INSURANCE LIABILITIES - Variable Annuity Contracts with GMDB and GMIB Features and Buybacks (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
GMDB
Net Amount at Risk by Product and Guarantee [Line Items]
Separate Accounts	$ 78,940	$ 94,488
GMDB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	14,988
Separate Accounts	78,940
Net Amount At Risk By Product And Guarantee, Account Value	93,928
Net Amount at Risk, gross	26,769
Net Amount at Risk, net of amounts reinsured	$ 26,100
Average attained age of contractholders (in years)	55 years 1 month 6 days
Percentage of policyholders over age 70	19.50%
GMDB | Direct Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.00%
GMDB | Direct Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.50%
GMDB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 6,299
Net Amount at Risk, gross	$ 925
Average attained age of contractholders (in years)	73 years
Percentage of policyholders over age 70	65.00%
GMDB | Deferred Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.00%
GMDB | Deferred Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	10.00%
GMIB
Net Amount at Risk by Product and Guarantee [Line Items]
Separate Accounts	$ 50,200	$ 59,348
GMIB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	246
Separate Accounts	50,200
Net Amount At Risk By Product And Guarantee, Account Value	50,446
Net Amount at Risk, gross	18,928
Net Amount at Risk, net of amounts reinsured	$ 16,199
Average attained age of contractholders (in years)	69 years 7 months 6 days
Weighted average years remaining until annuitization (in years)	4 months 24 days
GMIB | Direct Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.00%
GMIB | Direct Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.50%
GMIB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 1,927
Net Amount at Risk, gross	$ 496
Average attained age of contractholders (in years)	71 years
Percentage of policyholders over age 70	59.10%
GMIB | Deferred Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.30%
GMIB | Deferred Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.50%
Return of Premium | GMDB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 14,662
Separate Accounts	40,733
Net Amount At Risk By Product And Guarantee, Account Value	55,395
Net Amount at Risk, gross	715
Net Amount at Risk, net of amounts reinsured	$ 715
Average attained age of contractholders (in years)	51 years 1 month 6 days
Percentage of policyholders over age 70	10.70%
Return of Premium | GMDB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 776
Net Amount at Risk, gross	$ 13
Average attained age of contractholders (in years)	68 years
Percentage of policyholders over age 70	46.30%
Return of Premium | GMIB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 0
Separate Accounts	0
Net Amount At Risk By Product And Guarantee, Account Value	0
Net Amount at Risk, gross	0
Net Amount at Risk, net of amounts reinsured	0
Return of Premium | GMIB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	744
Net Amount at Risk, gross	$ 2
Average attained age of contractholders (in years)	72 years
Percentage of policyholders over age 70	65.10%
Ratchet | GMDB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 92
Separate Accounts	7,887
Net Amount At Risk By Product And Guarantee, Account Value	7,979
Net Amount at Risk, gross	877
Net Amount at Risk, net of amounts reinsured	$ 857
Average attained age of contractholders (in years)	67 years 9 months 18 days
Percentage of policyholders over age 70	46.40%
Ratchet | GMDB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 4,352
Net Amount at Risk, gross	$ 627
Average attained age of contractholders (in years)	73 years
Percentage of policyholders over age 70	65.20%
Ratchet | GMIB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 0
Separate Accounts	0
Net Amount At Risk By Product And Guarantee, Account Value	0
Net Amount at Risk, gross	0
Net Amount at Risk, net of amounts reinsured	0
Ratchet | GMIB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	37
Net Amount at Risk, gross	$ 3
Average attained age of contractholders (in years)	74 years
Percentage of policyholders over age 70	62.80%
Roll-Up | GMDB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 58
Separate Accounts	2,607
Net Amount At Risk By Product And Guarantee, Account Value	2,665
Net Amount at Risk, gross	2,296
Net Amount at Risk, net of amounts reinsured	$ 1,647
Average attained age of contractholders (in years)	74 years 4 months 24 days
Percentage of policyholders over age 70	68.70%
Roll-Up | GMDB | Direct Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.00%
Roll-Up | GMDB | Direct Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.00%
Roll-Up | GMDB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 225
Net Amount at Risk, gross	$ 22
Average attained age of contractholders (in years)	78 years
Percentage of policyholders over age 70	80.70%
Roll-Up | GMDB | Deferred Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.00%
Roll-Up | GMDB | Deferred Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	10.00%
Roll-Up | GMIB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 18
Separate Accounts	20,724
Net Amount At Risk By Product And Guarantee, Account Value	20,742
Net Amount at Risk, gross	1,360
Net Amount at Risk, net of amounts reinsured	$ 425
Average attained age of contractholders (in years)	68 years 10 months 25 days
Weighted average years remaining until annuitization (in years)	1 year 7 months 6 days
Roll-Up | GMIB | Direct Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.00%
Roll-Up | GMIB | Direct Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.00%
Roll-Up | GMIB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 190
Net Amount at Risk, gross	$ 46
Average attained age of contractholders (in years)	72 years
Percentage of policyholders over age 70	61.50%
Roll-Up | GMIB | Deferred Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.30%
Roll-Up | GMIB | Deferred Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.50%
Combo | GMDB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 176
Separate Accounts	27,713
Net Amount At Risk By Product And Guarantee, Account Value	27,889
Net Amount at Risk, gross	22,881
Net Amount at Risk, net of amounts reinsured	$ 22,881
Average attained age of contractholders (in years)	69 years 7 months 6 days
Percentage of policyholders over age 70	51.60%
Combo | GMDB | Direct Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.00%
Combo | GMDB | Direct Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.50%
Combo | GMDB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 946
Net Amount at Risk, gross	$ 263
Average attained age of contractholders (in years)	76 years
Percentage of policyholders over age 70	75.80%
Combo | GMDB | Deferred Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	5.00%
Combo | GMDB | Deferred Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	10.00%
Combo | GMIB | Direct Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 228
Separate Accounts	29,476
Net Amount At Risk By Product And Guarantee, Account Value	29,704
Net Amount at Risk, gross	17,568
Net Amount at Risk, net of amounts reinsured	$ 15,774
Average attained age of contractholders (in years)	69 years 8 months 12 days
Weighted average years remaining until annuitization (in years)	3 months 19 days
Combo | GMIB | Direct Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	3.00%
Combo | GMIB | Direct Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.50%
Combo | GMIB | Deferred Variable Annuity
Net Amount at Risk by Product and Guarantee [Line Items]
General Account	$ 956
Net Amount at Risk, gross	$ 445
Average attained age of contractholders (in years)	69 years
Percentage of policyholders over age 70	53.80%
Combo | GMIB | Deferred Variable Annuity | Minimum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.00%
Combo | GMIB | Deferred Variable Annuity | Maximum
Net Amount at Risk by Product and Guarantee [Line Items]
Range of contractually specified interest rates (as a percent)	6.00%