Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	$ 173,574	$ 113,235
Fair Value, Inputs, Level 1 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	35,588	15,959
Fair Value, Inputs, Level 2 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	128,126	85,521
Fair Value, Inputs, Level 3 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	9,860	11,755
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	35,588	15,959
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	0	0
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	0	0
Money Market Funds [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	35,588	15,959
US Government Agencies Short-term Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	0	0
US Government Agencies Short-term Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	128,126	85,521
US Government Agencies Short-term Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	0	0
US Government Agencies Short-term Debt Securities [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	128,126	85,521
Auction Rate Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	9,860	11,755
Auction Rate Securities [Member]
Note 2 - Cash, Cash Equivalents and Investments (Details) - Fair Value Heirarchy [Line Items]
Available For Sale Securities	$ 9,860	$ 11,755