Leases (Maturity Analysis) (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Maturities of operating leases (ASC 842):
2020	$ 41
2021	33
2022	22
2023	19
2024	15
Thereafter	52
Total undiscounted lease liability	182
Imputed interest	(29)
Total discounted lease liability	$ 153
Maturities of operating leases (ASC 840):
2019		$ 38
2020		28
2021		14
2022		6
2023		5
Thereafter		4
Total minimum payments required		$ 95

Amount of lessee's undiscounted obligation for lease payments for operating lease.

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