Note 10 - Employee Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2021

Notes Tables

Schedule of Net Benefit Costs [Table Text Block]

	Pension benefits												Postretirement benefits
	Three months ended						Six months ended						Three months ended						Six months ended
	June 30,						June 30,						June 30,						June 30,
	2021			2020			2021			2020			2021			2020			2021			2020
Service cost	$	32		$	29		$	64		$	58		$	3		$	3		$	5		$	5
Interest cost		21			31			43			62			4			5			8			10
Expected return on plan assets		(54	)		(49	)		(108	)		(98	)
Amortization of prior service cost (credit)		1			2			2			3			(2	)		(2	)		(3	)		(3	)
Recognition of actuarial loss (gain)		10			(2	)		10			(2	)		1						1
Total pension and postretirement benefit expense	$	10		$	11		$	11		$	23		$	6		$	6		$	11		$	12