Insurance Premiums and Service Revenue Earned (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Premiums Written and Earned [Abstract]
Direct Premiums Written, Property and Casualty	$ 337	$ 359	$ 359
Direct Premiums Earned, Property and Casualty	339	326	337
Assumed Premiums Written, Property and Casualty	44	38	210
Assumed Premiums Earned, Property and Casualty	49	76	281
Gross Insurance Premiums Written	381	397	569
Gross Insurance Premiums Earned	388	402	618
Ceded Premiums Written, Property and Casualty	(141)	(129)	(229)
Ceded Premiums Earned, Property and Casualty	(109)	(126)	(228)
Premiums Written, Net, Property and Casualty	240	268	340
Premiums Earned, Net, Property and Casualty	279	276	390
Insurance Commissions and Fees Written	826	788	718
Insurance Commissions and Fees	780	894	981
Insurance Services Revenue Written	1,066	1,056	1,058
Insurance premiums and service revenue earned	$ 1,059	$ 1,170	$ 1,371