Income Taxes (Schedule of Effective Income Tax Rate Reconciliation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Statutory federal income tax rate	35.00%
Income Tax Expense (Benefit), Continuing Operations, Income Tax Reconciliation [Abstract]
Computed “expected” tax expense	$ 244,611	$ 245,675	$ 179,580
Tax-exempt investment income	(40,679)	(50,665)	(57,246)
Change in valuation allowance	0	0	(2,328)
Impact of lower foreign tax rates	(4,851)	(5,234)	(3,199)
State and local taxes	2,906	(753)	2,355
Other, net	(8,400)	2,262	2,783
Total expense	$ 193,587	$ 191,285	$ 121,945