Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. 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 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 are expected to become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in making this assessment. The Company includes interest accrued on the underpayment of income taxes in interest expense and penalties, if any, related to unrecognized tax benefits in general and administrative expenses. The Company recorded a valuation allowance against its U.S. deferred tax asset as it considered its cumulative loss in recent years as a significant piece of negative evidence. Since valuation allowances are evaluated on a jurisdiction by jurisdiction basis, the Company believes that the deferred tax assets related to LivePerson Australia, LivePerson UK, Kasamba (Israel), LivePerson Japan and LivePerson Ltd. (Israel) are more likely than not to be realized as these jurisdictions have positive cumulative pre-tax book income after adjusting for permanent and one-time items. During the year ended December 31, 2020, there was an increase in the valuation recorded of $6.9 million. For the three months ended September 30, 2021, the Company recorded a tax provision of $2.5 million. This amount consists of a tax provision for the period of $2.7 million on operating earnings for the period offset by a tax benefit of $0.2 million related to stock compensation deductions for LivePerson UK Ltd. and LivePerson Ltd. (Israel). For the nine months ended September 30, 2021, the Company recorded a tax provision of $2.3 million. This amount consists of a tax provision of $4.3 million on operating earnings offset by a tax benefit of $1.5 million for the release of a reserve of uncertain tax benefits recorded against deferred tax assets related to Israeli stock compensation deductions and a benefit of $0.5 million for excess tax benefits from stock compensation. A statutory rate change in the United Kingdom was enacted during the nine months ended September 30, 2021. Effective April 1, 2023, the tax rate will increase from 19% to 25%. During the period, the Company assessed the impact of the rate change and concluded that it is immaterial to its deferred taxes. The Company had a valuation allowance on certain deferred tax assets for the year ended December 31, 2020 of $55.4 million. Inherent in the Company’s 2021 annual effective tax rate is an estimated increase in the valuation allowance of $31.2 million, all of which will be recorded as an expense. During 2020, an increase in the valuation allowance in the amount of $35.1 million was recorded as an expense and a decrease of $28.2 million related to convertible notes was charged to equity. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) was signed into law making several changes to the Internal Revenue Code. The changes include, but are not limited to: increasing the limitation on the amount of deductible interest expense, allowing companies to carryback certain net operating losses, and increasing the amount of net operating loss carryforwards that corporations can use to offset taxable income. As a result of the CARES Act, the Company filed refund claims relating to prior years totaling $0.6 million.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.