XML 58 R43.htm IDEA: XBRL DOCUMENT
v3.21.2

Summary of Significant Accounting Policies - Schedule of Property, Plant and Equipment, Useful Life (Details) | 12 Months Ended
--- | ---
Apr. 30, 2021
Computer Equipment & Software [Member] |
Property and equipment, useful life (Year) | 3 years
Equipment Under Capitalized Lease [Member] |
Property and equipment, useful life | Over the life of the lease
Leasehold Improvements [Member] |
Property and equipment, useful life | Shorter of the estimated useful life or lease term
Minimum [Member] |
Property and equipment, useful life (Year) | 3 years
Minimum [Member] | Equipment [Member] |
Property and equipment, useful life (Year) | 5 years
Minimum [Member] | Office Furniture & Fixtures [Member] |
Property and equipment, useful life (Year) | 3 years
Maximum [Member] |
Property and equipment, useful life (Year) | 7 years
Maximum [Member] | Equipment [Member] |
Property and equipment, useful life (Year) | 7 years
Maximum [Member] | Office Furniture & Fixtures [Member] |
Property and equipment, useful life (Year) | 7 years

X
- Definition Describes the periods of time over which an entity anticipates to receive utility from its property, plant and equipment (that is, the periods of time over which an entity allocates the initial cost of its property, plant and equipment). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 35 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=123364984&loc=d3e1205-110223 + Details
Name: | us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=OPTT_ComputerEquipmentAndSoftwareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=OPTT_EquipmentUnderCapitalizedLeaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_LeaseholdImprovementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_EquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=OPTT_OfficeFurnitureAndFixturesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |