Revenue Recognition (Disaggregated Revenue) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Interest revenue		$ 1,432	$ 1,892	$ 4,626	$ 5,817
Interest expense		(89)	(261)	(322)	(896)
Net interest revenue		1,343	1,631	4,304	4,921
Other	[1]	64	49	161	198
Total net revenues		2,448	2,711	7,515	8,115
Mutual funds, ETFs, and CTFs [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		423	445	1,300	1,287
Advice solutions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		373	305	999	878
Other [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		64	75	189	201
Asset management and administration fees [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		860	825	2,488	2,366
Commissions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		108	159	332	477
Principal Transactions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		6	13	36	54
Order Flow Revenue [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		67	34	194	99
Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	[1]	$ 181	$ 206	$ 562	$ 630

[1] Beginning in the first quarter of 2020, order flow revenue was reclassified from other revenue to trading revenue. Prior period amounts have been reclassified to reflect this change.