Note 1 - Summary of Significant Accounting Policies (Detail) - Stock Option Activity and Stock Options Outstanding (USD $) In Thousands, except Share data, unless otherwise specified	0 Months Ended	3 Months Ended
	Dec. 31, 2012	Mar. 31, 2013
Options outstanding/exercisable (Shares)	276,432
Options outstanding/exercisable (Exercise Price) (in Dollars per share)	$ 39.14
Options outstanding/exercisable (Remaining Contractual Life)	2 years 109 days	2 years 29 days
Exercised		(432)
Exercised (in Dollars per share)		$ 37.99
Options outstanding/exercisable (Shares)		276,000
Options outstanding/exercisable (Exercise Price) (in Dollars per share)		$ 39.14
Options outstanding/exercisable (Remaining Contractual Life)	2 years 109 days	2 years 29 days
Options outstanding/exercisable (Intrinsic Value of Unexercised In-The Money Options) (in Dollars)		$ 564