Note 5 - Stock-Based Compensation (Detail) - Stock Options (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Balance, December 31, 2011	4,067,695			4,356,985	4,356,985
Balance, December 31, 2011 (in Dollars per share)	$ 29.40			$ 28.86	$ 28.86
Balance, December 31, 2011	2 years 255 days	3 years			3 years
Balance, December 31, 2011 (in Dollars)	$ 65			$ 37	$ 37
Balance - shares	4,067,414	4,067,695	4,067,414
Balance - weighted-average exercise price (in Dollars per share)	$ 29.40	$ 29.40	$ 29.40
Balance - weighted-average remaining contractual life	2 years 255 days	3 years			3 years
Balance - aggregate intrinisc value (in Dollars)	53	65	53
Exercisable, June 30, 2012	3,959,668		3,959,668
Exercisable, June 30, 2012 (in Dollars per share)	$ 29.57		$ 29.57
Exercisable, June 30, 2012	2 years 219 days
Exercisable, June 30, 2012 (in Dollars)	$ 53		$ 53
Exercised		(39,784)	(39,784)	(86,860)
Exercised (in Dollars per share)		$ 16.28
Forfeited - shares	(281)	(249,506)
Forfeited - weighted average exercise price (in Dollars per share)	$ 23.37	$ 22.27