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, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits [Member]
Change in benefit obligation
Obligation at January 1	$ 815,593	$ 794,589	$ 825,552	$ 815,593	$ 794,589
Service cost	8,136	17,948	22,470
Interest cost	25,185	33,168	33,680
Plan amendments		8,297
Participant contributions		4
Actuarial loss (gain)	58,236	(48,019)
Exchange rate changes	(30,447)	(15,337)
Benefits paid	(40,928)	(35,936)
Special termination benefits		8,606
Curtailments	822	306
Obligation at December 31	815,593	794,589	825,552
Change in plan assets
Fair value of plan assets at January 1	521,682	560,978
Actual return on plan assets	61,860	(18,718)
Employer contributions	8,186	31,442
Participant contributions		4
Exchange rate changes	(30,609)	(14,104)
Benefits paid	(40,928)	(35,936)
Other				(834)	(1,984)
Fair value of plan assets at December 31	519,357	521,682	560,978
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Deferred charges and other assets				7,591	7,463
Other accrued liabilities				(8,184)	(7,487)
Deferred credits and other liabilities				(295,643)	(272,883)
Funded status and net plan liability recognized at December 31				(296,236)	(272,907)
Other Postretirement Benefits [Member]
Change in benefit obligation
Obligation at January 1	106,679	115,222	118,496	106,679	115,222
Service cost	1,864	3,180	2,459
Interest cost	3,800	4,883	4,617
Participant contributions	1,278	1,276
Actuarial loss (gain)	(10,627)	(7,436)
Medicare Part D subsidy	510	510
Exchange rate changes	20	(112)
Benefits paid	(5,369)	(5,575)
Curtailments	(19)
Obligation at December 31	106,679	115,222	$ 118,496
Change in plan assets
Employer contributions	3,581	3,789
Participant contributions	1,278	1,276
Medicare Part D subsidy	510	510
Benefits paid	$ (5,369)	$ (5,575)
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Other accrued liabilities				(5,267)	(5,370)
Deferred credits and other liabilities				(101,412)	(109,852)
Funded status and net plan liability recognized at December 31				$ (106,679)	$ (115,222)