Revenue Recognition (Disaggregated Revenue) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Interest revenue									$ 7,580	$ 6,680	$ 4,624
Interest expense									(1,064)	(857)	(342)
Net interest revenue									6,516	5,823	4,282
Other									377	317	290
Total net revenues	$ 2,606	$ 2,711	$ 2,681	$ 2,723	$ 2,669	$ 2,579	$ 2,486	$ 2,398	10,721	10,132	8,618
Asset Management and administration fees [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue									3,211	3,229	3,392
Mutual funds, ETFs, and CTFs [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue									1,747	1,837	2,088
Advice solutions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue									1,198	1,139	1,043
Other [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue									266	253	261
Trading revenue [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue									617	763	654
Commissions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue									549	685	600
Principal Transactions [Member]
Disaggregation of Revenue [Line Items]
Asset management and administration fees and Trading revenue									$ 68	$ 78	$ 54