Note 5 - Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2015

Compensation and Retirement Disclosure [Abstract]

Schedule of Net Benefit Costs [Table Text Block]

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2015			2014			2015			2014
Service cost	$	1,405		$	1,300		$	3,116		$	2,644
Interest cost		3,194			1,034			4,448			2,103
Expected return on plan assets		(3,710	)		(1,057	)		(5,114	)		(2,151	)
Loss amortization		900			244			1,740			496
Net periodic cost	$	1,789		$	1,521		$	4,190		$	3,092