Income Taxes (Details) (USD $) In Millions, unless otherwise specified	6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Deferred Tax Assets Liabilities Net
Net deferred tax liability	$ 251	$ 283
Percent of total permanent tax differences related to investment revenues	99.00%
Indemnity
Deferred Tax Assets Liabilities Net
Net deferred tax liability	1	26
Effective Tax Rate when investment permanent tax differences are considered	35.00%
Exchange
Deferred Tax Assets Liabilities Net
Net deferred tax liability	$ 250	$ 257
Effective Tax Rate when investment permanent tax differences are considered	35.00%