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, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits [Member]
Change in benefit obligation
Obligation at January 1	$ 794,589	$ 825,552	$ 707,254	$ 794,589	$ 825,552
Service cost	17,948	22,470	26,346
Interest cost	33,168	33,680	30,903
Plan amendments	8,297
Participant contributions	4	5
Actuarial loss (gain)	(48,019)	122,824
Exchange rate changes	(15,337)	(14,614)
Benefits paid	(35,936)	(35,044)
Special termination benefits	8,606
Curtailments	306	(11,023)
Obligation at December 31	794,589	825,552	707,254
Change in plan assets
Fair value of plan assets at January 1	560,978	533,108
Actual return on plan assets	(18,718)	31,340
Employer contributions	31,442	47,279
Participant contributions	4	5
Exchange rate changes	(14,104)	(13,284)
Benefits paid	(35,936)	(35,044)
Other				(1,984)	(2,426)
Fair value of plan assets at December 31	521,682	560,978	533,108
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Deferred charges and other assets				7,463	7,899
Other accrued liabilities				(7,487)	(5,996)
Deferred credits and other liabilities				(272,883)	(266,477)
Funded status and net plan liability recognized at December 31				(272,907)	(264,574)
Other Postretirement Benefits [Member]
Change in benefit obligation
Obligation at January 1	115,222	118,496	107,001	115,222	118,496
Service cost	3,180	2,459	4,566
Interest cost	4,883	4,617	5,189
Participant contributions	1,276	1,406
Actuarial loss (gain)	(7,436)	8,150
Medicare Part D subsidy	510	404
Exchange rate changes	(112)	(55)
Benefits paid	(5,575)	(5,486)
Obligation at December 31	115,222	118,496	$ 107,001
Change in plan assets
Employer contributions	3,789	3,676
Participant contributions	1,276	1,406
Medicare Part D subsidy	510	404
Benefits paid	$ (5,575)	$ (5,486)
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Other accrued liabilities				(5,370)	(5,515)
Deferred credits and other liabilities				(109,852)	(112,981)
Funded status and net plan liability recognized at December 31				$ (115,222)	$ (118,496)