted average grant date fair value	$14.09
Vested, weighted average grant date fair value	$0
Forfeited, weighted average grant date fair value	$0
Ending balance, weighted average grant date fair value	$14.09
Unrecognized compensation expense	1,400,000
Weighted average period	2 years 2 months 12 days
Restricted Stock Units, Liability Awards | Other Current Liabilities
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Other current liabilities related to restricted stock	100,000
Restricted Stock Units, Liability Awards | Other Noncurrent Liabilities
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Other noncurrent liabilities related to restricted stock	200,000
Restricted Stock Units, Liability Awards | General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Stock based compensation expense	$300,000	$0	$0
Non-Employee Director | Restricted Stock Units, Liability Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Award vesting period	9 months
Officer, Employee, and Employee of Affiliates | Restricted Stock Units | Service Years, Group One
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Award vesting period	3 years
Officer, Employee, and Employee of Affiliates | Restricted Stock Units | Service Years, Group Two
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Award vesting period	4 years

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
Income tax rate	17.30%
Statutory income rate	34.00%
Income tax penalties and interest expense	$0	$0	$0
Unrecognized tax benefits	0	0	0
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	1,900,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$1,800,000

Income_Taxes_Provision_Benefit

Income Taxes - Provision (Benefit) For Income Taxes (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	$0	$0	$0
State	173	56	46
Total Current	173	56	46
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Federal	-957	0	0
State	-107	0	0
Total Deferred	-1,064	0	0
Provision (benefit) for income taxes	($891)	$56	$46

Income_Taxes_Effective_Income_

Income Taxes - Effective Income Tax Rate Reconciliation (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Expected benefit at federal statutory rate	($1,753)
Noncontrolling interest	1,451
Corporate costs	-607
State income taxes, net of federal income tax effect	69
Other	-51
Provision (benefit) for income taxes	($891)	$56	$46

Income_Taxes_Deferred_Tax_Asse

Income Taxes - Deferred Tax Assets (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Income Tax Disclosure [Abstract]
Net operating loss carryforward	$654
Investment in Spark HoldCo	16,171
Benefit of TRA liability	7,817
Net operating loss carryforward	59
Total non-current deferred tax assets	24,047	0
Total deferred tax assets	$24,701

Transactions_with_Affiliates_D

Transactions with Affiliates (Details) (USD $)	0 Months Ended	12 Months Ended
	Aug. 01, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Related Party Transaction [Line Items]
Optimization Revenues - Affiliates		$2,318,000	$314,000	($1,136,000)
Cost of revenues		282,300,000	192,100,000	249,700,000
Number of additional years extended		3 years
Retail cost of revenues		258,616,000	233,026,000	279,506,000
General and administrative		45,880,000	35,020,000	47,321,000
Net capital distributions		2,584,000	0	0
Sale of property, plant and equipment-affiliates		0	0	577,000
Tax receivable agreement, net cash savings	15.00%
Affiliated Entity
Related Party Transaction [Line Items]
Accounts receivable-affiliates		1,200,000	6,800,000
Accounts payable-affiliates		1,000,000
Sale of property, plant and equipment-affiliates				600,000
Affiliated Entity | Marlin Processing Agreement
Related Party Transaction [Line Items]
Optimization Revenues - Affiliates			3,000,000	8,300,000
Affiliated Entity | Purchased Natural Gas From Affiliate
Related Party Transaction [Line Items]
Cost of revenues		30,300,000	17,700,000
Affiliated Entity | Purchased Natural Gas Sold To Affiliate
Related Party Transaction [Line Items]
Optimization Revenues - Affiliates		12,800,000	11,900,000	0
Affiliated Entity | Marlin Transportation Agreement
Related Party Transaction [Line Items]
Retail cost of revenues		100,000	100,000	300,000
Affiliated Entity | Electricity Sales To Affiliate
Related Party Transaction [Line Items]
Retail Revenues - Affiliates		2,200,000	4,000,000	1,400,000
Affiliated Entity | Affiliate Derivative Instruments
Related Party Transaction [Line Items]
Cost of revenues		600,000	-1,800,000	600,000
Affiliated Entity | Allocated Overhead Costs
Related Party Transaction [Line Items]
General and administrative		5,100,000	7,400,000	4,100,000
Affiliated Entity | Residual Commissions
Related Party Transaction [Line Items]
General and administrative		100,000	100,000	800,000
Majority Shareholder
Related Party Transaction [Line Items]
Net capital distributions		$36,400,000	$59,300,000	$10,400,000
NuDevco Retail Holdings and NuDevco Retail
Related Party Transaction [Line Items]
Tax receivable agreement, net cash savings	85.00%
Tax receivable agreement, deferral period	5 years
Tax receivable agreement, coverage percentage	130.00%
Tax receivable agreement, target dividend (usd per share)	0.3625

Segment_Reporting_Narrative_De

Segment Reporting - Narrative (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting [Abstract]
Asset optimization revenue	$284,600,000	$192,400,000	$248,600,000
Cost of revenues	$282,300,000	$192,100,000	$249,700,000
Retail Natural Gas | Customer
Segment Reporting Information [Line Items]
Number of significant customers		1	1
Number of significant suppliers	1
Retail Natural Gas | Customer | Sales Revenue
Segment Reporting Information [Line Items]
Number of significant customers	1	1	1
Retail Electricity | Customer
Segment Reporting Information [Line Items]
Number of significant suppliers	3	1	0

Segment_Reporting_Reconciliati

Segment Reporting - Reconciliation (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting [Abstract]
(Loss) income before income tax expense	($5,156)	$31,468	$26,139
Interest and other income	-263	-353	-62
Interest expense	1,578	1,714	3,363
Operating Income	-3,841	32,829	29,440
Depreciation and amortization	22,221	16,215	22,795
General and administrative	45,880	35,020	47,321
Optimization Revenues - Affiliates	2,318	314	-1,136
Net, Gains (losses) on non-trading derivative instruments	-8,713	1,429	-19,016
Net, Cash settlements on non-trading derivative instruments	-6,289	653	26,489
Retail Gross Margin	$76,944	$81,668	$93,219

Segment_Reporting_Financial_Da

Segment Reporting - Financial Data (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Total Revenues	$322,876,000	$317,090,000	$379,062,000
Retail cost of revenues	258,616,000	233,026,000	279,506,000
Optimization Revenues - Affiliates	2,318,000	314,000	-1,136,000
Net, Gains (losses) on non-trading derivative instruments	-8,713,000	1,429,000	-19,016,000
Current period settlements on non-trading derivatives	-6,289,000	653,000	26,489,000
Retail gross margin	76,944,000	81,668,000	93,219,000
Total Assets	138,397,000	109,073,000
Operating Segments | Retail Electricity
Segment Reporting Information [Line Items]
Total Revenues	176,406,000	191,872,000	256,357,000
Retail cost of revenues	149,452,000	149,885,000	202,440,000
Optimization Revenues - Affiliates	0	0	0
Net, Gains (losses) on non-trading derivative instruments	-518,000	1,336,000	-17,400,000
Current period settlements on non-trading derivatives	-5,145,000	1,349,000	18,577,000
Retail gross margin	32,617,000	39,302,000	52,740,000
Total Assets	46,848,000	41,879,000
Operating Segments | Retail Natural Gas
Segment Reporting Information [Line Items]
Total Revenues	146,470,000	125,218,000	122,705,000
Retail cost of revenues	109,164,000	83,141,000	77,066,000
Optimization Revenues - Affiliates	2,318,000	314,000	-1,136,000
Net, Gains (losses) on non-trading derivative instruments	-8,195,000	93,000	-1,616,000
Current period settlements on non-trading derivatives	-1,144,000	-696,000	7,912,000
Retail gross margin	44,327,000	42,366,000	40,479,000
Total Assets	101,711,000	87,985,000
Corporate and Other
Segment Reporting Information [Line Items]
Total Revenues	0	0	0
Retail cost of revenues	0	0	0
Optimization Revenues - Affiliates	0	0	0
Net, Gains (losses) on non-trading derivative instruments	0	0	0
Current period settlements on non-trading derivatives	0	0	0
Retail gross margin	0	0	0
Total Assets	27,285,000	953,000
Eliminations
Segment Reporting Information [Line Items]
Total Revenues	0	0	0
Retail cost of revenues	0	0	0
Optimization Revenues - Affiliates	0	0	0
Net, Gains (losses) on non-trading derivative instruments	0	0	0
Current period settlements on non-trading derivatives	0	0	0
Retail gross margin	0	0	0
Total Assets	($37,447,000)	($21,744,000)

Customer_Acquisitions_Details

Customer Acquisitions (Details) (USD $)	3 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Number of purchase agreements	2
Variable rate electricity contracts	13,400	13,400
Customer Contracts
Finite-Lived Intangible Assets [Line Items]
Purchase price	$2.20	$2.20
Amortization period	3 years	3 years
Intangible assets paid and capitalized	$1.50	$1.50

Subsequent_Events_Details

Subsequent Events (Details) (Subsequent Event, USD $)	0 Months Ended
In Millions, except Per Share data, unless otherwise specified	Feb. 16, 2015	Mar. 03, 2015
		contract
Subsequent Event [Line Items]
Residential and commercial natural gas contracts		33,500
Purchase price		$2.80
Common Class A
Subsequent Event [Line Items]
Dividends	$0.36

Uncategorized_Items

Uncategorized Items
[us-gaap_SharesIssued]	3,000,000	10,750,000
[us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest]			0	30,000	108,000