INSURANCE LIABILITIES AND ANNUITY BENEFITS - Schedule of Investment Contracts, Insurance Liabilities and Insurance Annuity Benefits (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Liability for Claims and Claims Adjustment Expense [Line Items]
Future policy benefit reserves	$ 33,742	$ 32,104
Other adjustments	7,404	5,655
Claim reserves	5,713	5,615
Investment contracts	2,094	2,191
Unearned premiums and other	327	322
Future policy benefit reserves, investment contracts, claim reserves and unearned premiums and other	41,876	40,232
Eliminations	(424)	(406)
Total	41,452	39,826
Long-term care insurance contracts
Liability for Claims and Claims Adjustment Expense [Line Items]
Future policy benefit reserves	16,866	16,755
Claim reserves	4,364	4,238
Investment contracts	0	0
Unearned premiums and other	20	30
Future policy benefit reserves, investment contracts, claim reserves and unearned premiums and other	21,250	21,023
Total	21,250	21,023
Structured settlement annuities & life insurance contracts
Liability for Claims and Claims Adjustment Expense [Line Items]
Future policy benefit reserves	9,294	9,511
Claim reserves	270	252
Investment contracts	1,060	1,136
Unearned premiums and other	189	196
Future policy benefit reserves, investment contracts, claim reserves and unearned premiums and other	10,813	11,095
Total	10,813	11,095
Other contracts
Liability for Claims and Claims Adjustment Expense [Line Items]
Future policy benefit reserves	178	183
Claim reserves	1,079	1,125
Investment contracts	1,034	1,055
Unearned premiums and other	118	96
Future policy benefit reserves, investment contracts, claim reserves and unearned premiums and other	2,409	2,459
Eliminations	(424)	(406)
Total	$ 1,985	$ 2,053