Acquisitions	12 Months Ended
Dec. 31, 2016
Business Combinations [Abstract]
Acquisitions	Acquisitions Synchronite LLC On June 2, 2014, the Company acquired Synchronite LLC (“Synchronite”), a German based start-up that provides co-browsing technology. The transaction was accounted for under the purchase method of accounting and, accordingly, the operating results of Synchronite were included in the Company’s consolidated results of operations from the date of acquisition. The allocation of the total purchase price of approximately $4.1 million was based upon the estimated fair value of Synchronite's net tangible and identifiable intangible assets as of the date of acquisition. The total acquisition costs incurred were approximately $0.4 million and are included in general and administrative expenses in the Company’s consolidated statements of operations. Of the total purchase price, $45,000 was allocated to the net book values of the acquired assets and assumed liabilities. The historical carrying amounts of such assets and liabilities approximated their fair values. All receivables acquired are expected to be collectible. The purchase price includes approximately $2.7 million of goodwill and approximately $1.5 million of intangible assets. The goodwill will be deductible for tax purposes. The intangible assets are being amortized over their expected period of benefit. The purchase price includes $1.8 million of potential earn-out consideration for the shareholders if complete product integration is achieved. The earn-out is payable in shares of LivePerson common stock and cash. The Company recorded the contingent earn-out as part of the purchase price. In accordance with ASC 480, the Company has classified this amount as a liability and the amount is included in accrued expenses in the December 31, 2016 consolidated balance sheet, due to the variable number of shares that will be issued if and when the targets are achieved. During the year ended December 31, 2015, the Company made $1.6 million of payments. The ending balance at December 31, 2016 is $0.2 million. The Company will continue to assess the earn-out calculation in future periods and any future adjustments will affect operating income. Contact At Once!, LLC On November 7, 2014, the Company acquired Contact At Once!, LLC (“CAO!”), a software company with a cloud-based platform that instantly connects consumers with businesses through instant messaging, text messaging, chat, social media and video over the internet for consumer-to-business sales conversions. The transaction was accounted for under the purchase method of accounting and, accordingly, the operating results of CAO! were included in the Company’s consolidated results of operations from the date of acquisition. The allocation of the total purchase price of approximately $67.0 million, which includes approximately $42.8 million in cash, approximately $20.0 million in shares of common stock and approximately $4.2 million of potential earn-out consideration in cash, was based upon the estimated fair value of CAO!'s net tangible and identifiable intangible assets as of the date of acquisition. The historical carrying amounts of such assets and liabilities approximated their fair values. All receivables acquired are expected to be collectible. The purchase price included approximately $45.1 million of goodwill and approximately $20.4 million of intangible assets. The goodwill will be deductible for tax purposes. The intangible assets are being amortized over their expected period of benefit. The purchase price includes $4.2 million of potential earn-out consideration for the shareholders if certain targeted financial, strategic and integration objectives is achieved. The earn-out is payable in cash. The Company recorded the contingent earn-out as part of the purchase price. During the year ended December 31, 2015, the Company assessed this earn-out and recorded a $3.2 million fair value re-measurement adjustment, which was recorded in loss from operations as a decrease in general and administrative expenses. During the year ended December 31, 2016, the Company made cash payments of $0.2 million. There is no remaining liability included in accrued expenses relating to this contingent earn-out as of December 31, 2016.

Acquisitions

12 Months Ended

Dec. 31, 2016

Synchronite LLC

On June 2, 2014, the Company acquired Synchronite LLC (“Synchronite”), a German based start-up that provides co-browsing technology. The transaction was accounted for under the purchase method of accounting and, accordingly, the operating results of Synchronite were included in the Company’s consolidated results of operations from the date of acquisition.

The allocation of the total purchase price of approximately $4.1 million was based upon the estimated fair value of Synchronite's net tangible and identifiable intangible assets as of the date of acquisition. The total acquisition costs incurred were approximately $0.4 million and are included in general and administrative expenses in the Company’s consolidated statements of operations. Of the total purchase price, $45,000 was allocated to the net book values of the acquired assets and assumed liabilities. The historical carrying amounts of such assets and liabilities approximated their fair values. All receivables acquired are expected to be collectible. The purchase price includes approximately $2.7 million of goodwill and approximately $1.5 million of intangible assets. The goodwill will be deductible for tax purposes. The intangible assets are being amortized over their expected period of benefit. The purchase price includes $1.8 million of potential earn-out consideration for the shareholders if complete product integration is achieved. The earn-out is payable in shares of LivePerson common stock and cash. The Company recorded the contingent earn-out as part of the purchase price. In accordance with ASC 480, the Company has classified this amount as a liability and the amount is included in accrued expenses in the December 31, 2016 consolidated balance sheet, due to the variable number of shares that will be issued if and when the targets are achieved. During the year ended December 31, 2015, the Company made $1.6 million of payments. The ending balance at December 31, 2016 is $0.2 million. The Company will continue to assess the earn-out calculation in future periods and any future adjustments will affect operating income.

Contact At Once!, LLC

On November 7, 2014, the Company acquired Contact At Once!, LLC (“CAO!”), a software company with a cloud-based platform that instantly connects consumers with businesses through instant messaging, text messaging, chat, social media and video over the internet for consumer-to-business sales conversions. The transaction was accounted for under the purchase method of accounting and, accordingly, the operating results of CAO! were included in the Company’s consolidated results of operations from the date of acquisition.

The allocation of the total purchase price of approximately $67.0 million, which includes approximately $42.8 million in cash, approximately $20.0 million in shares of common stock and approximately $4.2 million of potential earn-out consideration in cash, was based upon the estimated fair value of CAO!'s net tangible and identifiable intangible assets as of the date of acquisition. The historical carrying amounts of such assets and liabilities approximated their fair values. All receivables acquired are expected to be collectible. The purchase price included approximately $45.1 million of goodwill and approximately $20.4 million of intangible assets. The goodwill will be deductible for tax purposes. The intangible assets are being amortized over their expected period of benefit. The purchase price includes $4.2 million of potential earn-out consideration for the shareholders if certain targeted financial, strategic and integration objectives is achieved. The earn-out is payable in cash. The Company recorded the contingent earn-out as part of the purchase price. During the year ended December 31, 2015, the Company assessed this earn-out and recorded a $3.2 million fair value re-measurement adjustment, which was recorded in loss from operations as a decrease in general and administrative expenses. During the year ended December 31, 2016, the Company made cash payments of $0.2 million. There is no remaining liability included in accrued expenses relating to this contingent earn-out as of December 31, 2016.