Income Taxes Uncertain tax positions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Unrecognized Tax Benefits	$ 13	$ 6	$ 9	$ 11
Tax positions taken in current year	1	1	1
Tax positions taken in prior years	6	0	0
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	0	4	$ 3
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	13
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	2	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Paid	$ 0	$ 0