Note K - Accounting for Stock-Based Compensation (Details) - Outstanding Stock Option Activity (Employee Stock Option [Member], USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Employee Stock Option [Member]
Note K - Accounting for Stock-Based Compensation (Details) - Outstanding Stock Option Activity [Line Items]
Outstanding at January 1, 2011	638,800	460,653	392,369
Outstanding at January 1, 2011 (in Dollars per share)	$ 22.21	$ 20.50	$ 19.32
Shares, Exercised	(159,309)	(11,521)	(39,487)
Weighted Average Exercise Price, Exercised (in Dollars per share)	$ 19.48	$ 6.73	$ 12.11
Shares, Granted	218,707	203,436	190,552
Weighted Average Exercise Price, Granted (in Dollars per share)	$ 27.03	$ 25.39	$ 21.77
Shares, Forfeited/Expired	(3,646)	(13,768)	(82,781)
Weighted Average Exercise Price, Forfeited/Expired (in Dollars per share)	$ 24.84	$ 24.58	$ 21.85
Shares, Outstanding	694,552	638,800	460,653
Weighted Average Exercise Price, Outstanding (in Dollars per share)	$ 24.34	$ 22.21	$ 20.50
Aggregate Intrinsic Value, Outstanding (in Dollars)	$ 7,203
Vested plus expected to vest at December 31, 2013	678,431
Vested plus expected to vest at December 31, 2013 (in Dollars per share)	$ 24.29
Vested plus expected to vest at December 31, 2013 (in Dollars)	7,069
Exercisable at December 31, 2013	291,251
Exercisable at December 31, 2013 (in Dollars per share)	$ 22.35
Exercisable at December 31, 2013 (in Dollars)	$ 3,600