Equity and Noncontrolling Interest - AOCI Reclassifications (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	$ (87,407)	$ (73,316)	$ (54,406)
Other Comprehensive (Loss) Income, before Reclassifications, before Tax	21,015	(17,106)	(20,025)
Amounts Reclassed from AOCI	2,660	3,058	3,010
Related Tax Amounts	(1,368)	(43)	(1,895)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(65,100)	(87,407)	(73,316)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(52,255)	(38,544)	(14,312)
Other Comprehensive (Loss) Income, before Reclassifications, before Tax	20,362	(13,711)	(24,232)
Amounts Reclassed from AOCI	0	0	0
Related Tax Amounts	0	0	0
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(31,893)	(52,255)	(38,544)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	(36,168)	(35,251)	(41,551)
Other Comprehensive (Loss) Income, before Reclassifications, before Tax	(1,646)	(4,229)	5,057
Amounts Reclassed from AOCI	5,154	3,075	3,642
Related Tax Amounts	(1,433)	237	(2,399)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	(34,093)	(36,168)	(35,251)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	1,016	479	1,457
Other Comprehensive (Loss) Income, before Reclassifications, before Tax	2,299	834	(850)
Amounts Reclassed from AOCI	(2,494)	(17)	(632)
Related Tax Amounts	65	(280)	504
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	$ 886	$ 1,016	$ 479