TAXABLE INCOME AND TAX BASIS (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
TAXABLE INCOME AND TAX BASIS
Excess amount of statement income over taxable income					$ 57,000
Excess amount of cumulative statement basis over cumulative taxable basis					7,200,000
Excess amount of statement income from joint venture investments over taxable income					2,100,000
Reconciliation of GAAP net income to taxable income
Financial statement ("book") net income	$ 2,483,707	$ 980,586	$ 4,377,941	$ 2,211,351
Reconciliation of Income from Book Basis to Tax Basis Profit (Loss) Tax Basis					$ 4,893,000