Basis of presentation (Policies)	3 Months Ended
Basis of presentation (Policies)	Mar. 31, 2016
Fair Value Disclosures [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 generally accepted accounting principles in the U.S. (“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, 2015. 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 months ended March 31, 2016 are not necessarily indicative of the results to be expected for the full year. Certain amounts recorded in the prior period unaudited condensed consolidated financial statements presented have been reclassified to conform to the current period financial statement presentation. These reclassifications had no effect on previously reported operating results.
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, 2015 are described in the Company’s Annual Report on Form 10-K, filed with the Securities and Exchange Commission on February 26, 2016. There have been no material changes with respect to the Company’s significant accounting policies subsequent to December 31, 2015.
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	SAR awards are accounted for as equity, in accordance with ASC 718, Compensation — Stock Compensation, which states that options or similar instruments on shares shall be classified as liabilities if either the underlying shares are classified as liabilities or the entity can be required under any circumstance to settle the option or similar instrument by transferring cash or other assets. The Company’s underlying shares are classified as equity, and under the terms of the SAR Award Agreement, the Company must settle the exercised portion of the SAR in shares of the Company’s common stock. As such, the Company has accounted for the SAR as equity. 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. 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.

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.