CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions	Total	Parent	Preferred Stock and Additional Paid-In Capital	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	AOCI Attributable to Parent	Non-controlling Interest
Beginning of year at Dec. 31, 2016	$ 16,518	$ 13,421		$ 5	$ 1,299	$ 0	$ 12,225	$ (108)	$ 3,097
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Repurchase of AB Holding units	(95)								(95)
Dividends paid to noncontrolling interest	(346)								(346)
Net income (loss)	2,136	1,820					1,820		316
Other comprehensive income (loss)	(1,177)	(1,192)						(1,192)	15
Other	(18)	(103)							85
End of year at Dec. 31, 2017	17,018	13,946		5	1,196	0	14,045	(1,300)	3,072
Beginning of year at Dec. 31, 2018	15,432	13,866		5	1,908	(640)	13,989	(1,396)	1,566
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	(10)	(19)			(19)				9
Purchase of treasury stock	(594)	(594)				(594)
Retirement of common stock	(142)	(142)					(142)
Repurchase of AB Holding units	(21)								(21)
Dividends paid to noncontrolling interest	(68)								(68)
Dividends	(68)	(68)					(68)
Net income (loss)	(721)	(775)					(775)		54
Other comprehensive income (loss)	882	883						883	(1)
Other	(8)	(8)			(8)
End of year at Mar. 31, 2019	14,682	13,143		5	1,881	(1,234)	13,004	(513)	1,539
Beginning of year at Dec. 31, 2019	15,126	13,535	$ 775	5	1,920	(1,832)	11,827	840	1,591
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	30	27			14	13			3
Purchase of treasury stock	(206)	(206)				(206)
Reissuance of treasury stock	(13)	(13)					(13)
Repurchase of AB Holding units	0	6			6				(6)
Dividends paid to noncontrolling interest	(93)								(93)
Dividends	(69)	(69)					(69)
Dividends on preferred stock	(13)	(13)					(13)
Net income (loss)	5,477	5,410					5,410		67
Other comprehensive income (loss)	1,441	1,449						1,449	(8)
Other	(10)	(10)			(10)
End of year at Mar. 31, 2020	$ 21,640	$ 20,086	$ 775	$ 5	$ 1,930	$ (2,025)	$ 17,112	$ 2,289	$ 1,554