Fair Value Information (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Redeemable Preferred Securities Of Subsidiaries Fair Value Disclosure	$ 28	$ 28
Fair Value, Measurements, Recurring | Net Asset Value or Its Equivalent
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Cash Surrender Value, Fair Value Disclosure	73	73
Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivatives Assets	41	44
Derivatives Liability	$ 60	$ 92