Note 7 - Employee Benefit Plans (Tables)

6 Months Ended

Jun. 30, 2015

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

	Three Months Ended June 30,
	2015			2014
Service cost	$	1,054		$	1,020
Interest cost		1,206			1,186
Expected return on plan assets		(1,345	)		(1,249	)
Amortization of prior service cost		(84	)		(84	)
Amortization of net (gain) loss		1,065			756
Net periodic pension cost	$	1,896		$	1,629

	Six Months Ended June 30,
	2015			2014
Service cost	$	2,108		$	2,040
Interest cost		2,412			2,372
Expected return on plan assets		(2,691	)		(2,498	)
Amortization of prior service cost		(169	)		(168	)
Amortization of net (gain) loss		2,130			1,512
Net periodic pension cost	$	3,790		$	3,258