Note 9 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Note 9 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	$ 166,184	$ 173,931
Unrealized Gains	37	26
Unrealized Losses	(474)	(383)
Total Fair Value	165,747	173,574
Fair Value of Investments in Unrealized Loss Position	47,250	52,740
Money Market Funds [Member]
Note 9 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	29,103	35,588
Unrealized Gains	0	0
Total Fair Value	29,103	35,588
US Government Agencies Short-term Debt Securities [Member]
Note 9 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	126,861	128,123
Unrealized Gains	37	26
Unrealized Losses	(49)	(23)
Total Fair Value	126,849	128,126
Fair Value of Investments in Unrealized Loss Position	37,455	42,880
Auction Rate Securities [Member]
Note 9 - Cash, Cash Equivalents and Investments (Details) - Unrealized Gains And Losses On Investments [Line Items]
Adjusted Cost	10,220	10,220
Unrealized Losses	(425)	(360)
Total Fair Value	9,795	9,860
Fair Value of Investments in Unrealized Loss Position	$ 9,795	$ 9,860