Note 2 - Stock-Based Compensation (Details) (USD $)	3 Months Ended				3 Months Ended			1 Months Ended			3 Months Ended		1 Months Ended	3 Months Ended		1 Months Ended		3 Months Ended
	Mar. 31, 2014		Mar. 31, 2013	Apr. 30, 2013 2014 Plan [Member]	Mar. 31, 2014 Time-Based RSU's and PSUs [Member]	Mar. 31, 2013 Time-Based RSU's and PSUs [Member]	Mar. 31, 2014 Time-Based RSUs, PSUs, MSUs [Member]	Feb. 28, 2014 2013 Time-Based RSUs and PSUs [Member] Executive Officer [Member]	Feb. 28, 2014 Time-Based RSUs [Member] Executive Officer [Member]	Feb. 28, 2014 Time-Based RSUs [Member] Non-Executive Employees [Member]	Mar. 31, 2014 Time-Based RSUs [Member]		Feb. 28, 2014 PSUs [Member] Executive Officer [Member]	Mar. 31, 2014 PSUs [Member]		Feb. 28, 2014 2012 Time-Based RSUs and PSUs [Member] Executive Officer [Member]	Mar. 31, 2014 2004 Plan [Member]	Mar. 31, 2014 Employee Stock Purchase Plan [Member]	Mar. 31, 2013 Employee Stock Purchase Plan [Member]
Note 2 - Stock-Based Compensation (Details) [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance (in Shares)																	2,900,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in Shares)				5,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested					$ 10,200,000	$ 8,700,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding							154,700,000
Share Price (in Dollars per share)	$ 38.77
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	400,000						61,200,000												200,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 year						6 years											5 months
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period (in Shares)	876,819	[1]						336,000			120,135	[1]		756,684	[1]
Percentage Of Time Based RSUs										25.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period									2 years				2 years
Percentage Of Time Based PSU													75.00%
Share Based Compensation Share Based Payment Other Than Options Percentage Allowed																300.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	6,900,000		5,600,000															0.5
Proceeds from Stock Options Exercised	5,600,000		9,800,000
Stock Issued During Period, Shares, Employee Stock Purchase Plans (in Shares)																		43,000	65,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in Shares)																		4,800,000
Proceeds from Stock Plans	$ 1,053,000		$ 1,167,000

[1] The number of PSUs granted reflects the maximum number of shares that can ultimately be earned assuming the achievement of the highest level of performance conditions under the programs.