FAIR VALUE DISCLOSURES - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fair value adjustments on GMIB asset	$ 148	$ 184
Transfers out of Level 3	69	16
Transfers into level 3	$ 17	$ 67
Transfers out of Levels 2 and 3 to total equity (as a percent)	0.70%	0.40%
Level 3 | Corporate | Matrix pricing model
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fair value of privately placed, available-for-sale corporate debt securities classified as Level 3	$ 96		$ 93
Level 3 | Separate Accounts Assets | Third party appraisal
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fair value of privately placed, available-for-sale corporate debt securities classified as Level 3	359		352
Fair Value, Measurements, Nonrecurring | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Quantitative Disclosure [Line Items]
Fair Value Measurements Not Included In Quantitative Information About Level 3 Fair Value Measurements	$ 796		$ 826