(7) Shareholders' Equity (Details - Stock purchases) - Common Stock [Member] - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Class of Stock [Line Items]
Total stock purchases, shares	351,926	378,470
Total stock purchases, average price per share	$ 3.45	$ 3.97
Open Market Purchases [Member]
Class of Stock [Line Items]
Total stock purchases, shares	105,017	335,546
Total stock purchases, average price per share	$ 3.60	$ 3.95
Shares Redeemed [Member]
Class of Stock [Line Items]
Total stock purchases, shares	46,909	18,424
Total stock purchases, average price per share	$ 2.86	$ 3.76
Other Repurchases [Member]
Class of Stock [Line Items]
Total stock purchases, shares	200,000	24,500
Total stock purchases, average price per share	$ 3.51	$ 4.20