Retirement Plans - Schedule of Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Amortization of actuarial loss	$ 1	$ 1	$ 0
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	4	4	5
Interest cost	1	1	2
Expected return on plan assets	(2)	(2)	(2)
Net periodic benefit cost	$ 4	$ 4	$ 4