Equity (Components of Other Comprehensive Income) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss), before Reclassification and Tax		$ 85	$ 43	$ 113
Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax		(24)	3	(10)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax		61	46	103
Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Foreign Currency Swap, Before Reclassification and Tax		(2)	(29)	(33)
Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Foreign Currency Swap Tax		1	6	7
Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Foreign Currency Swap Net Of Tax		(1)	(23)	(26)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax		83	14	80
Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax		(23)	9	(3)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax		60	23	77
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, before Tax	[1]	(2,093)	2,812	3,208
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, Tax	[1]	471	(614)	(698)
Other Comprehensive Income (Loss), Securities, Available-for-Sale, Unrealized Holding Gain (Loss) Arising During Period, after Tax	[1]	(1,622)	2,198	2,510
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, before Tax	[1]	226	(8)	84
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Tax	[1]	(49)	(1)	(17)
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Net of Tax	[1]	177	(9)	67
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, before Reclassification Adjustments and Tax	[1]	(2,319)	2,820	3,124
Other Comprehensive Income (Loss), Available-for-sale Securities, before Reclassification Adjustments, Tax	[1]	520	(613)	(681)
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax	[1]	(1,799)	2,207	2,443
Other than Temporary Impairment Loss, Investments, Portion in Other Comprehensive Loss, before Tax, Portion Attributable to Parent, Available-for-sale Securities		0	(8)	0
Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, Tax, Portion Attributable to Parent, Available-for-sale Securities		0	2	0
Change in other-than-temporary impairment losses on fixed maturity securities		0	(6)	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax		2	(1)	(1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax		0	0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax		2	(1)	(1)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax		27	(2)	(23)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax		(7)	1	5
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax		20	(1)	(18)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax		29	(3)	(24)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax		(7)	1	5
Defined benefit pension and postretirement plan adjustments		22	(2)	(19)
Other Comprehensive Income (Loss), before Tax		(2,207)	2,823	3,180
Other Comprehensive Income (Loss), Tax		490	(601)	(679)
Other Comprehensive Income (Loss), Net of Tax		$ (1,717)	$ 2,222	$ 2,501

[1] Includes cash flow hedges. See Note 5 for additional information on cash flow hedges.