Accumulated Other Comprehensive Income (Loss) (Components of OCI) (Details 1) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before tax		$ 57,785	$ 12,244	$ 101,331	$ 536
Other Comprehensive Income (Loss), income tax		(18,540)	(5,039)	(26,665)	(866)
Other Comprehensive Income (Loss), Net of Tax		39,245	7,205	74,666	(330)
Foreign Currency Translation Adjustment [Member]
Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax		11,470	(353)	34,776	(1,629)
Other Comprehensive Income (Loss) before Reclassifications, Tax		0	0	0	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		11,470	(353)	34,776	(1,629)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				0
Other Comprehensive Income (Loss), Net of Tax				34,776
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax		47,836	12,154	71,370	7,190
Other Comprehensive Income (Loss) before Reclassifications, Tax		(19,134)	(4,862)	(28,548)	(2,876)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		28,702	7,292	42,822	4,314
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax				0	(6,256)
Reclassification from AOCI, Current Period, Tax				0	2,502
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				0	(3,754)
Other Comprehensive Income (Loss), before tax				71,370	934
Other Comprehensive Income (Loss), income tax				(28,548)	(374)
Other Comprehensive Income (Loss), Net of Tax				42,822	560
Pension and Other Postretirement Plans [Member]
Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				0
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax		(1,449)	394	(4,600)	1,182
Reclassification from AOCI, Current Period, Tax		580	(157)	1,840	(472)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		(869)	237	(2,760)	710
Other Comprehensive Income (Loss), before tax		(1,449)	394	(4,600)	1,182
Other Comprehensive Income (Loss), income tax		580	(157)	1,840	(472)
Other Comprehensive Income (Loss), Net of Tax		(869)	237	(2,760)	710
Net Prior Service Cost [Member]
Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	[1]	118	105	358	314
Reclassification from AOCI, Current Period, Tax		(47)	(41)	(143)	(125)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		71	64	215	189
Net Actuarial (Gain) Loss [Member]
Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	[1]	(1,567)	289	(4,958)	868
Reclassification from AOCI, Current Period, Tax		627	(116)	1,983	(347)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		(940)	173	(2,975)	521
Cash Flow Hedge [Member]
Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				(270)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				98
Other Comprehensive Income (Loss), before tax		(72)	49	(215)	49
Other Comprehensive Income (Loss), income tax		14	(20)	43	(20)
Other Comprehensive Income (Loss), Net of Tax		$ (58)	$ 29	$ (172)	$ 29

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