Other Income - Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Income and Expenses [Abstract]
Cost associated with early redemption of long-term debt included in miscellaneous expense	$ 10
Net Periodic Pension and Post-retirement Benefit Credit	43	$ 38	$ 32
Interest Income	48	32	13
Miscellaneous (Expense) Income	(3)	4	8
Total Other Income - Net	$ 88	$ 74	$ 53