Note 8 - Stock-Based Compensation (Details) - Stock options exercised: (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Stock options exercised: [Abstract]
Proceeds from stock options exercised	$ 212	$ 570	$ 235	$ 814
Fair value of shares received upon exercised of stock options	937		1,574	548
Tax benefit related to stock options exercised	115	3	168	27
Intrinsic value of stock options exercised	$ 203	$ 16	$ 377	$ 130