Note 4 - Marketable Securities and Time Deposits (Details) - Marketable Debt Securities by Contractual Maturities - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Note 4 - Marketable Securities and Time Deposits (Details) - Marketable Debt Securities by Contractual Maturities [Line Items]
Marketable debt securities, amortized cost	$ 103,972	$ 104,072
Marketable debt securities, estimated fair value	103,964	$ 103,777
Debt Securities [Member]
Note 4 - Marketable Securities and Time Deposits (Details) - Marketable Debt Securities by Contractual Maturities [Line Items]
Marketable debt securities, amortized cost	103,972
Marketable debt securities, unrealized gains	176
Marketable debt securities, unrealized losses	(184)
Marketable debt securities, estimated fair value	103,964
Debt Securities [Member] \| Due in One Year or Less [Member]
Note 4 - Marketable Securities and Time Deposits (Details) - Marketable Debt Securities by Contractual Maturities [Line Items]
Marketable debt securities, amortized cost	17,677
Marketable debt securities, unrealized gains	27
Marketable debt securities, unrealized losses	(2)
Marketable debt securities, estimated fair value	17,702
Debt Securities [Member] \| Due After One Year to Five Years [Member]
Note 4 - Marketable Securities and Time Deposits (Details) - Marketable Debt Securities by Contractual Maturities [Line Items]
Marketable debt securities, amortized cost	86,295
Marketable debt securities, unrealized gains	149
Marketable debt securities, unrealized losses	(182)
Marketable debt securities, estimated fair value	$ 86,262

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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