Note 6 - Capital Stock (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended		6 Months Ended
	Jul. 23, 2015	Apr. 23, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Oct. 27, 2011
Note 6 - Capital Stock (Details) [Line Items]
Stock Repurchase Program, Authorized Amount							$ 500.0
Stock Repurchase Program, Remaining Authorized Repurchase Amount			$ 179.0		$ 179.0
Treasury Stock, Shares, Acquired (in Shares)			331,000		410,000
Treasury Stock, Value, Acquired			$ 28.0		$ 34.4
Common Stock, Dividends, Per Share, Declared (in Dollars per share)		$ 0.21	$ 0.21	$ 0.20	$ 0.42	$ 0.40
Subsequent Event [Member]
Note 6 - Capital Stock (Details) [Line Items]
Common Stock, Dividends, Per Share, Declared (in Dollars per share)	$ 0.21