Schedule I - Condensed Financial Information Of Parent Other Income (Expense), Net (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Other Nonoperating Income (Expense) [Line Items]
Defined Benefit Plan, Non-service Cost or Income Components	$ 70	$ 44	$ 56
Donations	33	8	16
Other Nonoperating Income (Expense)	102	86	101
Parent Company
Other Nonoperating Income (Expense) [Line Items]
Defined Benefit Plan, Non-service Cost or Income Components	2	2	5
Donations	(13)	0	(5)
Other Expenses	(1)	0	0
Other Nonoperating Income (Expense)	$ (12)	$ 2	$ 0