Accumulated Other Comprehensive Income (Loss) (Reclassifications out of AOCI) (Details 3) - USD ($) $ in Thousands		3 Months Ended						9 Months Ended
		Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		$ 9,343			$ 7,247			$ 25,144	$ 22,302
(Benefit from) Provision for Income Taxes		(5,900)			30,000			78,500	26,500
Net of Tax		(39,683)	$ (115,926)	$ (112,635)	(78,054)	$ (18,862)	$ 33,891	(268,244)	(63,025)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net of Tax		(74)			878			(1,058)	2,461
Foreign Currency Translation Adjustment [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax								0
Pension and Other Postretirement Plans [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax		(273)			975			(2,042)	2,924
Provision for (Benefit from) Income Tax		50			(263)			528	(789)
Reclassifications, net of tax		(223)			712			(1,514)	2,135
Net Prior Service (Credit) Cost [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax	[1]	793			671			2,377	2,010
Provision for (Benefit from) Income Tax		(188)			(180)			(615)	(542)
Reclassifications, net of tax		605			491			1,762	1,468
Net Actuarial Gain [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax	[1]	(1,066)			304			(4,419)	914
Provision for (Benefit from) Income Tax		238			(83)			1,143	(247)
Reclassifications, net of tax		(828)			221			(3,276)	667
Cash Flow Hedges [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax								456
Cash Flow Hedges [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		149			166			456	313
(Benefit from) Provision for Income Taxes		0			0			0	13
Net of Tax		$ 149			$ 166			$ 456	$ 326

[1] These accumulated other comprehensive income components are included in the computation of net periodic pension and postretirement plan cost (see Note 12) and are included in non-operating pension and postretirement benefit income in the Company’s Condensed Consolidated Statements of Operations.