Note 14 - Benefit Plans - Accumulated Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated benefit obligation at end of period	$ 65,978	$ 72,631
Projected benefit obligation at beginning of period	72,631	65,956
Interest cost	2,575	2,688	$ 2,747
Net actuarial (gain) loss	(6,820)	6,170
Benefits paid	(2,408)	(2,183)
Projected benefit obligation at end of period	65,978	72,631	65,956
Balance at beginning of period	58,014	46,488
Actual return on plan assets	(3,507)	8,382
Company contributions	9,771	5,327
Benefits paid	(2,408)	(2,183)
Balance at end of period	61,870	58,014	$ 46,488
Funded status: accrued pension liability included in other long-term liabilities	(4,108)	(14,617)
Net actuarial loss, net of tax	$ (10,571)	$ (10,978)