Note 12 - Stock-Based Compensation (Detail) - Summary of Outstanding Stock Options (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Number of Shares	1,134,602	1,482,077
Weighted Average Exercise Price (in Dollars per share)	$ 46.75	$ 46.92
Aggregate Intrinsic Value (in Dollars)	$ 265,000
Options exercisable at March 31, 2013	197,602
Options exercisable at March 31, 2013 (in Dollars per share)	$ 47.03
Options exercisable at March 31, 2013 (in Dollars)	$ 265,000
Number of Shares	21,640	63,516
Weighted Average Exercise Price (in Dollars per share)	$ 49.50	$ 44.24
Options exercised		(295,371)
Options exercised (in Dollars per share)		$ 45.41
Options cancelled		(115,620)
Options cancelled (in Dollars per share)		$ 50.99
Number of Shares	1,156,242	1,134,602
Weighted Average Exercise Price (in Dollars per share)	$ 46.80	$ 46.75