Equity and Noncontrolling Interest - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	$ (58,738)	$ (81,961)	$ (65,100)	$ (87,407)
Other Comprehensive Income (Loss) Before Reclassifications	(16,674)	7,758	(11,050)	13,010
Amounts Reclassified from AOCI	1,460	2,375	2,071	2,865
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(15,214)	10,133	(8,979)	15,875
Related Tax Amounts	(399)	(1,110)	(272)	(1,406)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(15,613)	9,023	(9,251)	14,469
Accumulated Other Comprehensive Loss, Balance at End of Period	(74,351)	(72,938)	(74,351)	(72,938)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	(25,129)	(47,327)	(31,893)	(52,255)
Other Comprehensive Income (Loss) Before Reclassifications	(16,940)	7,265	(10,176)	12,193
Amounts Reclassified from AOCI	0	0	0	0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(16,940)	7,265	(10,176)	12,193
Related Tax Amounts	0	0	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(16,940)	7,265	(10,176)	12,193
Accumulated Other Comprehensive Loss, Balance at End of Period	(42,069)	(40,062)	(42,069)	(40,062)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	(34,009)	(35,850)	(34,093)	(36,168)
Other Comprehensive Income (Loss) Before Reclassifications	1,161	268	464	(73)
Amounts Reclassified from AOCI	779	2,650	1,562	3,500
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	1,940	2,918	2,026	3,427
Related Tax Amounts	(444)	(1,127)	(446)	(1,318)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	1,496	1,791	1,580	2,109
Accumulated Other Comprehensive Loss, Balance at End of Period	(32,513)	(34,059)	(32,513)	(34,059)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	400	1,216	886	1,016
Other Comprehensive Income (Loss) Before Reclassifications	(895)	225	(1,338)	890
Amounts Reclassified from AOCI	681	(275)	509	(635)
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(214)	(50)	(829)	255
Related Tax Amounts	45	17	174	(88)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(169)	(33)	(655)	167
Accumulated Other Comprehensive Loss, Balance at End of Period	$ 231	$ 1,183	$ 231	$ 1,183