Accumulated Other Comprehensive Loss (Reconciliation Of The Components Of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in net unrealized gains/losses on investments	$ (2,260)	$ (457)	$ 428
Change in net unrealized gains/losses on cash flow hedges	10	11	12
Change in net periodic pension and postretirement costs	(70)	123	(1)
Foreign currency translation adjustments	(13)	(9)	7
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning	(178)	150	(296)
Other Comprehensive Income (Loss), Net of Tax	(2,336)	(330)	446
Other comprehensive loss attributable to noncontrolling interests	11	2	0
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending	(2,503)	(178)	150
Net gain (loss) realized in other comprehensive loss, tax (expense) benefit	809	110	(154)
Other Comprehensive Income (Loss), Tax Benefit (Expense), Portion Attributable to Noncontrolling Interest	(3)	1	0
Net unrealized investment gains
AOCI, Debt Securities, Beginning Balance	492	949	521
Change in net unrealized gains/losses on investments, before reclassification	(2,614)	(357)	478
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax	354	(100)	(50)
Change in net unrealized gains/losses on investments	(2,260)	(457)	428
AOCI, Debt Securities, Ending Balance	(1,768)	492	949
Net holding gain (loss) on investment securities arising during the period, tax (expense) benefit	926	121	(160)
Reclassification adjustment for net realized loss (gain) on investment securities, tax (benefit) expense	94	(27)	13
Net cash flow hedges
AOCI, Cash Flow Hedges, Beginning Balance	(239)	(250)	(262)
Change in net unrealized gains/losses on cash flow hedges	10	11	12
AOCI, Cash Flow Hedges, Ending Balance	(229)	(239)	(250)
Cash flow hedges, holding gain (loss), tax (expense) benefit	(6)	(3)	(3)
Pension and other postretirement benefits
AOCI, Defined Benefit Plan, Beginning Balance	(429)	(552)	(551)
Change in net periodic pension and postretirement costs	(70)	123	(1)
AOCI, Defined Benefit Plan, Ending Balance	(499)	(429)	(552)
Other Net Change In Unrecognized Periodic Benefit Costs For Defined Benefit Pension And Postretirement Benefit Plans Tax Benefit (Expense)	(23)	(36)	(2)
Foreign currency translation adjustment
AOCI, Foreign Currency Translation Adjustment, Beginning Balance	(4)	5	(2)
Foreign currency translation adjustments	(13)	(9)	7
AOCI, Foreign Currency Translation Adjustment, Ending Balance	(17)	(4)	5
Foreign currency translation adjustment, tax (expense) benefit	6	2	(2)
Non-credit components of impairments on investments
AOCI, Non-credit component of impairments on investments, Beginning Balance	0	(2)	(2)
Change in non-credit component of impairment losses on investments, net of tax	(3)	2	0
AOCI, Non-credit component of impairments on investments, Ending Balance	(3)	0	(2)
Non-credit component of other-than-temporary impairments on investments, tax (expense) benefit	$ 0	$ (1)	$ 0