Income Tax (Total Income Taxes Provided) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Effects Allocated Directly to Equity [Abstract]
Income Tax Expense (Benefit)	$ 242,629	$ 324,486	$ 216,417
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	(339,889)	348,697	(467,454)
Income Tax Effects Allocated Directly to Equity, Employee Stock Options	(2,963)	3,011	(3,125)
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax	16,478	22,998	12,330
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax	1,726	(14,770)	7,640
Income Tax Expense (Benefit), Intraperiod Tax Allocation	$ (82,019)	$ 684,422	$ (234,192)