Note 7 - Stock-Based Compensation (Details) - Stock Options - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options [Abstract]
Shares, outstanding	90	590	1,356	3,813
Weighted-average exercise price, outstanding	$ 17.50	$ 15.80	$ 15.86	$ 15.62
Weighted-average remaining contractual term, outstanding	1 year 109 days	1 year 73 days	1 year 328 days	2 years 219 days
Aggregate intrinsic value, outstanding	$ 4,134	$ 20,039	$ 25,506	$ 25,380
Shares	(498)	(742)	(2,446)
Weighted-average exercise price	$ 15.55	$ 16.09	$ 15.49
Shares	(2)	(24)	(11)
Weighted-average exercise price	$ 6.10	$ 10.07	$ 15.27
Options exercisable at December 31, 2015 and expected to vest	90
Options exercisable at December 31, 2015 and expected to vest	$ 17.50
Options exercisable at December 31, 2015 and expected to vest	1 year 109 days
Options exercisable at December 31, 2015 and expected to vest	$ 4,134
Options exercisable at December 31, 2015	89
Options exercisable at December 31, 2015	$ 17.50
Options exercisable at December 31, 2015	1 year 109 days
Options exercisable at December 31, 2015	$ 4,126