Income taxes - Schedule of refund of AMT carryforward (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Income Tax Disclosure [Abstract]
2020	$ 1,031
2021	516
2022	515
AMT credit carryforward	$ 2,062

Deferred Tax Asset, Alternative Minimum Tax Carryforward Refund Receivable, In Year 2

No definition available.

Name:	lpi_DeferredTaxAssetAlternativeMinimumTaxCarryforwardRefundReceivableInYear2
Namespace Prefix:	lpi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant