Restructuring, Repositioning, and Efficiency (Details) - 2019 Business Optimization - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	$ 40	$ 18,668	$ 3	$ 30,820
Employee compensation, incentives and benefits
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	32	2,557	89	9,062
Professional fees
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	7	4,242	14	8,537
Occupancy
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	0	72	2	889
Other
Restructuring Cost and Reserve [Line Items]
Total restructuring, repositioning, and efficiency charges	$ 1	$ 11,797	$ (102)	$ 12,332