Net realized gains losses and change in net unrealized appreciation depreciation

No definition available.

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This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

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Amount of loss realized on the sale of debt or equity securities classified as available-for-sale. Excludes other than temporary impairments (OTTI).

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No definition available.

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- Definition

This item represents the gain (loss) realized during the period from the sale of investments accounted for under the cost method of accounting and any losses recognized thereon for impairments of other than a temporary nature.

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- Definition

For investments in debt and equity securities accounted for at cost, the excess of net sale proceeds over the carrying amount of investments disposed of during the period.

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This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the cost method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

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For investments in debt and equity securities accounted for at cost, the excess of the carrying amount over net sale proceeds of investments disposed of during the period.

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- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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For each line item in the statement of financial position, the amounts of gains and losses from fair value changes included in earnings.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition

Amount before tax of foreign currency transaction realized and unrealized gain (loss) recognized in the income statement.

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- Definition

This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting and losses recognized for other than temporary impairments (OTTI) of the subject investments.

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Amount of gain (loss) included in earnings for investments classified as other.

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This element represents the amount of loss recognized for other than temporary impairments (OTTI) of investments in debt and equity securities.

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- Definition

Amount of tax expense (benefit), after reclassification adjustments, of appreciation (loss) in value of unsold available-for-sale securities. Excludes amounts related to other than temporary impairment (OTTI) loss.

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Amount before tax of other than temporary impairment (OTTI) loss on investments in available-for-sale and held-to-maturity debt securities, recognized in other comprehensive loss.

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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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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of investments, not including unrealized gains or losses on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, held at each balance sheet date and included in earnings for the period.

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Investments (Net Realized Gains (Losses) And Losses Included In Net Realized Gains (Losses) And Other Comprehensive Income) (Detail) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment (OTTI) losses gross									$ (46)	$ (111)	$ (151)
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, before Tax, Including Portion Attributable to Noncontrolling Interest									1	8	39
Foreign exchange gains( losses)									36	118	(80)
Fair Value adjustment on insurance derivative									364	53	(203)
Derivative, Gain (Loss) on Derivative, Net									87	(126)	(193)
Total Net realized gains (losses) including OTTI	$ 0	$ (10)	$ 101	$ (7)	$ 365	$ 100	$ (216)	$ (394)	84	(145)	(420)
Unrealized Gain (Loss) on Investments									392	184	(977)
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax									(241)	100	152
Total net realized gains (losses) and change in net unrealized appreciation (depreciation) on investments									476	39	(1,397)
Other derivative instruments
Gain (Loss) on Investments [Line Items]
Derivative, Gain (Loss) on Derivative, Net									(5)	(10)	(12)
Investment and embedded derivative instruments
Gain (Loss) on Investments [Line Items]
Derivative, Gain (Loss) on Derivative, Net									(11)	(33)	32
S&P Options and Futures
Gain (Loss) on Investments [Line Items]
Derivative, Gain (Loss) on Derivative, Net									(261)	(136)	(10)
Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
Cost-method Investments, Other than Temporary Impairment									(10)	(8)	(7)
Equity Securities - Gross Realized Gains Excluding OTTI									28	65	47
Equity Securities - Gross realized losses excluding OTTI									(2)	(13)	(11)
Total Equity Securities									16	44	29
Unrealized Gain (Loss) on Investments									88	52	(17)
Fixed maturities held to maturity
Gain (Loss) on Investments [Line Items]
Unrealized Gain (Loss) on Investments									18	(59)	43
Other Investments [Member]
Gain (Loss) on Investments [Line Items]
Cost-method Investments, Other than Temporary Impairment									(12)	(14)	(2)
Gain (Loss) on Sale of Other Investments									(12)	(4)	6
Unrealized Gain (Loss) on Investments									8	(51)	(36)
Available-for-sale Securities [Member]
Gain (Loss) on Investments [Line Items]
Unrealized Gain (Loss) on Investments									519	142	(1,119)
Debt Securities [Member]
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment (OTTI) losses gross									(24)	(89)	(142)
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, before Tax, Including Portion Attributable to Noncontrolling Interest									1	8	39
Other than Temporary Impairment Losses, Investments, Portion Recognized in Earnings, Net, Available-for-sale Securities									(23)	(81)	(103)
Available-for-sale Securities, Gross Realized Gains									149	183	158
Available-for-sale Securities, Gross Realized Losses									(157)	(265)	(235)
Available-for-sale Securities, Gross Realized Gain (Loss)									$ (31)	$ (163)	$ (180)