Note 18 - Retirement Plans - Changes in the Fair Value of the Domestic Plan's Level 3 Assets (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
Fair value of plan assets, end of period	40,541	46,650
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, beginning of period	2,214
Fair value of plan assets, end of period	2,236	2,214
Fair Value, Inputs, Level 3 [Member] | Pension Plan [Member] | UNITED STATES
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets, beginning of period	2,214
Actual return on plan assets	22
Fair value of plan assets, end of period	$ 2,236	$ 2,214