Share Based Compensation Arrangement by Share Based Payment Award, Options, Expiration Term

No definition available.

Name:	lpsn_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationTerm
Namespace Prefix:	lpsn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-based Compensation Arrangement By Share-based Payment Award, Fair Value Assumptions, Period Used To Determine Volatility

+ References

No definition available.

+ Details

Name:	lpsn_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsPeriodUsedToDetermineVolatility
Namespace Prefix:	lpsn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Stock Repurchase Program, Increase To Authorized Amount

+ References

No definition available.

+ Details

Name:	lpsn_StockRepurchaseProgramIncreaseToAuthorizedAmount
Namespace Prefix:	lpsn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Aggregate number of common shares reserved for future issuance.

+ References

+ Details

Name:	us-gaap_CommonStockCapitalSharesReservedForFutureIssuance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_CommonStockNumberOfSharesParValueAndOtherDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Face amount or stated value per share of common stock.

+ References

+ Details

Name:	us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

+ References

+ Details

Name:	us-gaap_CommonStockSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

+ References

+ Details

Name:	us-gaap_CommonStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

+ Details

Name:	us-gaap_CommonStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Unrecognized cost of unvested share-based awards, other than options, awarded to employees as compensation.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_PreferredStockNumberOfSharesParValueAndOtherDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

+ References

+ Details

Name:	us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

+ References

+ Details

Name:	us-gaap_PreferredStockSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

+ References

+ Details

Name:	us-gaap_PreferredStockSharesIssued
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

+ References

+ Details

Name:	us-gaap_PreferredStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of additional shares authorized for issuance under an established share-based compensation plan.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfAdditionalSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=96867065&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

+ Details

Name:	us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of stock issued as a result of the exercise of stock options.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramAuthorizedAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount remaining of a stock repurchase plan authorized.

+ References

No definition available.

+ Details

Name:	us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21463-112644

+ Details

Name:	us-gaap_StockRepurchasedDuringPeriodShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_EmployeeStockOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AwardTypeAxis=us-gaap_RestrictedStockUnitsRSUMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=lpsn_NineteenNinetyEightPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=lpsn_TwoThousandPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=lpsn_NineteenNinetyEightAndTwoThousandPlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=lpsn_TwoThousandNinePlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=lpsn_TwoThousandNinePlanAmendedMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=lpsn_EmployeeStockPurchasePlanTwentyTenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PlanNameAxis=lpsn_A2018PlanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ShareRepurchaseProgramAxis=lpsn_A2012StockRepurchaseProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Stockholders' Equity (Narrative) (Details) - USD ($)				3 Months Ended		6 Months Ended
Stockholders' Equity (Narrative) (Details) - USD ($)	Apr. 25, 2018	Apr. 30, 2017	Jun. 07, 2012	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Jan. 31, 2018	Dec. 31, 2017	Nov. 21, 2016	Feb. 16, 2016	Jul. 23, 2014	Mar. 13, 2014	Dec. 10, 2012	Jun. 30, 2010
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Common stock, shares authorized (in shares)				100,000,000		100,000,000			100,000,000
Common stock, shares issued (in shares)				62,366,602		62,366,602			59,663,969
Common stock, shares outstanding (in shares)				60,537,707		60,537,707			59,663,969
Common stock, par value (in dollars per share)				$ 0.001		$ 0.001			$ 0.001
Preferred Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Preferred stock, shares authorized (in shares)				5,000,000		5,000,000			5,000,000
Preferred stock, shares issued (in shares)				0		0			0
Preferred stock, shares outstanding (in shares)				0		0			0
Preferred stock, par value (in dollars per share)				$ 0.001		$ 0.001			$ 0.001
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchased during period (in shares)						93,750
Stock repurchase program, remaining authorized repurchase amount				$ 17,100,000		$ 17,100,000
Per share weighed average fair value of stock options granted during the period (in dollars per share)				$ 8.15	$ 3.55	$ 6.26	$ 3.50
Dividend yield				0.00%	0.00%	0.00%	0.00%
Expected life				5 years	5 years	5 years	5 years
Period used to determine volatility						5 years
Total value of stock options exercised						$ 12,100,000
Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested share-based compensation arrangements				$ 17,200,000		$ 17,200,000
Weighted average recognition period of unrecognized compensation cost						3 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost related to nonvested share-based compensation arrangements				$ 33,400,000		$ 33,400,000
Weighted average recognition period of unrecognized compensation cost						3 years
Vesting period						4 years
1998 Plan \| Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock available for issuance (up to)				5,850,000		5,850,000
2000 Plan \| Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in number of shares of common stock available for issuance						4,150,000
1998 and 2000 Plan \| Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock available for issuance (up to)				10,000,000		10,000,000
2009 Plan \| Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in number of shares of common stock available for issuance						6,000,000
2009 Plan, Amended \| Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock available for issuance (up to)		27,817,744		2,200,000		2,200,000
Increase in number of shares of common stock available for issuance		4,000,000	4,250,000
Stock option term						10 years
2010 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock available for issuance (up to)		2,000,000		900,000		900,000									1,000,000
Increase in number of shares of common stock available for issuance		1,000,000
2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock available for issuance (up to)	2,000,000							1,500,000
Increase in number of shares of common stock available for issuance	500,000
2018 Plan \| Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance				600,000		600,000
2012 Stock Repurchase Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock repurchase program, authorized amount										$ 74,000,000.0	$ 64,000,000.0	$ 50,000,000.0	$ 40,000,000.0	$ 30,000,000.0
Increase to authorized amount											$ 14,000,000