Note 10 - Summary of Deferred Compensation Plan (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Other Long-term Assets [Member]
Deferred compensation plan assets reported in:
Other long-term assets	$ 16,217	$ 13,985
Accrued Compensation and Related Benefits [Member]
Deferred compensation plan liabilities reported in:
Deferred compensation plan liabilities	952
Other Long-term Liabilities [Member]
Deferred compensation plan liabilities reported in:
Deferred compensation plan liabilities	15,395	14,147
Other long-term assets	16,217	13,985
Deferred compensation plan liabilities	$ 16,347	$ 14,147