Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		15 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2020
Income Tax [Line Items]
Payroll tax deferral from CARES Act through December 2020					$ 73
Favorable net discrete items, percentage impact	6.00%		3.00%
Payroll Taxes Paid			$ 37
Unfavorable discrete items, percentage impact	1.00%	1.00%	2.00%
Income taxes	$ 136	$ 169	$ 416	$ 280
Effective income tax rate	17.00%	23.00%	21.00%	22.00%