Accumulated Other Comprehensive Income (Loss) (Components of OCI) (Details 1) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before tax		$ 22,147	$ (14,536)	$ 43,546	$ (11,708)
Other Comprehensive Income (Loss), income tax		(5,008)	3,766	(8,125)	4,173
Other Comprehensive Income (Loss), Net of Tax		17,139	(10,770)	35,421	(7,535)
Foreign Currency Translation Adjustment [Member]
Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax		9,638	(5,121)	23,306	(1,276)
Other Comprehensive Income (Loss) before Reclassifications, Tax		0	0	0	0
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		9,638	(5,121)	23,306	(1,276)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				0
Other Comprehensive Income (Loss), Net of Tax				23,306
Unrealized Gains (Losses) on Available-for-Sale Securities [Member]
Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, before Tax		13,976	(5,307)	23,534	(4,964)
Other Comprehensive Income (Loss) before Reclassifications, Tax		(5,591)	2,123	(9,414)	1,986
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		8,385	(3,184)	14,120	(2,978)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax		0	(4,502)	0	(6,256)
Reclassification from AOCI, Current Period, Tax		0	1,801	0	2,502
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		0	(2,701)	0	(3,754)
Other Comprehensive Income (Loss), before tax		13,976	(9,809)	23,534	(11,220)
Other Comprehensive Income (Loss), income tax		(5,591)	3,924	(9,414)	4,488
Other Comprehensive Income (Loss), Net of Tax		8,385	(5,885)	14,120	(6,732)
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		(1,448)	394	(3,151)	788
Reclassification from AOCI, Current Period, Tax		579	(158)	1,260	(315)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		(869)	236	(1,891)	473
Other Comprehensive Income (Loss), before tax		(1,448)	394	(3,151)	788
Other Comprehensive Income (Loss), income tax		579	(158)	1,260	(315)
Other Comprehensive Income (Loss), Net of Tax		(869)	236	(1,891)	473
Net Prior Service Cost [Member]
Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	[1]	120	105	240	209
Reclassification from AOCI, Current Period, Tax		(48)	(43)	(96)	(84)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		72	62	144	125
Net Actuarial (Gain) Loss [Member]
Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	[1]	(1,568)	289	(3,391)	579
Reclassification from AOCI, Current Period, Tax		627	(115)	1,356	(231)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		(941)	174	(2,035)	348
Cash Flow Hedge [Member]
Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax				(172)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax				58
Other Comprehensive Income (Loss), before tax		(19)	0	(143)	0
Other Comprehensive Income (Loss), income tax		4	0	29	0
Other Comprehensive Income (Loss), Net of Tax		$ (15)	$ 0	$ (114)	$ 0

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