Fair Value Information Narrative (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Derivative Assets	$ 34	$ 30
Derivative Liability	44	18
Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Redeemable Preferred Securities Of Subsidiaries Fair Value Disclosure	29	64
Net Asset Value or Its Equivalent
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Company-owned life insurance (COLI)	$ 76	$ 64