Note 8 - Stock-Based Compensation (Detail) - Non-full value awards: (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013
Outstanding at December 31, 2012	770,355
Outstanding at December 31, 2012 (in Dollars per share)	$ 15.92
Outstanding at March 31, 2013	718,035
Outstanding at March 31, 2013 (in Dollars per share)	$ 16.16
Outstanding at March 31, 2013	2 years 292 days
Outstanding at March 31, 2013 (in Dollars)	$ 1,014	[1]
Exercisable shares at March 31, 2013	680,095
Exercisable shares at March 31, 2013 (in Dollars per share)	$ 16.34
Exercisable shares at March 31, 2013	2 years 255 days
Exercisable shares at March 31, 2013 (in Dollars)	824	[1]
Vested but unexercisable shares at March 31, 2013	14,560
Vested but unexercisable shares at March 31, 2013 (in Dollars per share)	$ 13.29
Vested but unexercisable shares at March 31, 2013	5 years 219 days
Vested but unexercisable shares at March 31, 2013 (in Dollars)	$ 69	[1]
Exercised	(52,320)
Exercised (in Dollars per share)	$ 12.62

[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.