Available-For-Sale Securities (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Schedule of Available-for-sale Securities
Cost Basis	$ 1,495		$ 1,479
Unrealized pretax net gains (losses)	129		107
Fair Value	1,624		1,586
Charges for other than temporary decIines in the value of securities	0	0
U.S. treasury bonds
Schedule of Available-for-sale Securities
Cost Basis	10		10
Unrealized pretax net gains (losses)	0		0
Fair Value	10		10
Other U.S. and non-U.S. government bonds
Schedule of Available-for-sale Securities
Cost Basis	120		144
Unrealized pretax net gains (losses)	2		2
Fair Value	122		146
Corporate bonds
Schedule of Available-for-sale Securities
Cost Basis	638		626
Unrealized pretax net gains (losses)	36		38
Fair Value	674		664
Asset-backed Securities
Schedule of Available-for-sale Securities
Cost Basis	94		96
Unrealized pretax net gains (losses)	0		0
Fair Value	94		96
U.S. governmental agency mortgage-backed securities
Schedule of Available-for-sale Securities
Cost Basis	336		291
Unrealized pretax net gains (losses)	7		8
Fair Value	343		299
Residential
Schedule of Available-for-sale Securities
Cost Basis	24		26
Unrealized pretax net gains (losses)	0		(1)
Fair Value	24		25
Commercial
Schedule of Available-for-sale Securities
Cost Basis	101		117
Unrealized pretax net gains (losses)	9		10
Fair Value	110		127
Large capitalization value
Schedule of Available-for-sale Securities
Cost Basis	151		147
Unrealized pretax net gains (losses)	58		38
Fair Value	209		185
Smaller company growth
Schedule of Available-for-sale Securities
Cost Basis	21		22
Unrealized pretax net gains (losses)	17		12
Fair Value	$ 38		$ 34

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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- Definition

The amount of other than temporary impairment losses on investments in debt and equity securities categorized as Available-for-sale which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) on equity securities, credit losses on investments in debt securities, and when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis.

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