Note 8 - Stock-Based Compensation (Details) - Non-full value awards: (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended
	Jun. 30, 2013
Non-full value awards: [Abstract]
Outstanding at December 31, 2012	770,355
Outstanding at December 31, 2012 (in Dollars per share)	$ 15.92
Outstanding at June 30, 2013	618,820
Outstanding at June 30, 2013 (in Dollars per share)	$ 16.61
Outstanding at June 30, 2013	2 years 328 days
Outstanding at June 30, 2013 (in Dollars)	$ 560	[1]
Exercisable shares at June 30, 2013	596,520
Exercisable shares at June 30, 2013 (in Dollars per share)	$ 16.92
Exercisable shares at June 30, 2013	2 years 292 days
Exercisable shares at June 30, 2013 (in Dollars)	381	[1]
Vested but unexercisable shares at June 30, 2013	8,100
Vested but unexercisable shares at June 30, 2013 (in Dollars per share)	$ 8.44
Vested but unexercisable shares at June 30, 2013	5 years 219 days
Vested but unexercisable shares at June 30, 2013 (in Dollars)	$ 65	[1]
Exercised	(151,355)
Exercised (in Dollars per share)	$ 13.11
Forfeited	(180)
Forfeited (in Dollars per share)	$ 12.08

[1] The intrinsic value of a stock option is the difference between the market value of the underlying stock and the exercise price of the option.