INVESTMENTS - Net Unrealized Investment (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 15,088	$ 13,781	$ 11,565	$ 12,359
Ending balance	14,399	13,254	14,399	13,254
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Net Unrealized Gains (Losses) on Investments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	8,207	2,622	3,084	(577)
Net investment gains (losses) arising during the period	345	1,548	5,707	4,754
Included in Net income (loss)	(18)	(201)	(248)	(208)
Excluded from Net income (loss)	0	0	0	0
Impact of net unrealized investment gains (losses)	0	0	0	0
Net unrealized investment gains (losses) excluding OTTI losses	8,534	3,969	8,543	3,969
Net unrealized investment gains (losses) with OTTI losses	3	1	(6)	1
Ending balance	8,537	3,970	8,537	3,970
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | DAC
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(494)	(616)	(826)	37
Impact of net unrealized investment gains (losses)	54	(324)	386	(977)
Net unrealized investment gains (losses) excluding OTTI losses	(440)	(940)	(440)	(940)
Ending balance	(440)	(940)	(440)	(940)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Policyholders’ Liabilities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(1,801)	(98)	(192)	(69)
Impact of net unrealized investment gains (losses)	(6)	(122)	(1,617)	(151)
Net unrealized investment gains (losses) excluding OTTI losses	(1,807)	(220)	(1,809)	(220)
Ending balance	(1,808)	(220)	(1,808)	(220)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Deferred Income Tax Asset (Liability)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(1,242)	(420)	(433)	125
Impact of net unrealized investment gains (losses)	(79)	(156)	(889)	(701)
Net unrealized investment gains (losses) excluding OTTI losses	(1,321)	(576)	(1,322)	(576)
Ending balance	(1,321)	(576)	(1,321)	(576)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | AOCI Gain (Loss) Related to Net Unrealized Investment Gains (Losses)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	4,670	1,488	1,633	(484)
Net investment gains (losses) arising during the period	345	1,548	5,707	4,754
Included in Net income (loss)	(18)	(201)	(248)	(208)
Excluded from Net income (loss)	0	0	0	0
Impact of net unrealized investment gains (losses)	(31)	(602)	(2,120)	(1,829)
Net unrealized investment gains (losses) excluding OTTI losses	4,966	2,233	4,972	2,233
Net unrealized investment gains (losses) with OTTI losses	2	1	(4)	1
Ending balance	4,968	2,234	4,968	2,234
Fixed Maturities | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | DAC
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Net unrealized investment gains (losses) with OTTI losses	0	0	0	0
Fixed Maturities | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Policyholders’ Liabilities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Net unrealized investment gains (losses) with OTTI losses	(1)	0	1	0
Fixed Maturities | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Deferred Income Tax Asset (Liability)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Net unrealized investment gains (losses) with OTTI losses	$ 0	$ 0	$ 1	$ 0