INVESTMENTS - Net Unrealized Investments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Debt Securities, Available-for-sale, Net Unrealized Investments [Roll Forward]
Beginning of year	$ 15,126	$ 15,432
Deferred income taxes	(382)	(218)
End of year	21,640	14,682
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Net Unrealized Gains (Losses) on Investments
Debt Securities, Available-for-sale, Net Unrealized Investments [Roll Forward]
Beginning of year	3,453	(522)
Net investment gains (losses) arising during the period	1,922	1,710
Included in Net income (loss)	(62)	(1)
Excluded from Net earnings (loss)	0	0
Net unrealized investment gains (losses) excluding OTTI losses	5,313	1,187
Net unrealized investment gains (losses) with OTTI losses	(7)	1
End of year	5,306	1,188
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | DAC
Debt Securities, Available-for-sale, Net Unrealized Investments [Roll Forward]
Beginning of year	(899)	100
DAC	(23)	(701)
Net unrealized investment gains (losses) excluding OTTI losses	(922)	(601)
End of year	(921)	(601)
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Policyholders’ Liabilities
Debt Securities, Available-for-sale, Net Unrealized Investments [Roll Forward]
Beginning of year	(189)	(73)
Policyholders liabilities	(165)	85
Net unrealized investment gains (losses) excluding OTTI losses	(354)	12
End of year	(354)	12
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Deferred Income Tax Asset (Liability)
Debt Securities, Available-for-sale, Net Unrealized Investments [Roll Forward]
Beginning of year	(497)	104
Deferred income taxes	(351)	(230)
Net unrealized investment gains (losses) excluding OTTI losses	(848)	(126)
End of year	(847)	(126)
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)
Debt Securities, Available-for-sale, Net Unrealized Investments [Roll Forward]
Beginning of year	1,868	(391)
Net investment gains (losses) arising during the period	1,922	1,710
Included in Net income (loss)	(62)	(1)
Excluded from Net earnings (loss)	0	0
DAC	(23)	(701)
Deferred income taxes	(351)	(230)
Policyholders liabilities	(165)	85
Net unrealized investment gains (losses) excluding OTTI losses	3,189	472
Net unrealized investment gains (losses) with OTTI losses	(5)	1
End of year	3,184	473
Fixed maturities | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | DAC
Debt Securities, Available-for-sale, Net Unrealized Investments [Roll Forward]
Net unrealized investment gains (losses) with OTTI losses	1	0
Fixed maturities | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Policyholders’ Liabilities
Debt Securities, Available-for-sale, Net Unrealized Investments [Roll Forward]
Net unrealized investment gains (losses) with OTTI losses	0	0
Fixed maturities | AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent | Unrealized Investment Gains Losses All Other | Deferred Income Tax Asset (Liability)
Debt Securities, Available-for-sale, Net Unrealized Investments [Roll Forward]
Net unrealized investment gains (losses) with OTTI losses	$ 1	$ 0