Note 8 - Investments in Marketable Securities (Details) - Amortized Cost and Estimated Fair Value of Debt Securities as Available for Sale (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Amortized Cost and Estimated Fair Value of Debt Securities as Available for Sale [Abstract]
Within 1 year	$ 11,789	$ 9,279
Within 1 year	11,849	9,324
1 to 5 years	86,787	91,787
1 to 5 years	87,807	92,011
6 to 10 years	47,045	40,387
6 to 10 years	46,724	38,335
Over 10 years	968	2,431
Over 10 years	838	2,333
	146,589	143,884
	$ 147,218	$ 142,003