Note 7 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Note 7 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	$ 174,180	$ 173,931
Unrealized Gains	31	26
Unrealized Losses	(387)	(383)
Total Fair Value	173,824	173,574
Fair Value of Investments in Unrealized Loss Position	49,455	52,740
Money Market Funds [Member]
Note 7 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	30,964	35,588
Unrealized Gains	0	0
Total Fair Value	30,964	35,588
US Government Agencies Short-term Debt Securities [Member]
Note 7 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	132,996	128,123
Unrealized Gains	31	26
Unrealized Losses	(15)	(23)
Total Fair Value	133,012	128,126
Fair Value of Investments in Unrealized Loss Position	39,607	42,880
Auction Rate Securities [Member]
Note 7 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	10,220	10,220
Unrealized Losses	(372)	(360)
Total Fair Value	9,848	9,860
Fair Value of Investments in Unrealized Loss Position	$ 9,848	$ 9,860