Note 4 - Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2022

Table Text Block [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

	Three Months Ended September 30,						Nine Months Ended September 30,
	2022			2021			2022			2021
Service cost	$	1,566		$	1,455		$	4,697		$	4,365
Interest cost		1,369			1,248			4,107			3,744
Expected return on plan assets		(3,363	)		(2,313	)		(10,089	)		(6,939	)
Amortization of prior service cost		128			99			384			297
Amortization of net loss		512			1,125			1,537			3,375
Net periodic pension cost	$	212		$	1,614		$	636		$	4,842