Rental Properties (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Rental Properties (Textual)
Depreciation and amortization of rental properties	$ 89,297	$ 88,820	$ 178,338	$ 177,640

The current period expense charged against earnings on long-lived, physical assets not used in production, and which are not intended for resale, to allocate or recognize the cost of such assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset; or to reflect consumption during the period of an asset that is not used in production.

No definition available.

Name:	zdpy_DepreciationAndAmortizationOfRentalProperties
Namespace Prefix:	zdpy_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration