Other Comprehensive Income (Loss) (Change In Accumulated Other Comprehensive Income By Component, Net Of Taxes And Noncontrolling Interest) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income, beginning balance	$ 1,354,508	$ 1,704,557
Other comprehensive income (loss) before reclassifications	390,462	(120,374)
Amounts reclassified from accumulated other comprehensive income	(22,693)	(13,105)
Total other comprehensive income (loss)	367,769	(133,479)
Accumulated other comprehensive income, ending balance	1,722,277	1,571,078
Unrealized Holding Gains On Available-For-Sale Securities [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income, beginning balance	1,472,762	1,793,254
Other comprehensive income (loss) before reclassifications	388,273	(109,001)
Amounts reclassified from accumulated other comprehensive income	(23,550)	(14,037)
Total other comprehensive income (loss)	364,723	(123,038)
Accumulated other comprehensive income, ending balance	1,837,485	1,670,216
Foreign Currency [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income, beginning balance	(72,696)	(43,491)
Other comprehensive income (loss) before reclassifications	2,189	(11,373)
Amounts reclassified from accumulated other comprehensive income	0	0
Total other comprehensive income (loss)	2,189	(11,373)
Accumulated other comprehensive income, ending balance	(70,507)	(54,864)
Net Actuarial Pension Loss [Member]
Accumulated Other Comprehensive Income [Line Items]
Accumulated other comprehensive income, beginning balance	(45,558)	(45,206)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income	857	932
Total other comprehensive income (loss)	857	932
Accumulated other comprehensive income, ending balance	$ (44,701)	$ (44,274)