EQUITY - Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended							6 Months Ended		9 Months Ended				12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019		Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2020		Sep. 30, 2019		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Comprehensive Income (Loss), Tax [Abstract]
Net unrealized gains (losses) arising during the period	$ 295			$ 1,224						$ 4,524		$ 3,750
(Gains) losses reclassified into net income (loss) during the period	(23)			(159)						(205)		(157)
Net unrealized gains (losses) on investments	271			1,065						4,318		3,593
Adjustments for policyholders’ liabilities, DAC, insurance liability loss recognition and other	(24)			(335)						(992)		(872)
Change in unrealized gains (losses), net of adjustments (net of deferred income tax expense (benefit) of 66, $194, $884 and $718)	247	$ 1,569	$ 1,510	730	[1]	$ 1,226	$ 765	$ 3,079	$ 1,991	3,327	[1]	2,721	[1]	$ 2,095	$ (1,221)	$ 564
Other comprehensive income (loss), attributable to Equitable Financial	247			730						3,327		2,721
Deferred income taxes	66			194						884		718
Unrealized gains (losses) on investments
Other Comprehensive Income (Loss), Tax [Abstract]
Reclassification from AOCI, current period, tax	$ (6)			$ (42)						$ (55)		$ (42)

[1] See Note 11 for details of Change in unrealized gains (losses), net of adjustments.