Leases (Assets and Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
ROU assets, net of amortization	$ 195	$ 213
Lease liabilities	222	240
ROU assets, net of amortization	4	4
Finance lease obligations	$ 4	$ 4
Weighted average remaining lease term, operating leases (in years)	8 years 6 months	8 years 10 months 24 days
Weighted average remaining lease term, finance leases (in years)	18 years 3 months 18 days	19 years 2 months 12 days
Weighted average discount rate, operating leases	2.80%	2.90%
Weighted average discount rate, finance leases	3.10%	3.10%