Investments (Select Information For Securities In A Gross Unrealized Loss Position) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule Of Available For Sale Securities Residential And Commercial Mortgage At Risk [Line Items]
Amortized cost	$ 76,703	$ 73,532
Fair Value	81,019	82,901
Gross Unrealized Losses	1,160	320
AFS Securities Backed By Pools Of Residential Mortgages [Member]
Schedule Of Available For Sale Securities Residential And Commercial Mortgage At Risk [Line Items]
Amortized cost	1,285	1,181
Fair Value	1,163	980
Gross Unrealized Losses	122	201
AFS Securities Backed By Pools Of Commercial Mortgages [Member]
Schedule Of Available For Sale Securities Residential And Commercial Mortgage At Risk [Line Items]
Amortized cost	190	236
Fair Value	163	192
Gross Unrealized Losses	27	44
Total AFS Securities Backed By Pools Of Residential And Commercial Mortgages [Member]
Schedule Of Available For Sale Securities Residential And Commercial Mortgage At Risk [Line Items]
Amortized cost	1,475	1,417
Fair Value	1,326	1,172
Gross Unrealized Losses	149	245
AFS Securities Subject To Detailed Analysis Backed By Pools Of Residential Mortgages [Member]
Schedule Of Available For Sale Securities Residential And Commercial Mortgage At Risk [Line Items]
Amortized cost	1,055	1,173
Fair Value	941	972
Gross Unrealized Losses	114	201
AFS Securities Subject To Detailed Analysis Backed By Pools Of Commercial Mortgages [Member]
Schedule Of Available For Sale Securities Residential And Commercial Mortgage At Risk [Line Items]
Amortized cost	34	56
Fair Value	24	40
Gross Unrealized Losses	10	16
AFS Securities Subject To Detailed Analysis Backed By Pools Of Residential And Commercial Mortgages [Member]
Schedule Of Available For Sale Securities Residential And Commercial Mortgage At Risk [Line Items]
Amortized cost	1,089	1,229
Fair Value	965	1,012
Gross Unrealized Losses	$ 124	$ 217

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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