Note C - Marketable Equity Securities (Details Textual) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Available-for-sale Securities [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 6,216,000		$ 6,216,000		$ 5,310,000
Trading Securities	0		0		0
Trading Securities, Accumulated Gross Recognized Loss		$ 0		$ 0
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities	176,000	579,000	709,000	579,000
Marketable Securities, Reclassification			0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0		0		0
Accumulated Other Comprehensive Income (Loss), Net of Tax	6,216,000		6,216,000		5,310,000
Available-for-Sale Securities Net Unrealized Holding Gain (Loss), Net of Tax			906,000		1,079,000
Trading Securities, Accumulated Gross Recognized Gain		59,000		59,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,941,000		1,941,000		5,099,000
Available-for-sale Equity Securities, Gross Unrealized Loss			96,000		1,333,000
Investment Income, Dividend	279,000	$ 288,000	781,000	$ 788,000
Trading Securities Pledged as Collateral	$ 10,597,000		$ 10,597,000		$ 11,949,000