Accumulated Other Comprehensive Income (Loss) (Reclassifications out of AOCI) (Details 3) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other (expense) income, net		$ 28,513	$ 18,225	$ (19,000)	$ (15,096)	$ (21,262)	$ 40,458	$ (11,678)	$ 1,105	$ 12,642		$ 8,623		$ (778,010)
Income from discontinued operations, net of tax						0	(379)	(18,502)	(23,289)	0		(42,170)		(527,857)
Interest expense		10,857	8,614	7,971	7,948	7,975	7,830	8,348	8,501	35,390		32,654		35,533
Provision for Income Taxes		27,200	7,800	23,800	22,400	30,500	(30,500)	19,600	900	81,200		20,500		312,300
Income from continuing operations before income taxes		$ (64,118)	$ (40,926)	$ (84,999)	$ (60,615)	(81,609)	261,435	(59,525)	589	(250,658)		120,890		(1,077,703)
Income Net of Tax						$ (51,109)	$ 230,935	$ (39,925)	$ 1,489	(169,458)		141,390		(765,403)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Income Net of Tax										(8,710)		(171)		(176,951)
Foreign Currency Translation Adjustments [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax												5,501		(404)
Provision for income taxes												0		0
Reclassifications, net of tax										0		5,501		(404)
Foreign Currency Translation Adjustments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other (expense) income, net	[1]									0		5,501
Income from discontinued operations, net of tax	[1]													(404)
Unrealized Gains (Losses) on Available- for- Sale Securities [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax										1,879		(4)		(265,274)
Provision for income taxes										(752)		2		106,110
Reclassifications, net of tax										1,127		(2)		(159,164)
Unrealized Gains (Losses) 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										1,879		(4)		(265,274)
Provision for Income Taxes										(752)	[2]	2	[2]	1,200
Income tax on unrealized gains on available-for-sale securities reclassified out of accumulated other comprehensive income	[2]													106,110
Income Net of Tax										1,127		(2)		(159,164)
Unrealized Gains (Losses) 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]
Reclassifications, before tax										(16,417)		(9,580)		(29,819)
Provision for income taxes										6,567		3,831		11,928
Reclassifications, net of tax										(9,850)		(5,749)		(17,891)
Net Actuarial Loss [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax	[3]									1,157		(9,906)		(29,412)
Provision for income taxes										(463)		3,962		11,765
Reclassifications, net of tax										694		(5,944)		(17,647)
Net Prior Service Cost [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax	[3]									419		275		(407)
Provision for income taxes										(167)		(110)		163
Reclassifications, net of tax										252		165		(244)
Curtailment Gains Included in Net Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax	[3]									(17,993)		51		0
Provision for income taxes										7,197		(21)
Reclassifications, net of tax										(10,796)		30
Cash Flow Hedge [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax										13		79
Cash Flow Hedge [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense										16		132		847
Provision for Income Taxes										(3)		(53)		(339)
Income Net of Tax										$ 13		$ 79		$ 508

[1] The amount for 2015 was recorded in other (expense) income, net and the amount for 2014 was recorded in income from discontinued operations, net of tax.

[2] The amounts for 2016 and 2015 were recorded in Provision for Income Taxes. Benefits of $1.2 million were recorded in Provision for Income Taxes related to the realized loss for the year ended December 31, 2014. The remaining $107.3 million for the year relates to the reversal of income taxes previously recorded on the unrealized gain of the Company’s investment in Berkshire Hathaway Inc. marketable securities as part of the Berkshire exchange transaction, which qualified as a tax-free distribution under IRC Section 355 and 361 (see Note 7).

[3] These accumulated other comprehensive income components are included in the computation of net periodic pension and postretirement plan cost (see Note 14).