Note 8 - Employee Benefit Plans - Amounts Recognized in the Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current liabilities:
Accrued benefit liability	$ (471)	$ (420)
Non- current pension liability:
Accrued benefit liability	(46,628)	(44,491)
Accumulated other comprehensive loss	42,243	40,917
Net amount recognized	$ (4,856)	$ (3,994)