Equity and Noncontrolling Interest - Reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	$ (72,938)	$ (71,790)	$ (87,407)	$ (73,316)
Other Comprehensive Income (Loss) Before Reclassifications	5,994	(314)	19,004	43
Amounts Reclassified from AOCI	530	433	3,395	2,449
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	6,524	119	22,399	2,492
Related Tax Amounts	(259)	(356)	(1,665)	(1,203)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	6,265	(237)	20,734	1,289
Accumulated Other Comprehensive Loss, Balance at End of Period	(66,673)	(72,027)	(66,673)	(72,027)
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	(40,062)	(38,812)	(52,255)	(38,544)
Other Comprehensive Income (Loss) Before Reclassifications	5,917	(892)	18,110	(1,160)
Amounts Reclassified from AOCI	0	0	0	0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	5,917	(892)	18,110	(1,160)
Related Tax Amounts	0	0	0	0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	5,917	(892)	18,110	(1,160)
Accumulated Other Comprehensive Loss, Balance at End of Period	(34,145)	(39,704)	(34,145)	(39,704)
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	(34,059)	(34,070)	(36,168)	(35,251)
Other Comprehensive Income (Loss) Before Reclassifications	(611)	3	(684)	116
Amounts Reclassified from AOCI	784	713	4,284	2,313
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	173	716	3,600	2,429
Related Tax Amounts	(111)	(256)	(1,429)	(788)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	62	460	2,171	1,641
Accumulated Other Comprehensive Loss, Balance at End of Period	(33,997)	(33,610)	(33,997)	(33,610)
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated Other Comprehensive Loss, Balance at Beginning of Period	1,183	1,092	1,016	479
Other Comprehensive Income (Loss) Before Reclassifications	688	575	1,578	1,087
Amounts Reclassified from AOCI	(254)	(280)	(889)	136
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	434	295	689	1,223
Related Tax Amounts	(148)	(100)	(236)	(415)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	286	195	453	808
Accumulated Other Comprehensive Loss, Balance at End of Period	$ 1,469	$ 1,287	$ 1,469	$ 1,287