Revenue Recognition (Disaggregated Revenue) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Disaggregation of Revenue [Line Items]
Interest revenue		$ 1,708	$ 1,998
Interest expense		(136)	(317)
Net interest revenue		1,572	1,681
Other (1)	[1]	30	70
Total net revenues		2,617	2,723
Mutual funds, ETFs, and CTFs [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		452	414
Advice solutions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		312	278
Other [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		63	63
Asset management and administration fees [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		827	755
Commissions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		113	163
Principal Transactions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		20	22
Order Flow Revenue [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue		55	32
Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue	[1]	$ 188	$ 217

[1] 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.