INVESTMENTS (Details) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Available-for-sale securities
Aggregate par value	$ 1,600,000	$ 1,700,000
Amortized cost	943,000
Total	1,415,000	1,349,000
Realized gains from investments in available-for-sale securities	4,000
Amortized cost
Due within one year	94,000
Due after five years through ten years	849,000
Total	943,000
Estimated fair value
Due within one year	142,000
Due after five years through ten years	1,273,000
Total	1,415,000	1,349,000
U.S. Treasury Bonds
Available-for-sale securities
Amortized cost	943,000	894,000
Gross unrealized gains	472,000	455,000
Total	1,415,000	1,349,000
Amortized cost
Total	943,000	894,000
Estimated fair value
Total	1,415,000	1,349,000
U.S. Treasury Bonds, maturing 2020
Available-for-sale securities
Aggregate par value	1,600,000
U.S. Treasury Bonds, maturing 2022
Available-for-sale securities
Aggregate par value	$ 1,700,000