Restructuring, Repositioning, and Efficiency (Details) - 2019 Business Optimization $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	$ 40
Personnel expense
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	11
Legal and professional fees
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	16
Net occupancy expense
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	1
Other
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	$ 12