Note 4 - Retirement Plans (Details) - Components of net periodic benefit cost for our pension plans (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Components of net periodic benefit cost for our pension plans [Abstract]
Service cost	$ 1,325	$ 1,147	$ 2,649	$ 2,295
Interest cost	917	830	1,834	1,660
Expected return on plan assets	(830)	(682)	(1,659)	(1,365)
Loss amortization	742	576	1,484	1,151
Net periodic benefit cost	$ 2,154	$ 1,871	$ 4,308	$ 3,741