XML 39 R27.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Commitments and Contingencies (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2021
Commitments And Contingencies Disclosure [Abstract] |
Summary of Lease Liabilities and Right-of-Use Assets | The table below summarizes the Company’s lease liabilities and corresponding right-of-use assets (in thousands, except years and rates):
|  | 2021 |  |  | 2020 |
Assets |  |  |  |  |  |
Operating | $ | 341 |  | $ | 636 |
Financing |  | — |  |  | 7 |
Total leased assets | $ | 341 |  | $ | 643 |
Liabilities |  |  |  |  |  |
Current: |  |  |  |  |  |
Operating | $ | 111 |  | $ | 123 |
Financing | — |  | 10 |
Noncurrent: |  |  |  |  |  |
Operating | 269 |  | 528 |
Total lease liabilities | $ | 380 |  | $ | 661 |
Weighted-average remaining lease term (years) - operating leases | 2.86 |  | 6.57 |
Weighted-average remaining lease term (years) - finance leases | — |  | 0.42 |
Weighted-average discount rate - operating leases |  | 9.00 | % |  | 7.79 | %
Weighted-average discount rate - finance leases |  | N/A |  |  | 5.00 | %
Summary of Lease Costs | The table below summarizes the Company’s lease costs from its consolidated statements of operations, and cash payments from its consolidated statements of cash flows.
|  | Year Ended December 31, |
|  |  | 2021 |  |  | 2020 |
Lease expense: |  |  |  |  |  |  |
Operating lease expense |  | $ | 211 |  | $ | 210 |
Finance lease expense: |  |  |  |  |  |  |
Depreciation of right-of-use assets |  |  | 7 |  | 127 |
Interest expense on lease liabilities |  | — |  | 4 |
Total lease expense |  | $ | 218 |  | $ | 341 |
Cash payment information: |  |  |  |  |  |  |
Operating cash used for operating leases |  | $ | 206 |  | $ | 204 |
Financing cash used for financing leases |  | 8 |  | 117 |
Total cash paid for amounts included in the measurement of lease liabilities |  | $ | 214 |  | $ | 321 |
Summary of Future Minimum Annual Lease Payments under Operating and Financing Leases | The Company’s future minimum annual lease payments under operating and financing leases at December 31, 2021 are as follows (in thousands):
|  | Operating Leases |  |
2022 | $ | 159 |  |
2023 |  | 137 |  |
2024 |  | 113 |  |
2025 |  | 18 |  |
Thereafter |  |  | — |
Total minimum lease payments | $ |  | 427 |
Less: amount representing interest |  |  | (47 | )
Present value of obligations under leases |  |  | 380 |
Less: current portion |  |  | (111 | )
Noncurrent lease obligations | $ |  | 269 |

X
- Definition Schedule of operating and financing lease liability maturity. + References No definition available. + Details
Name: | pstv_ScheduleOfOperatingAndFinancingLeaseLiabilityMaturityTableTextBlock
Namespace Prefix: | pstv_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Schedule of right of use assets and lease liabilities. + References No definition available. + Details
Name: | pstv_ScheduleOfRightOfUseAssetsAndLeaseLiabilitiesTableTextBlock
Namespace Prefix: | pstv_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_CommitmentsAndContingenciesDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of lessee's lease cost. Includes, but is not limited to, interest expense for finance lease, amortization of right-of-use asset for finance lease, operating lease cost, short-term lease cost, variable lease cost and sublease income. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 20 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=123408670&loc=SL77918686-209980 + Details
Name: | us-gaap_LeaseCostTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration