Comprehensive Income (Loss) (Components Of Comprehensive Income (Loss) In The Consolidated Statements Of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Comprehensive Income (Loss) [Line Items]
Before Tax	$ 35,364	$ (1,532)
Tax Effect	(7,478)	516
Net of Tax	27,886	(1,016)
Reclassification, Before Tax	1,165	1,457
Reclassification, Tax Effect	(245)	(306)
Reclassification, Net of Tax	920	1,151
Total, Before Tax	(224,773)	124,144
Total, Tax Effect	46,422	(25,996)
Total, Net of Tax	(178,351)	98,148
URA(D) On Securities [Member]
Comprehensive Income (Loss) [Line Items]
Before Tax	(223,770)	112,441
Tax Effect	46,246	(23,730)
Net of Tax	(177,524)	88,711
Total, Net of Tax	(149,638)	87,695
URA(D) On Securities - OTTI [Member]
Comprehensive Income (Loss) [Line Items]
Before Tax		(332)
Tax Effect		(70)
Net of Tax		(262)
Total, Net of Tax		(262)
Foreign Currency Translation Adjustments [Member]
Comprehensive Income (Loss) [Line Items]
Before Tax	(37,532)	12,110
Tax Effect	7,899	(2,546)
Net of Tax	(29,633)	9,564
Total, Net of Tax	(29,633)	9,564
Benefit Plan Net Gain (Loss) [Member]
Comprehensive Income (Loss) [Line Items]
Total, Net of Tax	$ 920	$ 1,151