Note 6 - Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2018

Notes Tables

Schedule of Net Benefit Costs [Table Text Block]

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2018			2017			2018			2017
Interest cost	$	1,106		$	1,528		$	2,212		$	2,335
Expected return on plan assets		(1,536	)		(1,848	)		(3,072	)		(2,824	)
Loss amortization		169			158			339			242
Net periodic income, net	$	(261	)	$	(162	)	$	(521	)	$	(247	)