Summary Of Changes In Accumulated Other Comprehensive Income (Loss) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Accumulated other comprehensive income [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ 43	$ (250)	$ (139)
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	84	(37)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax	10	1
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	2	0
Other Comprehensive Income (Loss), Tax	96	(36)
Other Comprehensive Income (Loss), Net of Tax	293	(111)	(17)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	287	(116)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	6	5
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount	0	(2)	(47)
Effect of Change in Tax Rate, OCI	0	0	25
Income Tax Expense (Benefit)	237	259	344
Net earnings applicable to common shareholders	782	850	550
Reclassification of amortization of net actuarial gains losses pension and post retirement from AOCI, gross	2	3	7
Reclassification of pension and postretirement from accumulated other comprehensive income, tax	1	1	3
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated other comprehensive income [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	29	(228)	(114)
Other Comprehensive Income (Loss), Net of Tax	257	(114)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	257	(114)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	0
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated other comprehensive income [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	28	(1)	(3)
Other Comprehensive Income (Loss), Net of Tax	29	2
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	24	(1)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	5	3
Net earnings applicable to common shareholders	(5)	(3)	2
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated other comprehensive income [Line Items]
Accumulated Other Comprehensive Income (Loss), Net of Tax	(14)	(21)	(22)
Other Comprehensive Income (Loss), Net of Tax	7	1
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	6	(1)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1	2	4
Interest Rate Contract [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated other comprehensive income [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	(6)	(4)	4
Income Tax Expense (Benefit)	$ (1)	$ (1)	$ 2