Note 10 - Deferred Compensation Plan - Summary of Deferred Compensation Plan (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Other Long-term Assets [Member]
Deferred compensation plan assets reported in:
Other long-term assets	$ 17,396	$ 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	16,422	14,147
Other long-term assets	17,396	13,985
Deferred compensation plan liabilities	$ 17,374	$ 14,147