4. Land Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Inventory Disclosure [Abstract]
Fully improved land	$ 14	$ 14

Amount before accumulated deprecation and depletion of additions or improvements to real estate held for productive use. Examples include, but are not limited to, walkways, driveways, fences, and parking lots.

No definition available.

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