Basis of Presentation (Policies)	9 Months Ended
Basis of Presentation (Policies)	Sep. 30, 2014
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim unaudited condensed combined and consolidated financial statements (“interim statements”) of the Company have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC"). The preparation of the financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent liabilities at the date of the interim financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Effects on the business, financial condition and results of operations resulting from revisions to estimates are recognized when the facts that give rise to the revision become known. The information furnished herein reflects all normal recurring adjustments which are, in the opinion of management, necessary for a fair presentation of the condensed combined and consolidated financial statements. Operating results for the three and nine months ended September 30, 2014 are not necessarily indicative of the results which may be expected for the full year or for any interim period. The accompanying interim unaudited condensed 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 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 interim unaudited condensed 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 unaudited condensed consolidated financial statements subsequent to the Offering are presented on a consolidated basis and include all wholly-owned and controlled subsidiaries.
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 condensed 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 condensed combined and consolidated statements of operations with a corresponding accounts receivable—affiliates recorded in the condensed 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 condensed combined and consolidated statements of operations with a corresponding accounts receivable—affiliate or accounts payable—affiliate in the condensed combined and consolidated balance sheets. See Note 11 “Transactions with Affiliates” for further discussion.
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 condensed combined and consolidated financial statements. See Note 13 "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.