Insurance (Insurance Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	$ 219,144	$ 210,132
Retail
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	91,868	91,575
Group, Voluntary & Worksite Benefits
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	28,805	28,035
Corporate Benefit Funding
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	97,953	89,941
Corporate & Other
Insurance Liabilities [Line Items]
Insurance liabilities comprised of future policy benefits, policyholder account balances and other policy-related balances	$ 518	$ 581