Accumulated Other Comprehensive Income (Summary Of Accumulated Other Comprehensive Income, Net Of Taxes) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, net	$ 438,793	$ 447,082	$ 538,050
Net Unrealized Gains (Losses) On Available For Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, net	557,601	577,588	589,393
Net Unrealized Foreign Exchange Gains (Losses) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, net	(63,248)	(26,771)	16,803
Net Unrealized Losses On Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, net	0	0	(169)
Accumulated Defined Benefit Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive income, net	$ (55,560)	$ (103,735)	$ (67,977)