Deferred Compensation Plan	9 Months Ended
Deferred Compensation Plan	Sep. 30, 2011
Deferred Compensation Plan [Abstract]
Deferred Compensation Plan	11. Deferred Compensation Plan On September 2, 2011, the Board of Directors approved the Spectrum Pharmaceuticals, Inc. Deferred Compensation Plan (the “Plan”). The Plan is intended to comply with the requirements of Section 409A of the Internal Revenue Code of 1986, as amended. The Plan will be administered by the Compensation Committee of the board of directors, or a designee or designees of the Compensation Committee. The Plan is intended to be an unfunded plan which is maintained primarily to provide deferred compensation benefits for a select group of our employees including management, as selected by the Plan administrator (the “Participants”). Under the Plan, we will provide the Participants with the opportunity to make annual elections to defer up to a specified amount or percentage of their eligible cash compensation, as established by the Plan administrator, and we have the option to make discretionary contributions. At September 30, 2011, deferrals and contributions totaling $95,236 are included in other accrued obligations in the accompanying condensed consolidated balance sheet.

The entire disclosure for compensation costs, including compensated absences accruals, compensated absences liability, deferred compensation arrangements and income statement compensation items. Deferred compensation arrangements may include a description of an arrangement with an individual employee, which is generally an employment contract between the entity and a selected officer or key employee containing a promise by the employer to pay certain amounts at designated future dates, usually including a period after retirement, upon compliance with stipulated requirements. This type of arrangement is distinguished from broader based employee benefit plans as it is usually tailored to the employee. Disclosure also typically includes the amount of related compensation expense recognized during the reporting period, the number of shares (units) issued during the period under such arrangements, and the carrying amount as of the balance sheet date of the related liability.