Accrued Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Payroll and other employee related costs	$ 10,893	$ 15,373
Professional services and consulting and other vendor fees	9,730us-gaap_AccruedProfessionalFeesCurrent	9,258us-gaap_AccruedProfessionalFeesCurrent
Sales commissions	1,448us-gaap_AccruedSalesCommissionCurrent	3,268us-gaap_AccruedSalesCommissionCurrent
Contingent earnout (see Notes 8 and 9)	6,591lpsn_ContingentEarnoutLiability	6,940lpsn_ContingentEarnoutLiability
Other	2,869us-gaap_OtherAccruedLiabilitiesCurrent	2,933us-gaap_OtherAccruedLiabilitiesCurrent
Total	$ 31,531us-gaap_AccruedLiabilitiesCurrent	$ 37,772us-gaap_AccruedLiabilitiesCurrent

Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Carrying value as of the balance sheet date of obligations incurred through that date and payable for sales commissions. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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