Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Other intangible assets:
Estimated Fair Value	$ 78	$ 78
Accumulated Amortization	21	17
Net Carrying Amount	57	61
Customer relationships
Other intangible assets:
Estimated Fair Value	42	42
Accumulated Amortization	10	8
Net Carrying Amount	32	34
Other
Other intangible assets:
Estimated Fair Value	36	36
Accumulated Amortization	11	9
Net Carrying Amount	$ 25	$ 27