CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Millions	Total	Cumulative effect of period of adoption, adjusted balance	Parent	Parent Cumulative effect of period of adoption, adjusted balance	Preferred Stock and Additional Paid-In Capital	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Retained Earnings Cumulative effect of period of adoption, adjusted balance	AOCI Attributable to Parent	Non-controlling Interest
Beginning of year at Dec. 31, 2018	$ 15,432		$ 13,866		$ 0	$ 5	$ 1,908	$ (640)	$ 13,989		$ (1,396)	$ 1,566
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	23		11				9	2				12
Purchase of treasury stock	(594)		(594)					(594)
Retirement of common stock	(143)		(143)						(143)
Repurchase of AB Holding units	(21)											(21)
Dividends paid to noncontrolling interest	(124)											(124)
Dividends	(141)		(141)						(141)
Net income (loss)	(298)		(412)						(412)			114
Other comprehensive income (loss)	2,270		2,272								2,272	(2)
Other	(16)		(16)				(16)
End of year at Jun. 30, 2019	16,388		14,843		0	5	1,901	(1,232)	13,293		876	1,545
Beginning of year at Mar. 31, 2019	14,682		13,143		0	5	1,881	(1,234)	13,004		(513)	1,539
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	33		30				28	2				3
Retirement of common stock	(1)		(1)						(1)
Dividends paid to noncontrolling interest	(56)											(56)
Dividends	(73)		(73)						(73)
Net income (loss)	423		363						363			60
Other comprehensive income (loss)	1,388		1,389								1,389	(1)
Other	(8)		(8)				(8)
End of year at Jun. 30, 2019	16,388		14,843		0	5	1,901	(1,232)	13,293		876	1,545
Beginning of year at Dec. 31, 2019	15,126	$ (30)	13,535	$ (30)	775	5	1,920	(1,832)	11,827	$ (30)	840	1,591
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	49		44				29	15				5
Purchase of treasury stock	(230)		(230)					(230)
Reissuance of treasury stock	(15)		(15)						(15)
Repurchase of AB Holding units	(48)		(31)				(31)					(17)
Dividends paid to noncontrolling interest	(162)											(162)
Dividends	(146)		(146)						(146)
Dividends on preferred stock	(23)		(23)						(23)
Net income (loss)	1,510		1,382						1,382			128
Other comprehensive income (loss)	3,083		3,088								3,088	(5)
Other	20		20				20
End of year at Jun. 30, 2020	$ 19,134		17,594		775	5	1,938	(2,047)	12,995		3,928	1,540
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting standards update [extensible list]	us-gaap:AccountingStandardsUpdate201613Member
Beginning of year at Mar. 31, 2020	$ 21,640		20,086		775	5	1,930	(2,025)	17,112		2,289	1,554
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock compensation	19		17				15	2				2
Purchase of treasury stock	(24)		(24)					(24)
Reissuance of treasury stock	(2)		(2)						(2)
Repurchase of AB Holding units	(48)		(37)				(37)					(11)
Dividends paid to noncontrolling interest	(69)											(69)
Dividends	(77)		(77)						(77)
Dividends on preferred stock	(10)		(10)						(10)
Net income (loss)	(3,967)		(4,028)						(4,028)			61
Other comprehensive income (loss)	1,642		1,639								1,639	3
Other	30		30				30
End of year at Jun. 30, 2020	$ 19,134		$ 17,594		$ 775	$ 5	$ 1,938	$ (2,047)	$ 12,995		$ 3,928	$ 1,540