DERIVATIVE INSTRUMENTS - Gains (Losses) Recognized on Fair Value Hedging Relationships (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fixed-maturity securities and equity securities \| Foreign currency forwards
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized for derivatives	$ 98	$ 207
Gains (losses) on derivatives excluded from effectiveness testing	(202)	(338)
Gains (losses) on derivatives included in effectiveness testing	300	545
Gains (losses) recognized for hedged items	(278)	(566)
Ineffectiveness recognized for fair value hedge	22	(21)
Fixed maturities \| Foreign currency forwards
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized for derivatives			$ (133)
Gains (losses) on derivatives excluded from effectiveness testing			(136)
Gains (losses) on derivatives included in effectiveness testing			3
Gains (losses) recognized for hedged items			(5)
Ineffectiveness recognized for fair value hedge			(2)
Fixed maturities \| Foreign currency options
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized for derivatives	21	(95)	(4)
Gains (losses) on derivatives excluded from effectiveness testing	10	(18)	3
Gains (losses) on derivatives included in effectiveness testing	11	(77)	(7)
Gains (losses) recognized for hedged items	(10)	70	7
Ineffectiveness recognized for fair value hedge	$ 1	$ (7)	0
Fixed maturities \| Interest rate swaptions
Derivative Instruments, Gain (Loss) [Line Items]
Total gains (losses) recognized for derivatives			(95)
Gains (losses) on derivatives excluded from effectiveness testing			19
Gains (losses) on derivatives included in effectiveness testing			(114)
Gains (losses) recognized for hedged items			99
Ineffectiveness recognized for fair value hedge			$ (15)

Gain (loss) from components included in assessment of fair value hedge effectiveness net

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- Definition

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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- Definition

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

+ References

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- Definition

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.

+ References

No definition available.

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- Definition

Net gain (loss) relating to components of the gain (loss) on the fair value hedging instrument excluded from the assessment of fair value hedge effectiveness. Recognized in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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- Definition

Amount of gain (loss)recognized in the income statement from the hedging ineffectiveness of a fair value hedge.

+ References

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