Name:	us-gaap_PropertyPlantAndEquipmentLineItems
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Data Type:	xbrli:stringItemType
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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.

No definition available.

Name:	us-gaap_PropertyPlantAndEquipmentUsefulLife
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
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Carrying amount of income producing properties held for rental.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.1(d))
-URI http://asc.fasb.org/extlink&oid=120400017&loc=d3e572229-122910

Name:	us-gaap_RentalProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

Amount of accumulated depreciation, depletion and amortization for rental properties.

No definition available.

Name:	zdpy_AccumulatedDepreciationDepletionAndAmortizationOfRentalProperties
Namespace Prefix:	zdpy_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Carrying amount of income producing properties held for rental properties.

No definition available.

Name:	zdpy_RentalPropertiesGross
Namespace Prefix:	zdpy_
Data Type:	xbrli:monetaryItemType
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Name:	srt_RangeAxis=srt_MinimumMember
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Name:	srt_RangeAxis=srt_MaximumMember
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