Note 7 - Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2017

Notes Tables

Schedule of Net Benefit Costs [Table Text Block]

	Three Months Ended September 30,
	2017			2016
Service cost	$	1,196		$	1,077
Interest cost		1,339			1,307
Expected return on plan assets		(1,462	)		(1,325	)
Amortization of prior service cost		(84	)		(84	)
Amortization of net loss		1,033			1,093
Net periodic pension cost	$	2,022		$	2,068

	Nine Months Ended September 30,
	2017			2016
Service cost	$	3,588		$	3,231
Interest cost		4,017			3,921
Expected return on plan assets		(4,386	)		(3,975	)
Amortization of prior service cost		(252	)		(252	)
Amortization of net loss		3,099			3,279
Net periodic pension cost	$	6,066		$	6,204