Note 7 - Marketable Securities (Details) - Balance of Held-to-Maturity Debt Securities by Contractual Maturity (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Balance of Held-to-Maturity Debt Securities by Contractual Maturity [Abstract]
Due in one year or less	$ 25,255
Due after one year through five years	57,325
Total marketable securities	$ 82,580	$ 100,362