Concentrations and Risks (Details)	Jun. 30, 2020 USD ($)
Future annual base rent:
2020 (remainder of year)	$ 456,917
2021	1,082,005
2022	1,074,000
2023	1,074,000
2024	1,074,000
Thereafter	16,468,000
Total	$ 21,238,922

Future minimum rental payments in aggregate as of the balance sheet date under operating leases.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121578510&loc=d3e41551-112718

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future rental payments receivable within one year of the balance sheet date under an operating lease.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future rental payments receivable within the fifth year from the balance sheet date under an operating lease.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future rental payments receivable within the fourth year from the balance sheet date under an operating lease.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future rental payments receivable within the third year from the balance sheet date under an operating lease.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future rental payments receivable within the second year from the balance sheet date under an operating lease.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Future minimum lease payments receivable under operating leases for periods greater than five years following the balance sheet date.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

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Namespace Prefix:	zdpy_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration