Retirement Plans - Schedule Of Components Of Net Periodic Benefit Cost (Details) - Pension Plan - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Components of net periodic benefit cost
Interest cost	$ 4	$ 6	$ 8	$ 12
Expected return on plan assets	(4)	(6)	(8)	(12)
Actuarial (gain) loss	2	3	4	6
Other			2	0
Net periodic benefit cost	$ 2	$ 3	$ 6	$ 6