Note 8 - Shareholders' Equity (Details) - Information about stock options granted (USD $) In Thousands, except Per Share data, unless otherwise specified			12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 $40 - $45 [Member]	Dec. 31, 2013 $45 - $50 [Member]	Dec. 31, 2013 $50 - $55 [Member]	Dec. 31, 2013 $55 - $60 [Member]	Dec. 31, 2013 $40 - $60 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise Price Range, Lower Limit			$ 40	$ 45	$ 50	$ 55	$ 40
Options Outstanding, Number Outstanding (in Shares)	2,078	2,328	355	616	880	227	2,078
Options Outstanding, Aggregate Intrinsic Value (in Dollars)			$ 4,557	$ 5,375	$ 4,232		$ 14,164
Options Outstanding, Weighted Average Remaining Contractual Life (yrs)			8 years 219 days	4 years	3 years 292 days	6 years	4 years 328 days
Options Outstanding, Weighted Average Exercise Price			$ 44	$ 48	$ 52	$ 57	$ 50
Options Exercisable, Number Outstanding (in Shares)			44	443	801	227	1,515
Options Exercisable, Aggregate Intrinsic Value (in Dollars)			$ 591	$ 3,564	$ 3,786		$ 7,941
Exercise Price Range, Upper Limit			$ 45	$ 50	$ 55	$ 60	$ 60
Options Exercisable, Weighted Average Remaining Contractual Life (yrs)			5 years 36 days	2 years 146 days	3 years 6 months	6 years	3 years 219 days
Options Exercisable, Weighted Average Exercise Price			$ 43	$ 48	$ 52	$ 57	$ 51