Restructuring - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) position	Dec. 31, 2019 USD ($) position	Dec. 31, 2018 USD ($)
2020 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Workforce reduction, positions | position	830
Restructuring reserve	$ 7
Initial Charge Recorded	65
2019 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Workforce reduction, positions | position		300
Restructuring reserve	13	$ 7
Initial Charge Recorded	$ 25	25
2018 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Restructuring reserve		$ 3
Initial Charge Recorded			$ 25