Exit and Other Related Liabilities (Summary of the Cumulative Acquisition-Related Exit Costs) (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	$ 47	$ 90
Cumulative exit and other related costs incurred to date	276	276
Compensation and benefits [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	44	72
Cumulative exit and other related costs incurred to date	248	248
Occupancy and equipment [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	3	16
Cumulative exit and other related costs incurred to date	23	23
Depreciation and amortization [Member]
Restructuring Cost and Reserve [Line Items]
Cumulative exit and other related costs incurred to date	3	3
Professional services [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		1
Cumulative exit and other related costs incurred to date	1	1
Other [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		1
Cumulative exit and other related costs incurred to date	1	1
Investor Services [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	38	72
Cumulative exit and other related costs incurred to date	218	218
Investor Services [Member] | Compensation and benefits [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	35	57
Cumulative exit and other related costs incurred to date	195	195
Investor Services [Member] | Occupancy and equipment [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	3	13
Cumulative exit and other related costs incurred to date	19	19
Investor Services [Member] | Depreciation and amortization [Member]
Restructuring Cost and Reserve [Line Items]
Cumulative exit and other related costs incurred to date	2	2
Investor Services [Member] | Professional services [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		1
Cumulative exit and other related costs incurred to date	1	1
Investor Services [Member] | Other [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		1
Cumulative exit and other related costs incurred to date	1	1
Investor Services [Member] | Employee Compensation and Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	35	57
Cumulative exit and other related costs incurred to date	195	195
Investor Services [Member] | Employee Compensation and Benefits [Member] | Compensation and benefits [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	35	57
Cumulative exit and other related costs incurred to date	195	195
Investor Services [Member] | Employee Compensation and Benefits [Member] | Occupancy and equipment [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	0	0
Cumulative exit and other related costs incurred to date	0	0
Investor Services [Member] | Employee Compensation and Benefits [Member] | Depreciation and amortization [Member]
Restructuring Cost and Reserve [Line Items]
Cumulative exit and other related costs incurred to date	0	0
Investor Services [Member] | Employee Compensation and Benefits [Member] | Professional services [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		0
Cumulative exit and other related costs incurred to date	0	0
Investor Services [Member] | Employee Compensation and Benefits [Member] | Other [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		0
Cumulative exit and other related costs incurred to date	0	0
Investor Services [Member] | Facility Exit Costs [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	3	15
Cumulative exit and other related costs incurred to date	23	23
Investor Services [Member] | Facility Exit Costs [Member] | Compensation and benefits [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	0	0
Cumulative exit and other related costs incurred to date	0	0
Investor Services [Member] | Facility Exit Costs [Member] | Occupancy and equipment [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	3	13
Cumulative exit and other related costs incurred to date	19	19
Investor Services [Member] | Facility Exit Costs [Member] | Depreciation and amortization [Member]
Restructuring Cost and Reserve [Line Items]
Cumulative exit and other related costs incurred to date	2	2
Investor Services [Member] | Facility Exit Costs [Member] | Professional services [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		1
Cumulative exit and other related costs incurred to date	1	1
Investor Services [Member] | Facility Exit Costs [Member] | Other [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		1
Cumulative exit and other related costs incurred to date	1	1
Advisor Services [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	9	18
Cumulative exit and other related costs incurred to date	58	58
Advisor Services [Member] | Compensation and benefits [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	9	15
Cumulative exit and other related costs incurred to date	53	53
Advisor Services [Member] | Occupancy and equipment [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	0	3
Cumulative exit and other related costs incurred to date	4	4
Advisor Services [Member] | Depreciation and amortization [Member]
Restructuring Cost and Reserve [Line Items]
Cumulative exit and other related costs incurred to date	1	1
Advisor Services [Member] | Professional services [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		0
Cumulative exit and other related costs incurred to date	0	0
Advisor Services [Member] | Other [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		0
Cumulative exit and other related costs incurred to date	0	0
Advisor Services [Member] | Employee Compensation and Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	9	15
Cumulative exit and other related costs incurred to date	53	53
Advisor Services [Member] | Employee Compensation and Benefits [Member] | Compensation and benefits [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	9	15
Cumulative exit and other related costs incurred to date	53	53
Advisor Services [Member] | Employee Compensation and Benefits [Member] | Occupancy and equipment [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	0	0
Cumulative exit and other related costs incurred to date	0	0
Advisor Services [Member] | Employee Compensation and Benefits [Member] | Depreciation and amortization [Member]
Restructuring Cost and Reserve [Line Items]
Cumulative exit and other related costs incurred to date	0	0
Advisor Services [Member] | Employee Compensation and Benefits [Member] | Professional services [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		0
Cumulative exit and other related costs incurred to date	0	0
Advisor Services [Member] | Employee Compensation and Benefits [Member] | Other [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		0
Cumulative exit and other related costs incurred to date	0	0
Advisor Services [Member] | Facility Exit Costs [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	0	3
Cumulative exit and other related costs incurred to date	5	5
Advisor Services [Member] | Facility Exit Costs [Member] | Compensation and benefits [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	0	0
Cumulative exit and other related costs incurred to date	0	0
Advisor Services [Member] | Facility Exit Costs [Member] | Occupancy and equipment [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period	0	3
Cumulative exit and other related costs incurred to date	4	4
Advisor Services [Member] | Facility Exit Costs [Member] | Depreciation and amortization [Member]
Restructuring Cost and Reserve [Line Items]
Cumulative exit and other related costs incurred to date	1	1
Advisor Services [Member] | Facility Exit Costs [Member] | Professional services [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		0
Cumulative exit and other related costs incurred to date	0	0
Advisor Services [Member] | Facility Exit Costs [Member] | Other [Member]
Restructuring Cost and Reserve [Line Items]
Exit and other related costs incurred in period		0
Cumulative exit and other related costs incurred to date	$ 0	$ 0