Note 5 - Stock-Based Compensation (Detail) - Stock Options (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Balance, December 31, 2011	4,067,414	4,067,695				4,356,985	4,356,985
Balance, December 31, 2011 (in Dollars per share)	$ 29.40	$ 29.40				$ 28.86	$ 28.86
Balance, December 31, 2011	2 years 6 months	2 years 255 days	3 years				3 years
Balance, December 31, 2011 (in Dollars)	$ 53	$ 65				$ 37	$ 37
Balance - shares	4,033,810	4,067,414	4,067,695		4,033,810
Balance - weighted-average exercise price (in Dollars per share)	$ 29.41	$ 29.40	$ 29.40		$ 29.41
Balance - weighted-average remaining contractual life	2 years 6 months	2 years 255 days	3 years				3 years
Balance - aggregate intrinisc value (in Dollars)	61	53	65		61
Exercisable, September 30, 2012	3,926,694				3,926,694
Exercisable, September 30, 2012 (in Dollars per share)	$ 29.57				$ 29.57
Exercisable, September 30, 2012	2 years 146 days
Exercisable, September 30, 2012 (in Dollars)	$ 61				$ 61
Exercised	0		(39,784)	0	(39,784)	(86,860)
Exercised (in Dollars per share)			$ 16.28
Forfeited - shares	(33,604)	(281)	(249,506)
Forfeited - weighted average exercise price (in Dollars per share)	$ 28.92	$ 23.37	$ 22.27