Note 8 - Accrued Retirement Benefits - Accrued Retirement Benefits (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Pension Plan [Member]
Accrued retirement benefits	$ 1,997	$ 2,540
Supplemental Employee Retirement Plan [Member]
Accrued retirement benefits	4,587	4,468
Deferred Compensation Plan [Member]
Accrued retirement benefits	229	276
Accrued retirement benefits	6,813	7,284
Less current portion	(343)	(391)
Non-current portion of accrued retirement benefits	$ 6,470	$ 6,893