FAIR VALUE DISCLOSURES - ASSETS AND LIABILITIES MEASURED ON RECURRING BASIS (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fixed maturities, available-for-sale	$ 36,515	$ 32,683
Fair value of freestanding derivative positions	$ 1,953	$ 51
Fair value of freestanding derivative positions (percentage)	48.50%	8.20%
Fair value adjustments on GMIB asset	$ 69	$ 139
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
AFS fixed maturities transferred from Level 3 to Level 2	$ 6	62	$ 125
AFS fixed maturities transferred from Level 3 to Level 2		$ 25	$ 99
AFS fixed maturities transferred between Level 2 and 3 (percentage)	0.10%	0.90%	1.30%
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Assets measured at fair value on recurring basis by inputs level (percentage)	69.20%	71.10%
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Assets measured at fair value on recurring basis by inputs level (percentage)	29.90%	27.90%
Owned mortgages and asset-backed securities including CMBS at fair value	$ 257	$ 340
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Assets measured at fair value on recurring basis by inputs level (percentage)	0.90%	1.00%
Owned mortgages and asset-backed securities including CMBS at fair value	$ 8	$ 373
Fixed maturities fair value, broker priced	97	111
Other invested assets	2
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
AFS fixed maturities transferred from Level 3 to Level 2	7
Public Fixed Maturities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fixed maturities, available-for-sale	$ 28,826	$ 24,918
Fixed maturities, available for sale (percentage)	16.20%	16.00%
Private Fixed Maturities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fixed maturities, available-for-sale	$ 7,532	$ 7,652
Fixed maturities, available for sale (percentage)	4.20%	4.90%
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net [Abstract]
AFS fixed maturities transferred from Level 3 to Level 2		$ 56
Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fixed maturities, available-for-sale	$ 36,358	32,570
Other invested assets	4,023	1,218
Fair Value, Measurements, Recurring | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fixed maturities, available-for-sale	180	218
Other invested assets	1,058	342
Fair Value, Measurements, Recurring | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fixed maturities, available-for-sale	34,991	31,091
Other invested assets	2,938	830
Fair Value, Measurements, Recurring | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fixed maturities, available-for-sale	1,187	1,261
Other invested assets	27	46
Fair Value, Measurements, Recurring | Assets of consolidated VIEs/VOEs
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Other invested assets	1,302	593
Fair Value, Measurements, Recurring | Assets of consolidated VIEs/VOEs | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Other invested assets	1,060	342
Fair Value, Measurements, Recurring | Assets of consolidated VIEs/VOEs | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Other invested assets	215	205
Fair Value, Measurements, Recurring | Assets of consolidated VIEs/VOEs | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Other invested assets	$ 27	$ 46