INVESTMENTS - Rollforward of Net Unrealized Investment Gains (Losses) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 18,881	$ 12,370	$ 11,658	$ 12,428
Deferred income taxes	(417)	(341)	(820)	(541)
Ending balance	15,166	13,932	15,166	13,932
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | All other | Net Unrealized Gains (Losses) on Investments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	5,040	1,003	3,084	(577)
Net investment gains (losses) arising during the period	3,336	1,623	5,362	3,206
Included in Net income (loss)	(167)	(4)	(230)	(7)
Excluded from Net income (loss)	0	0	0	0
Net unrealized investment gains (losses) excluding OTTI losses	8,209	2,622	8,216	2,622
Net unrealized investment gains (losses) with OTTI losses	(2)	2	(9)	2
Ending balance	8,207	2,624	8,207	2,624
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | All other | DAC
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(205)	(616)	(831)	39
DAC	(289)	82	336	(573)
Net unrealized investment gains (losses) excluding OTTI losses	(494)	(534)	(495)	(534)
Ending balance	(494)	(534)	(494)	(534)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | All other | Policyholders’ Liabilities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(1,003)	22	(192)	(55)
Policyholders’ liabilities	(799)	(108)	(1,611)	(31)
Net unrealized investment gains (losses) excluding OTTI losses	(1,802)	(86)	(1,803)	(86)
Ending balance	(1,801)	(86)	(1,801)	(86)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | All other | Deferred Income Tax Asset (Liability)
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(805)	(86)	(433)	125
Deferred income taxes	(437)	(334)	(810)	(545)
Net unrealized investment gains (losses) excluding OTTI losses	(1,242)	(420)	(1,243)	(420)
Ending balance	(1,242)	(420)	(1,242)	(420)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | 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	3,027	323	1,628	(468)
Net investment gains (losses) arising during the period	3,336	1,623	5,362	3,206
Included in Net income (loss)	(167)	(4)	(230)	(7)
Excluded from Net income (loss)	0	0	0	0
DAC	(289)	82	336	(573)
Deferred income taxes	(437)	(334)	(810)	(545)
Policyholders’ liabilities	(799)	(108)	(1,611)	(31)
Net unrealized investment gains (losses) excluding OTTI losses	4,671	1,582	4,675	1,582
Net unrealized investment gains (losses) with OTTI losses	(1)	2	(5)	2
Ending balance	4,670	1,584	4,670	1,584
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Fixed Maturities | 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	1	0
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Fixed Maturities | 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	2	0
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Fixed Maturities | 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