Other - Other Income - Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Other Income and Expenses [Abstract]
Dividend and royalty income	$ (1,521)	$ (1,198)	$ (2,972)	$ (3,042)
Net expense from banking activities	2,450	2,513	4,686	4,985
Foreign currency transaction related losses (gains)	5,626	976	3,164	(2,610)
Miscellaneous pension income	(3,903)	(10,726)	(7,447)	(11,793)
Other income	(6,999)	(5,937)	(14,108)	(10,897)
Other expense	3,208	1,876	6,266	5,427
Total	$ (1,139)	$ (12,496)	$ (10,411)	$ (17,930)