Impact of Recently Issued Accounting Standards Impact of recently issued accounting standards table (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended							6 Months Ended				12 Months Ended
		Jun. 30, 2018		Dec. 31, 2017	Sep. 30, 2017	Jul. 01, 2017		Apr. 01, 2017	Jun. 30, 2018		Jul. 01, 2017		Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sales		$ 7,392,528	[1]	$ 7,539,449	$ 6,856,108	$ 6,422,226	[1]	$ 5,736,780	$ 14,268,141	[1]	$ 12,159,006	[1]	$ 26,554,563
Cost of sales		6,459,708		6,610,269	6,013,541	5,598,202		4,975,583	12,466,377		10,573,785		23,197,595
Gross Profit		932,820				824,024			1,801,764		1,585,221
Selling, general, and administrative expenses		580,388				531,781			1,143,357		1,047,307
Depreciation and amortization		46,422				37,381			93,669		74,522
Restructuring, integration, and other charges		19,183				24,416			40,354		39,921
Costs and Expenses		645,993				593,578			1,278,942		1,161,750
Operating income		286,827		286,824	235,441	230,446		193,025	522,822		423,471		945,736
Equity in earnings (losses) of affiliated companies		517				724			(156)		1,649
Gain (loss) on investments, net		(2,563)				2,263			(5,015)		4,245
Loss on extinguishment of debt		0				58,759			0		58,759		58,759
Post-retirement expense		1,257				1,897			2,488		3,697
Interest and other financing expense, net		60,803				42,538			105,982		80,787
Income before income taxes		222,721				130,239			409,181		286,122
Provision for income taxes		51,681				29,592			98,271		69,156
Consolidated net income		171,040				100,647			310,910		216,966
Noncontrolling interests		1,125				925			1,901		2,507
Net income attributable to shareholders		$ 169,915		53,653	134,064	$ 99,722		114,737	$ 309,009		$ 214,459		402,176
Basic		$ 1.94				$ 1.12			$ 3.52		$ 2.41
Diluted	[2]	$ 1.92				$ 1.11			$ 3.48		$ 2.38
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement													16,706
Accounting standards update 2018-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification to retained earnings									$ 4,116
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sales				7,633,870	6,953,740	$ 6,465,346		5,759,552			$ 12,224,898		26,812,508
Cost of sales				6,703,742	6,110,382	5,641,380		4,999,665			10,641,045		23,455,169
Gross Profit						823,966					1,583,853
Selling, general, and administrative expenses						532,347					1,047,866
Depreciation and amortization						37,381					74,522
Restructuring, integration, and other charges						24,416					39,921
Costs and Expenses						594,144					1,162,309
Operating income				270,914	235,992	229,822		191,722			421,544		928,450
Equity in earnings (losses) of affiliated companies						724					1,649
Gain (loss) on investments, net						750					750
Loss on extinguishment of debt						58,759					58,759
Post-retirement expense						0					0
Interest and other financing expense, net						42,358					80,431
Income before income taxes						130,179					284,753
Provision for income taxes						29,575					68,799
Consolidated net income						100,604					215,954
Noncontrolling interests						925					2,507
Net income attributable to shareholders				$ 53,885	$ 134,630	$ 99,679		$ 113,768			$ 213,447		$ 401,962
Basic						$ 1.12					$ 2.40
Diluted	[2]					$ 1.11					$ 2.37
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Sales						$ (43,120)					$ (65,892)
Cost of sales						(43,178)					(67,260)
Gross Profit						58					1,368
Selling, general, and administrative expenses						(566)					(559)
Depreciation and amortization						0					0
Restructuring, integration, and other charges						0					0
Costs and Expenses						(566)					(559)
Operating income						624					1,927
Equity in earnings (losses) of affiliated companies						0					0
Gain (loss) on investments, net						1,513					3,495
Loss on extinguishment of debt						0					0
Post-retirement expense						1,897					3,697
Interest and other financing expense, net						180					356
Income before income taxes						60					1,369
Provision for income taxes						17					357
Consolidated net income						43					1,012
Noncontrolling interests						0					0
Net income attributable to shareholders						$ 43					$ 1,012
Basic						$ 0.00					$ 0.01
Diluted	[2]					$ 0.00					$ 0.01
Accounting Standards Update 2016-01 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification to retained earnings									$ 18,238

[1] Includes sales related to the United States of $2,968,469 and $5,618,137 for the second quarter and first six months of 2018 and $2,667,958 and $5,010,086 for the second quarter and first six months of 2017, respectively.

[2] Stock-based compensation awards for the issuance of 915 and 515 shares for the second quarter and first six months of 2018 and 432 and 328 shares for the second quarter and first six months of 2017, respectively, were excluded from the computation of net income per share on a diluted basis as their effect was anti-dilutive.