Note 16 - Benefit Plans - Accumulated Benefit Obligation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accumulated benefit obligation at end of period	$ 0	$ 65,978
Projected benefit obligation at beginning of period	65,978	72,631
Interest cost	2,401	2,575	$ 2,688
Net actuarial (gain) loss	3,452	(6,820)
Benefits paid	(31,321)	(2,408)
Annuities purchased	(40,510)	0
Projected benefit obligation at end of period	0	65,978	72,631
Balance at beginning of period	61,870	58,014
Actual return on plan assets	8,944	(3,507)
Company contributions	1,017	9,771
Benefits paid	(31,321)	(2,408)
Annuities purchased	(40,510)	0
Balance at end of period	0	61,870	$ 58,014
Funded status: accrued pension liability included in other long-term liabilities	0	(4,108)
Net actuarial loss, net of tax	$ 0	$ (10,541)