Equity Incentive Plan - Assumptions used to estimate fair value of performance unit awards (Details) - March 5, 2020	9 Months Ended
Sep. 30, 2020 $ / shares
Performance unit awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value per performance share award (USD per share)	$ 11.02
Expense per performance share award (USD per share)	$ 11.02
Performance unit awards with market criteria
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining performance period	2 years 3 months 3 days
Risk-free interest rate (as a percent)	0.13%
Dividend yield (as a percent)	0.00%
Expected volatility (as a percent)	119.46%
Closing stock price (USD per share)	$ 9.80
Fair value per performance share award (USD per share)	11.63
Expense per performance share award (USD per share)	11.63
Performance unit awards with performance criteria
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing stock price (USD per share)	$ 9.80
Estimated payout for expense (as a percent)	100.00%
Fair value per performance share award (USD per share)	$ 9.80
Expense per performance share award (USD per share)	$ 9.80

Estimated Probability Of Criteria Being Earned Over Performance Period

No definition available.

Name:	lpi_EstimatedProbabilityOfCriteriaBeingEarnedOverPerformancePeriod
Namespace Prefix:	lpi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Grants In Period, Expense Per Performance Share Award

+ References

No definition available.

+ Details

Name:	lpi_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodExpensePerPerformanceShareAward
Namespace Prefix:	lpi_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
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

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

+ Details

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

- Definition

The risk-free interest rate assumption that is used in valuing an option on its own shares.

+ References

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
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

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

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

- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-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=120381028&loc=d3e5070-113901

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-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=115993241&loc=d3e301413-122809

+ Details

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

- Details

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

- Details

Name:	us-gaap_AwardDateAxis=lpi_March052020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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