FAIR VALUE DISCLOSURES - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 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	$ 153	$ 184
Transfers out of Level 3	73	28
Transfers into level 3	$ 14	$ 65
Transfers out of Levels 2 and 3 to total equity (as a percent)	0.60%	0.50%
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	$ 120		$ 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	363		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	$ 1,035		$ 826