Employee and Retiree Benefit Plans (Plans' Benefit Obligations and Fair Value of Assets and Statement of Funded Status) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Change in plan assets
Fair value of plan assets, Ending Balance	$ 560,978,000	$ 533,108,000
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Liabilities associated with assets held for sale	(151,548,000)	(639,140,000)
Pension Benefits [Member]
Change in benefit obligation
Obligation at January 1	825,552,000	707,254,000	721,531,000
Service cost	22,470,000	26,346,000	23,500,000
Interest cost	33,680,000	30,903,000	29,869,000
Plan amendments		1,989,000
Participant contributions	5,000	21,000
Actuarial loss (gain)	122,824,000	(9,876,000)
Exchange rate changes	(14,614,000)	1,852,000
Benefits paid	(35,044,000)	(38,745,000)
Special termination benefits		849,000
Curtailments	(11,023,000)	(26,463,000)
Obligation assumed by MUSA at separation		(1,153,000)
Defined Benefit Plan, Benefit Obligation, Ending Balance	825,552,000	707,254,000	721,531,000
Change in plan assets
Fair value of plan assets, Beginning Balance	533,108,000	463,546,000
Actual return on plan assets	31,340,000	61,932,000
Employer contributions	47,279,000	46,726,000
Participant contributions	5,000	21,000
Exchange rate changes	(13,284,000)	1,594,000
Benefits paid	(35,044,000)	(38,745,000)
Other	(2,426,000)	(1,966,000)
Fair value of plan assets, Ending Balance	560,978,000	533,108,000	463,546,000
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Deferred charges and other assets	7,899,000	10,254,000
Other accrued liabilities	(5,996,000)	(5,565,000)
Deferred credits and other liabilities	(252,237,000)	(158,589,000)
Liabilities associated with assets held for sale	(14,240,000)	(20,246,000)
Funded status and net plan liability recognized at the end of the period	(264,574,000)	(174,146,000)
Other Postretirement Benefits [Member]
Change in benefit obligation
Obligation at January 1	118,496,000	107,001,000	124,134,000
Service cost	2,459,000	4,566,000	3,958,000
Interest cost	4,617,000	5,189,000	5,174,000
Participant contributions	1,406,000	1,376,000
Actuarial loss (gain)	8,150,000	(8,324,000)
Medicare Part D subsidy, Change in benefit obligation	404,000	384,000
Exchange rate changes	(55,000)	(36,000)
Benefits paid	(5,486,000)	(5,211,000)
Curtailments		(15,077,000)
Defined Benefit Plan, Benefit Obligation, Ending Balance	118,496,000	107,001,000	124,134,000
Change in plan assets
Employer contributions	3,676,000	3,451,000
Participant contributions	1,406,000	1,376,000
Medicare Part D subsidy, Fair value of plan assets	404,000	384,000
Benefits paid	(5,486,000)	(5,211,000)
Funded status and amounts recognized in the Consolidated Balance Sheets at December 31
Other accrued liabilities	(5,515,000)	(5,920,000)
Deferred credits and other liabilities	(112,981,000)	(101,081,000)
Funded status and net plan liability recognized at the end of the period	$ (118,496,000)	$ (107,001,000)