FAIR VALUE DISCLOSURES - LEVEL 3 UNOBSERVABLE INPUT RECONCILIATION (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Total gains (losses), realized and unrealized, included in:
Transfers into level 3	$ 67,000,000	$ 15,000,000
Transfers out of Level 3	(16,000,000)	0
Level 3 | Corporate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	1,139,000,000	845,000,000
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	2,000,000	1,000,000
Investment gains (losses), net	0	0
Subtotal	2,000,000	1,000,000
Other comprehensive income (loss)	(20,000,000)	45,000,000
Purchases	173,000,000	169,000,000
Sales	(116,000,000)	(57,000,000)
Settlements	0
Transfers into level 3	67,000,000	11,000,000
Transfers out of Level 3	(16,000,000)	0
Closing Balance	1,229,000,000	1,014,000,000
Level 3 | State and Political Sub- divisions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	40,000,000	42,000,000
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	0	0
Investment gains (losses), net	0	0
Subtotal	0	0
Other comprehensive income (loss)	(1,000,000)	0
Purchases	0	0
Sales	0	0
Settlements	0
Transfers into level 3	0	0
Transfers out of Level 3	0	0
Closing Balance	39,000,000	42,000,000
Level 3 | Commercial Mortgage- backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	0	349,000,000
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	0	0
Investment gains (losses), net	0	31,000,000
Subtotal	0	31,000,000
Other comprehensive income (loss)	0	12,000,000
Purchases	0	0
Sales	0	(68,000,000)
Settlements	0
Transfers into level 3	0	0
Transfers out of Level 3	0	0
Closing Balance	0	324,000,000
Level 3 | Asset- backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	8,000,000	24,000,000
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	0	0
Investment gains (losses), net	0	0
Subtotal	0	0
Other comprehensive income (loss)	0	4,000,000
Purchases	0	0
Sales	(1,000,000)	(1,000,000)
Settlements	0
Transfers into level 3	0	4,000,000
Transfers out of Level 3	0	0
Closing Balance	7,000,000	31,000,000
Level 3 | Redeemable Preferred Stock
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	0	1,000,000
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	0	0
Investment gains (losses), net	0	0
Net derivative gains (losses)	0	0
Subtotal	0	0
Other comprehensive income (loss)	0	0
Purchases	0	0
Sales	0	0
Settlements	0	0
Activity related to consolidated VIEs	0	0
Transfers into level 3	0	0
Transfers out of Level 3	0	0
Closing Balance	0	1,000,000
Level 3 | Other Equity Investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	28,000,000	51,000,000
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	0	0
Investment gains (losses), net	0	0
Net derivative gains (losses)	0	0
Subtotal	0	0
Other comprehensive income (loss)	0	0
Purchases	4,000,000	4,000,000
Sales	0	(1,000,000)
Settlements	0	0
Activity related to consolidated VIEs	1,000,000	0
Transfers into level 3	5,000,000	1,000,000
Transfers out of Level 3	0	0
Closing Balance	38,000,000	55,000,000
Level 3 | GMIB Reinsurance Asset
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	10,488,000,000	10,314,000,000
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	0	0
Investment gains (losses), net	0	0
Net derivative gains (losses)	(842,000,000)	(533,000,000)
Subtotal	(842,000,000)	(533,000,000)
Other comprehensive income (loss)	0	0
Purchases	54,000,000	37,000,000
Sales	(27,000,000)	(21,000,000)
Settlements	0	0
Activity related to consolidated VIEs	0	0
Transfers into level 3	0	0
Transfers out of Level 3	0	0
Closing Balance	9,673,000,000	9,797,000,000
Level 3 | Separate Accounts Assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	349,000,000	313,000,000
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	0	0
Investment gains (losses), net	7,000,000	10,000,000
Net derivative gains (losses)	0	0
Subtotal	7,000,000	10,000,000
Other comprehensive income (loss)	0	0
Purchases	3,000,000	3,000,000
Sales	(1,000,000)	(1,000,000)
Settlements	(1,000,000)	(1,000,000)
Activity related to consolidated VIEs	0	0
Transfers into level 3	0	1,000,000
Transfers out of Level 3	0	0
Closing Balance	357,000,000	325,000,000
Level 3 | GMxB derivative features liability
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	(4,164,000,000)	(5,319,000,000)
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	0	0
Investment gains (losses), net	0	0
Net derivative gains (losses)	440,000,000	490,000,000
Subtotal	440,000,000	490,000,000
Other comprehensive income (loss)	0	0
Purchases	(82,000,000)	(78,000,000)
Sales	2,000,000	1,000,000
Settlements	0	0
Activity related to consolidated VIEs	0	0
Transfers into level 3	0	0
Transfers out of Level 3	0	0
Closing Balance	(3,804,000,000)	(4,906,000,000)
Level 3 | Contingent Payment Arrangement
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Opening Balance	11,000,000	18,000,000
Total gains (losses), realized and unrealized, included in:
Net investment income (loss)	0	0
Investment gains (losses), net	0	0
Net derivative gains (losses)	0	0
Subtotal	0	0
Other comprehensive income (loss)	0	0
Purchases	0	0
Sales	0	0
Settlements	0	(1,000,000)
Activity related to consolidated VIEs	0	0
Transfers into level 3	0	0
Transfers out of Level 3	0	0
Closing Balance	$ 11,000,000	$ 17,000,000