Accumulated Other Comprehensive Income (Loss) (Reclassifications out of AOCI) (Details 3) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net		$ (1,963)	$ 18,225	$ (6,881)	$ (15,871)
Interest expense		8,619	8,614	25,783	24,533
Provision for Income Taxes		13,400	7,800	40,000	54,000
Net of Tax		(24,844)	(33,126)	(87,929)	(132,540)
Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Net of Tax		(829)	235	(2,662)	(3,046)
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, before tax				0	(6,256)
Provision for Income Tax				0	2,502
Reclassifications, net of tax				0	(3,754)
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 income (expense), net		0	0	0	(6,256)
Provision for Income Taxes		0	0	0	2,502
Net of Tax		0	0	0	(3,754)
Pension and Other Postretirement Plans [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax		(1,449)	394	(4,600)	1,182
Provision for Income Tax		580	(157)	1,840	(472)
Reclassifications, net of tax		(869)	237	(2,760)	710
Net Prior Service Cost [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax	[1]	118	105	358	314
Provision for Income Tax		(47)	(41)	(143)	(125)
Reclassifications, net of tax		71	64	215	189
Net Actuarial (Gain) Loss [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, before tax	[1]	(1,567)	289	(4,958)	868
Provision for Income Tax		627	(116)	1,983	(347)
Reclassifications, net of tax		(940)	173	(2,975)	521
Cash Flow Hedge [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Reclassifications, net of tax				98
Cash Flow Hedge [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Interest expense		51	(3)	123	(3)
Provision for Income Taxes		(11)	1	(25)	1
Net of Tax		$ 40	$ (2)	$ 98	$ (2)

[1] These accumulated other comprehensive income components are included in the computation of net periodic pension and postretirement plan cost (see Note 8).