Revenue Recognition (Disaggregated Revenue) (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Interest revenue	$ 1,486		$ 1,927		$ 3,194	$ 3,925
Interest expense	(97)		(318)		(233)	(635)
Net interest revenue	1,389		1,609		2,961	3,290
Other	67	[1]	79	[1]	97	149
Total net revenues	2,450		2,681		5,067	5,404
Mutual funds, ETFs, and CTFs [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	425		428		877	842
Advice solutions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	314		295		626	573
Other [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	62		63		125	126
Asset management and administration fees [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	801		786		1,628	1,541
Commissions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	111		155		224	318
Principal Transactions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	10		19		30	41
Order Flow Revenue [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	72		33		127	65
Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	$ 193	[1]	$ 207	[1]	$ 381	$ 424

[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.