Note 2 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Note 2 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	$ 173,931	$ 113,687
Unrealized Gains	26	45
Unrealized Losses	(383)	(497)
Total Fair Value	173,574	113,235
Fair Value of Investments in Unrealized Loss Position	52,740	25,876
Money Market Funds [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	35,588	15,959
Unrealized Gains	0	0
Total Fair Value	35,588	15,959
US Government Agencies Short-term Debt Securities [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	128,123	85,483
Unrealized Gains	26	45
Unrealized Losses	(23)	(7)
Total Fair Value	128,126	85,521
Fair Value of Investments in Unrealized Loss Position	42,880	14,121
Auction Rate Securities [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	10,220	12,245
Unrealized Losses	(360)	(490)
Total Fair Value	9,860	11,755
Fair Value of Investments in Unrealized Loss Position	$ 9,860	$ 11,755