Insurance (Details 4) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Fixed maturity securities [Member]
Separate Accounts
Proportional interest in separate accounts	$ 0	$ 257
Equity Securities [Member]
Separate Accounts
Proportional interest in separate accounts	0	33
Cash and Cash Equivalents [Member]
Separate Accounts
Proportional interest in separate accounts	$ 0	$ 74