Note 8 - Securities Available for Sale (Details) - Securities in a Continuous Unrealized Loss Position (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Other marketable securities:
Number of investments, less than twelve months	14	20
Fair value, less than twelve months	$ 66,690	$ 93,390
Unrealized losses, less than twelve months	(310)	(637)
Number of investments, twelve months and more	3	1
Fair value, twelve months and more	10,391	280
Unrealized losses, twelve months and more	(331)	(420)
Fair value	77,081	93,670
Unrealized losses	(641)	(1,057)
US Government Agencies Debt Securities [Member]
Other marketable securities:
Number of investments, less than twelve months	14	20
Fair value, less than twelve months	66,690	93,390
Unrealized losses, less than twelve months	(310)	(637)
Number of investments, twelve months and more	2	0
Fair value, twelve months and more	9,971	0
Unrealized losses, twelve months and more	(51)	0
Fair value	76,661	93,390
Unrealized losses	(361)	(637)
Corporate Debt Securities [Member]
Other marketable securities:
Number of investments, less than twelve months	0	0
Fair value, less than twelve months	0	0
Unrealized losses, less than twelve months	0	0
Number of investments, twelve months and more	1	1
Fair value, twelve months and more	420	280
Unrealized losses, twelve months and more	(280)	(420)
Fair value	420	280
Unrealized losses	$ (280)	$ (420)