Insurance (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statutory Accounting Practices [Line Items]
Assets Held by Insurance Regulators	$ 13	$ 14
Insurance Expenses [Abstract]
Insurance losses	75	77	43
Loss adjustment expenses	4	6	4
Reinsurance Income and Other Expenses, Net	(9)	(3)	(1)
Insurance expenses	70	80	46
Liability for reported insurance claims and estimate of unreported claims	6	14
Ceded insurance expenses	64	74	87
Premiums Written and Earned [Abstract]
Direct premiums written	234	219	167
Assumed premiums written	2	8	4
Ceded premiums written	(136)	(137)	(89)
Net premiums written	100	90	82
Direct premiums earned	202	205	229
Assumed premiums earned	2	8	5
Ceded premiums earned	(99)	(113)	(136)
Net premiums earned	$ 105	$ 100	$ 98