Note C - Marketable Equity Securities (Details) - Recognized Gains (Losses) in Market Value for Securities - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Trading securities
Recognized gain (loss)	$ 133	$ 52	$ 146	$ 8
Net recognized (loss) gain for the period	(50)	5	(63)	49
Net recognized (loss) gain for the period, net of taxes	(31)	3	(39)	29
Recognized gain (loss)	$ 83	$ 57	$ 83	$ 57

Amount of gain (loss) realized from securities classified as trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.7(c))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

Name:	us-gaap_TradingSecuritiesRealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration