Restructuring - Narrative (Details) - 2019 Restructuring - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Total expected pre-tax restructuring charges	$ 190
Forecast
Restructuring Cost and Reserve [Line Items]
Total expected pre-tax restructuring charges		$ 50
Severance and employee-related costs
Restructuring Cost and Reserve [Line Items]
Percentage of aggregate charge	60.00%
Facilities and related costs
Restructuring Cost and Reserve [Line Items]
Percentage of aggregate charge	20.00%
Other costs
Restructuring Cost and Reserve [Line Items]
Percentage of aggregate charge	20.00%