Employee and Retiree Benefit Plans (Plans' Benefit Obligations and Fair Value of Assets and Statement of Funded Status) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017
Change in plan assets
Total beginning balance	$ 563,825
Total ending balance	487,094	$ 563,825
Pension Benefits [Member]
Change in benefit obligation
Obligation at January 1	777,645	881,932	$ 815,593	$ 777,645	$ 881,932
Service cost	8,994	8,279	8,136
Interest cost	26,168	27,047	25,185
Participant contributions
Actuarial loss (gain)	(57,378)	60,855
Medicare Part D subsidy
Exchange rate changes	(12,742)	18,751
Benefits paid	(41,132)	(39,910)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax	737
Other	(28,934)	(8,683)
Obligation at December 31	777,645	881,932	815,593
Change in plan assets
Total beginning balance	563,825	519,357
Actual return on plan assets	(18,951)	50,079
Employer contributions	24,357	24,918
Participant contributions
Medicare Part D subsidy
Exchange rate changes	12,071	(18,064)
Benefits paid	(41,132)	(39,910)
Other				(28,934)	(8,683)
Total ending balance	487,094	563,825	519,357
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Deferred charges and other assets				11,039	5,905
Other accrued liabilities				(9,175)	(8,856)
Deferred credits and other liabilities				(292,415)	(315,156)
Funded status and net plan liability recognized at December 31				(290,551)	(318,107)
Other Postretirement Benefits [Member]
Change in benefit obligation
Obligation at January 1	94,779	106,276	106,679	94,779	106,276
Service cost	1,965	1,601	1,864
Interest cost	3,427	3,444	3,800
Participant contributions	2,104	2,075
Actuarial loss (gain)	(13,778)	(3,077)
Medicare Part D subsidy	325	318
Exchange rate changes	(67)	46
Benefits paid	(5,473)	(4,810)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax
Other
Obligation at December 31	94,779	106,276	106,679
Change in plan assets
Total beginning balance
Actual return on plan assets
Employer contributions	3,044	2,417
Participant contributions	2,104	2,075
Medicare Part D subsidy	325	318
Exchange rate changes
Benefits paid	(5,473)	(4,810)
Other
Total ending balance
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Deferred charges and other assets
Other accrued liabilities				(5,101)	(5,392)
Deferred credits and other liabilities				(89,678)	(100,884)
Funded status and net plan liability recognized at December 31				$ (94,779)	$ (106,276)