Leases - Lease Income (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lessor, Lease, Description [Line Items]
Total real estate revenue from operating leases	$ 49,425	$ 48,350	$ 146,225	$ 130,132
Daney Ranch
Lessor, Lease, Description [Line Items]
Total real estate revenue from operating leases	16,000	3,300	21,000	6,600
Gold Hill Hotel
Lessor, Lease, Description [Line Items]
Total real estate revenue from operating leases	13,500	24,000	61,500	72,000
Lab and office space
Lessor, Lease, Description [Line Items]
Total real estate revenue from operating leases	5,000	7,500	20,000	15,000
Land
Lessor, Lease, Description [Line Items]
Total real estate revenue from operating leases	4,500	4,500	13,500	13,500
All other residential
Lessor, Lease, Description [Line Items]
Total real estate revenue from operating leases	$ 10,425	$ 9,050	$ 30,225	$ 23,032