Basis of presentation (Policies)	9 Months Ended
Basis of presentation (Policies)	Sep. 30, 2014
Earnings Per Share [Abstract]
Unaudited condensed consolidated financial statements	*Unaudited condensed consolidated financial statements* The unaudited condensed consolidated financial statements of Power Solutions International, Inc. present information in accordance with GAAP, have been prepared pursuant to the rules and regulations of the SEC for interim financial reporting and, in the opinion of management, reflect all normal and recurring adjustments necessary to present fairly the interim periods of the unaudited condensed consolidated financial position, results of operations and cash flows of the Company and its wholly-owned subsidiaries for the periods presented. These unaudited condensed consolidated financial statements should be read in conjunction with, and have been prepared in conformity with the accounting principles reflected in, the consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2013. As these financial statements have been prepared pursuant to the rules and regulations of the SEC, certain information and disclosures normally included in annual financial statements and related notes prepared in accordance with GAAP have been condensed or omitted. The results of operations for the three and nine months ended September 30, 2014 are not necessarily indicative of the results to be expected for the full year.
Principles of consolidation	*Principles of consolidation* The unaudited condensed consolidated financial statements presented herein include the accounts of Power Solutions International, Inc. and its direct and indirect wholly owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Significant accounting policies	*Significant accounting policies* The Company’s significant accounting policies as of December 31, 2013 are described in the Company’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 28, 2014. There have been no material changes with respect to the Company’s significant accounting policies subsequent to December 31, 2013, with the exception of goodwill and other intangibles. Pursuant to the acquisition of 3PI, during the second quarter of 2014, the Company adopted a significant accounting policy for goodwill and other intangible assets. See Note 2, “Acquisition of Professional Power Products, Inc.”, for further discussion.
Earnings Per Share	The Company computes earnings (loss) per share by applying the guidance stated in ASC 260, Earnings per Share.
Distinguishing Liabilities from Equity	The Company analyzes financial instruments with features of both liabilities and equity under ASC 480, Distinguishing Liabilities from Equity
Derivatives and Hedging	The Company analyzes financial instruments with features of both liabilities and equity under ASC 480, Distinguishing Liabilities from Equity and ASC 815, Derivatives and Hedging.
Compensation - Stock Compensation	ASC 718, Compensation — Stock Compensation, was utilized in order to estimate the fair value of the SAR. The term “fair value” has been defined in Note 8, “Fair value of financial instruments.” ASC 718 requires an entity to measure the cost of employee services received in exchange for an award of equity instruments based on the fair value of the award as of the grant date. That cost is then recognized over the period during which an employee is required to provide service in exchange for the award. ASC 718-10-55-72 provides that, if vesting (or exercisability) of an award is based on satisfying both a market condition and a performance or service condition and it is probable that the performance or service condition will be satisfied, the initial estimate of the service period is the longest of the explicit, implicit or derived service period. The Company has computed compensation expense by applying the guidance stated in ASC 718, on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in-substance, multiple awards (graded vesting attribution method). Since, as noted above, the SAR granted by the Company includes both a market and service condition, the Company used the longest of the periods to define its requisite service period in each separately vesting portion or tranche. To determine the derived service period associated with the SAR’s market condition, the Company performed a Monte Carlo analysis in order to estimate the likely timeframe until the Company’s public equivalent value would exceed its aggregate exercise price over a period of seven days within a period of 10 or fewer trading days (i.e. the value at which the per share value of the Company’s equity exceeds $22.07). Based on the results of this analysis, the derived service period associated with the SAR’s market condition was determined to be 1.78 years. Thus, compensation expense for the first tranche was computed on a straight-line basis over the derived service period of 1.78 years. The second and third tranches were computed on a straight-line basis over the explicit service period.

Disclosure of accounting policy for its derivative instruments and hedging activities.

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Disclosure of accounting policy for computing basic and diluted earnings or loss per share for each class of common stock and participating security. Addresses all significant policy factors, including any antidilutive items that have been excluded from the computation and takes into account stock dividends, splits and reverse splits that occur after the balance sheet date of the latest reporting period but before the issuance of the financial statements.

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Disclosure of accounting policy for the equity method of accounting for investments in common stock or other interests including unconsolidated subsidiaries, corporate joint ventures, noncontrolling interests in real estate ventures, limited partnerships, and limited liability companies. The accounting policy may include information such as: (1) initially recording an investment in the stock of an investee at cost; (2) adjusting the carrying amount of the investment to recognize the investor's share of the earnings or losses of the investee after the date of acquisition; and (3) adjustments to reflect the investor's share of changes in the investee's capital (dividends). This disclosure may also include a detailed description of the policy for determining the amount of equity method losses recognized after an investment has been reduced to zero as a result of previous losses, reasons for not using the equity method when the investor company owns 20 percent or more of the voting stock of the investee's company (including identification of the significant investee), reasons for using the equity method when the ownership percentage is less than 20 percent, and discussion of recognition of equity method losses when an investor's total investment in an investee includes, in addition to an investment in common stock, other investments such as preferred stock and loans to the investee. An entity also may describe how such investments are assessed for impairment.

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The entire disclosure for the organization, consolidation and basis of presentation of financial statements disclosure, and significant accounting policies of the reporting entity. May be provided in more than one note to the financial statements, as long as users are provided with an understanding of (1) the significant judgments and assumptions made by an enterprise in determining whether it must consolidate a VIE and/or disclose information about its involvement with a VIE, (2) the nature of restrictions on a consolidated VIE's assets reported by an enterprise in its statement of financial position, including the carrying amounts of such assets, (3) the nature of, and changes in, the risks associated with an enterprise's involvement with the VIE, and (4) how an enterprise's involvement with the VIE affects the enterprise's financial position, financial performance, and cash flows. Describes procedure if disclosures are provided in more than one note to the financial statements.

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