The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

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Investment Holding Level 4 Other-Than-Temporary Impairment Losses (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015	Dec. 31, 2014
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held	$ 178	$ 223	$ 178	$ 223	$ 181	$ 211	$ 270	$ 296
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Held-to-maturity Securities	11	12	20	14
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	12	24	23	32
Other than Temporary Impairment Losses, Investments	12	24	23	32
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, No Previous Impairment	2	0	10	2
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Additions, Additional Credit Losses	9	12	10	12
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Securities Sold	11	49	37	54
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Cash Flows	3	10	16	32
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Reductions, Change in Status	0	0	0	1
Equity Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net	1	4	2	4
Available-for-sale Securities [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Held-to-maturity Securities	$ 0	$ 8	$ 1	$ 14