Financing Activities - Equity Securities (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Oct. 31, 2021	Sep. 30, 2021	Sep. 30, 2021	Jul. 01, 2021	Feb. 28, 2018
Securities Financing Transaction [Line Items]
Common Stock Aggregate Sales Price					$ 1,000
Common stock issued			0
Stock Repurchase Program, Authorized Amount				$ 3,000
Treasury stock acquired		9,600,000	9,600,000
Maximum Percentage Paid To Selling Agents			2.00%
Treasury Stock, Value, Acquired		$ 282	$ 282
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 1,000	$ 1,000
Subsequent Event [Member]
Securities Financing Transaction [Line Items]
Treasury stock acquired	9,400,000
Treasury Stock, Value, Acquired	$ 269