Accumulated Other Comprehensive Income (Loss) (Reclassifications out of AOCI) (Details 3) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		$ 6,135	$ 8,619	$ 31,371	$ 25,783
Provision for Income Taxes		10,000	13,400	39,700	40,000
Net of Tax		(125,070)	(24,844)	(214,670)	(87,929)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net of Tax		(2,401)	(829)	(5,733)	(2,662)
Foreign Currency Translation Adjustment [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax				0
Unrealized Gain on Available-for-Sale Securities [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		(3,226)	(1,449)	(7,741)	(4,600)
Provision for Income Tax		873	580	2,090	1,840
Reclassifications, net of tax		(2,353)	(869)	(5,651)	(2,760)
Net Prior Service Cost [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax	[1]	69	118	215	358
Provision for Income Tax		(18)	(47)	(58)	(143)
Reclassifications, net of tax		51	71	157	215
Net Actuarial (Gain) Loss [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax	[1]	(3,295)	(1,567)	(7,956)	(4,958)
Provision for Income Tax		891	627	2,148	1,983
Reclassifications, net of tax		(2,404)	(940)	(5,808)	(2,975)
Cash Flow Hedge [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax				(82)
Cash Flow Hedge [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		(59)	51	(101)	123
Provision for Income Taxes		11	(11)	19	(25)
Net of Tax		$ (48)	$ 40	$ (82)	$ 98

[1] These accumulated other comprehensive income components are components 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.