Income Taxes (Deferred Income Taxes Components) (Details 4) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Deferred Income Tax Liabilities [Line Items]
Employee benefit obligations	$ 69,013	$ 68,392
Accounts receivable	3,545	4,449
State income tax loss carryforwards	51,608	34,107
U.S. Federal income tax loss carryforwards	1,765	2,100
Non-U.S. income tax loss carryforwards	15,214	15,868
Leases	84,923	0
Other	6,003	14,657
Deferred tax assets	236,678	145,262
Valuation allowance	(46,243)	(33,120)
Deferred tax assets, net	190,435	112,142
Unrealized gain on available-for-sale securities	75,709	51,242
Goodwill and other intangible assets	92,233	88,798
Property, plant and equipment	16,303	9,997
Leases	74,407	0
Non-U.S. withholding tax	1,670	1,726
Deferred tax liabilities	606,178	421,175
Deferred Income Tax Liabilities, Net	415,743	309,033
non-U.S. [Member]
Deferred Income Tax Liabilities [Line Items]
Capital loss carryforwards	3,583	3,609
Non-U.S. income tax loss carryforwards	15,200
Valuation allowance	(11,400)
U.S. Federal [Member]
Deferred Income Tax Liabilities [Line Items]
U.S. Federal income tax loss carryforwards	1,800
U.S Federal foreign income tax credit carryforwards	717	987
State [Member]
Deferred Income Tax Liabilities [Line Items]
State income tax loss carryforwards	51,600
Capital loss carryforwards	307	1,093
Valuation allowance	(34,000)
Pension Plan [Member]
Deferred Income Tax Liabilities [Line Items]
Prepaid pension cost	$ 345,856	$ 269,412