Note 11 - Stock-Based Compensation (Detail) - Summary of Outstanding Stock Options (USD $) In Thousands, except Share data, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Dec. 31, 2010
Options outstanding	1,340,678	1,482,077	472,327
Options outstanding (in Dollars per share)	$ 46.47	$ 46.92	$ 43.07
Options outstanding (in Dollars)	$ 502,000
Options exercisable at June 30, 2012	238,407
Options exercisable at June 30, 2012 (in Dollars per share)	$ 45.78
Options exercisable at June 30, 2012 (in Dollars)	$ 459,000
Options granted	64,271	1,264,719
Options granted (in Dollars per share)	$ 44.26	$ 46.58
Options exercised	(120,050)	(224,969)
Options exercised (in Dollars per share)	$ 46.46	$ 37.30
Options cancelled or expired	(85,620)	(30,000)
Options cancelled or expired (in Dollars per share)	$ 52.50	$ 44.25