Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

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

+ References

No definition available.

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Amount of equity securities categorized neither as held-to-maturity nor as trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
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-Name Accounting Standards Codification
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-SubTopic 320
-Section 50
-Paragraph 2
-Subparagraph (a)
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 30
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14172-108612

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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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Fair Value Measurements Level 4 Fair Value Option (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Fair Value, Option, Quantitative Disclosures [Line Items]
Available-for-sale Securities, Equity Securities	$ 1,223		$ 1,097
Available-for-sale Equity Securities, Amortized Cost Basis	1,135		1,020
Fair Value of Assets Accounted for Using Fair Value Option	176,276		172,243
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(1)	$ (34)
Corporate Debt Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(1)	0
Foreign Government Debt Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	0	(1)
Residential Mortgage Backed Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	1	1
Fixed Maturities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value, Option, Changes in Fair Value, Gain (Loss)	0	0
Equity Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Available-for-sale Securities, Equity Securities	123		0
Available-for-sale Equity Securities, Amortized Cost Basis	124
Fair Value, Option, Changes in Fair Value, Gain (Loss)	(1)	$ (34)
Equity Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Assets Accounted for Using Fair Value Option	123		0
Fixed Maturities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Assets Accounted for Using Fair Value Option	160		293
Fixed Maturities [Member] \| Asset-backed Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Assets Accounted for Using Fair Value Option	0		7
Fixed Maturities [Member] \| Corporate Debt Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Assets Accounted for Using Fair Value Option	0		40
Fixed Maturities [Member] \| Collateralized Debt Obligations [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Assets Accounted for Using Fair Value Option	0		3
Fixed Maturities [Member] \| Commercial Mortgage Backed Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Assets Accounted for Using Fair Value Option	0		8
Fixed Maturities [Member] \| Residential Mortgage Backed Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Assets Accounted for Using Fair Value Option	160		228
Fixed Maturities [Member] \| US Treasury Bond Securities [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Fair Value of Assets Accounted for Using Fair Value Option	$ 0		$ 7