Acquisition and Restructuring (Details) Customer_Account in Millions, $ in Millions				3 Months Ended	12 Months Ended
	Dec. 09, 2019 USD ($)	Nov. 06, 2018 USD ($) Customer_Account	Apr. 09, 2018 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Business Acquisition [Line Items]
Payments to acquire businesses, net of cash acquired					$ 29	$ 150	$ 0
Restructuring and Related Activities [Abstract]
Restructuring activities				$ 21	21	4	12
Acquisition-related costs					2	3	3
Total restructuring and acquisition-related activities					23	$ 7	$ 15
Business Exit Costs					9
Severance Costs					12
Gradifi [Member]
Business Acquisition [Line Items]
Payments to acquire businesses	$ 30
Fair value of net assets acquired	5
Goodwill acquired during period	25				25
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract]
Other intangibles	3			$ 3	$ 3
Other	5
Total assets acquired	8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract]
Other liabilities	3
Total Liabilities Assumed	3
Fair value of net assets acquired	5
Gradifi [Member] | Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value	$ 3
Estimated Useful Life (In Years)	6 years
Capital One [Member]
Business Acquisition [Line Items]
Number of brokerage accounts acquired | Customer_Account		1,000,000
Payments to acquire businesses, net of cash acquired		$ 109
Capital One [Member] | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value		$ 114
Estimated Useful Life (In Years)		11 years
Trust Company Of America [Member]
Business Acquisition [Line Items]
Goodwill acquired during period			$ 115
Payments to acquire businesses, net of cash acquired			275
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value			140
Trust Company Of America [Member] | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value			$ 119
Estimated Useful Life (In Years)			22 years
Trust Company Of America [Member] | Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value			$ 20
Estimated Useful Life (In Years)			5 years
Trust Company Of America [Member] | Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Estimated Fair Value			$ 1
Estimated Useful Life (In Years)			2 years