Note 11 - Stock-Based Compensation (Detail) - Summary of Outstanding Stock Options by Exercise Prices (USD $)	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Dec. 31, 2010
Options Outstanding (in Shares)	1,340,678	1,482,077	472,327
Weighted Average Exercise Price	3 years 73 days
Weighted Average Remaining Contractual Life	$ 46.47	$ 46.92	$ 43.07
$37.70 [Member] | Minimum [Member]
Exercise Prices	$ 37.70
$37.70 [Member]
Options Outstanding (in Shares)	58,407
Weighted Average Exercise Price	1 year 292 days
Weighted Average Remaining Contractual Life	$ 37.70
$42.99-$46.69 [Member] | Minimum [Member]
Exercise Prices	$ 42.99
$42.99-$46.69 [Member] | Maximum [Member]
Exercise Prices	$ 46.69
$42.99-$46.69 [Member]
Options Outstanding (in Shares)	1,192,271
Weighted Average Exercise Price	3 years 255 days
Weighted Average Remaining Contractual Life	$ 46.53
$51.50-$52.50 [Member] | Minimum [Member]
Exercise Prices	$ 51.50
$51.50-$52.50 [Member]
Options Outstanding (in Shares)	90,000
Weighted Average Exercise Price	292 days
Weighted Average Remaining Contractual Life	$ 51.50