Leasing (Lease, Cost) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Leases [Abstract]
Operating lease expense	$ 11	$ 12	$ 24	$ 23
Variable lease expense	2	2	4	4
Total lease expense, net	$ 13	$ 14	$ 28	$ 27