Consolidated Statements of Comprehensive Income (Parentheticals) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plans
Change in pension plans and post employment expense (benefits), tax expense (benefit)	$ 0	$ 0	$ 160
Post-employment benefits
Change in pension plans and post employment expense (benefits), tax expense (benefit)	$ 40	$ 90	$ (41)