Accumulated Other Comprehensive Income (Loss) (Reclassifications out of AOCI) (Details 3) - USD ($) $ in Thousands		3 Months Ended							9 Months Ended		12 Months Ended
		Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other (expense) income, net		$ 40,458	$ (11,678)	$ 1,105	$ (387,346)	$ 10,723	$ (268,114)	$ (133,273)	$ 29,885	$ (390,664)	$ (778,010)	$ 23,751
Income tax on unrealized gains on available-for-sale securities reclassified out of accumulated other comprehensive income									0	106,110
Amortization of net prior service cost (credit) included in net income		68				(101)			207	(305)
Amortization of net actuarial gain included in net income		(5,676)				(7,425)			(4,419)	(22,032)
Income Before Tax		261,435	(59,525)	589	(478,017)	(26,330)	(406,513)	(166,843)	202,499	(599,686)	(1,077,703)	(105,231)
(Benefit) Provision for Income Taxes		(30,500)	19,600	900	172,000	16,100	61,900	62,300	(10,000)	140,300	312,300	40,500
Interest expense		7,830	8,348	8,501	8,922	9,298	8,525	8,788	24,679	26,610	35,533	35,931
Curtailment gains		(51)				0			(51)	0
Income Net of Tax		230,935	$ (39,925)	$ 1,489	$ (306,017)	(10,230)	$ (344,613)	$ (104,543)	192,499	(459,386)	$ (765,403)	$ (64,731)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income Net of Tax		2,692				(4,385)			3,084	(172,179)
Foreign Currency Translation Adjustment [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other (expense) income, net		6,026				0			5,501	0
Unrealized Gain on Available-for-Sale Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other (expense) income, net		0				0			0	(265,274)
Income tax on unrealized gains on available-for-sale securities reclassified out of accumulated other comprehensive income	[1]	0				0			0	106,110
(Benefit) Provision for Income Taxes										1,200
Income Net of Tax		0				0			0	(159,164)
Unrealized Gain on Available-for-Sale Securities [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Berkshire Exchange Transaction [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income tax on unrealized gains on available-for-sale securities reclassified out of accumulated other comprehensive income										107,300
Pension and Other Postretirement Plans [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Amortization of net prior service cost (credit) included in net income	[2]	68				(101)			207	(305)
Amortization of net actuarial gain included in net income	[2]	(5,676)				(7,425)			(4,419)	(22,032)
Pension and Other Postretirement Plans [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income Before Tax		(5,557)				(7,526)			(4,161)	(22,337)
(Benefit) Provision for Income Taxes		2,223				3,011			1,665	8,935
Curtailment gains	[2]	51				0			51	0
Income Net of Tax		(3,334)				(4,515)			(2,496)	(13,402)
Cash Flow Hedge [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
(Benefit) Provision for Income Taxes		0				(87)			(53)	(258)
Interest expense		0				217			132	645
Income Net of Tax		$ 0				$ 130			$ 79	$ 387

[1] Benefits of $1.2 million were recorded in Provision for Income Taxes related to the realized loss for the nine months ended September 30, 2014. The remaining $107.3 million for the nine months ended September 30, 2014, relates to the reversal of income taxes previously recorded on the unrealized gain of the Company’s investment in Berkshire Hathaway Inc. marketable equity securities as part of the Berkshire exchange transaction (see Note 4).

[2] These accumulated other comprehensive income components are included in the computation of net periodic pension and postretirement plan cost (see Note 9).