Reinsurance (Incurred Consolidated Property Casualty Insurance Loss And Loss Expenses On Assumed And Ceded Business) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Net incurred loss and loss expenses	$ 2,505	$ 2,322	$ 2,524
Property, Liability and Casualty Insurance Product Line [Member]
Direct incurred loss and loss expenses	2,323	2,235	2,588
Assumed incurred loss and loss expenses	11	6	24
Ceded incurred loss and loss expenses	(33)	(104)	(277)
Net incurred loss and loss expenses	$ 2,301	$ 2,137	$ 2,335