XML 81 R49.htm IDEA: XBRL DOCUMENT
v3.23.1

Note 8 - Commitments and Contingencies (Details Textual) - USD ($) | 1 Months Ended | 12 Months Ended
--- | --- | ---
Jun. 30, 2018 | Dec. 31, 2022 | Dec. 31, 2021
Payments for Reimbursement of Filtration and Maintenance |  | $ 21,000 | $ 59,000
Notice and Finding of Violation and Order [Member] |  |  |
Loss Contingency, Damages Sought, Value | $ 230,000 |  |

X
- Definition Cash payments made for reimbursement of filtration and maintenance. + References No definition available. + Details
Name: | mlp_PaymentsForReimbursementOfFiltrationAndMaintenance
Namespace Prefix: | mlp_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The value (monetary amount) of the award the plaintiff seeks in the legal matter. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 9 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349 + Details
Name: | us-gaap_LossContingencyDamagesSoughtValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | srt_LitigationCaseAxis=mlp_NoticeAndFindingOfViolationAndOrderMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |