Note 4 - Share-Based Compensation (Detail) - Stock option activity (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Outstanding at December 31, 2011	769,401
Outstanding at December 31, 2011 (in Dollars per share)	$ 25.73
Granted	79,630	166,008
Granted (in Dollars per share)	$ 45.28
Exercised	(164,000)
Exercised (in Dollars per share)	$ 19.93
Cancelled	(131,012)
Cancelled (in Dollars per share)	$ 27.47
Outstanding at September 30, 2012	554,019
Outstanding at September 30, 2012 (in Dollars per share)	$ 29.84
Outstanding at September 30, 2012	6 years 215 days
Outstanding at September 30, 2012 (in Dollars)	$ 11,317
Exercisable at September 30, 2012	306,524
Exercisable at September 30, 2012 (in Dollars per share)	$ 25.26
Exercisable at September 30, 2012	5 years 160 days
Exercisable at September 30, 2012 (in Dollars)	$ 7,666