Note 18 - Retirement Plans - Plan Assets and Funded Status of the Domestic Pension Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, beginning of period	$ 46,650
Fair value of plan assets, end of period	40,541	$ 46,650
Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, beginning of period	46,650	39,524
Actual return on plan assets	(2,879)	6,663
Contributions	360	3,885
Benefits paid	(3,590)	(3,422)
Fair value of plan assets, end of period	40,541	46,650
Unfunded status	(12,880)	(12,536)
Accrued benefit cost, end of period	$ (12,880)	$ (12,536)