Schedule I - Condensed Financial Information Of Parent Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Deferred Federal Income Tax Expense (Benefit)	$ 220	$ 511	$ 299
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability	13
Tax Cuts and Jobs Act [Member]
Income Taxes [Line Items]
Deferred Federal Income Tax Expense (Benefit)		154
Parent Company
Income Taxes [Line Items]
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability	$ 5
Parent Company | Tax Cuts and Jobs Act [Member]
Income Taxes [Line Items]
Deferred Federal Income Tax Expense (Benefit)		$ 110