Claim and Claim Adjustment Expense Reserves and Future Policy Benefit Reserves (International - Excluding Hardy - Net Incurred Claims and Allocated Claim Adjustment Expenses) (Details) - Excluding Hardy - International $ in Millions	Dec. 31, 2022 USD ($) claim	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 3,309
IBNR	901
2013
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	235	$ 234	$ 231	$ 235	$ 243	$ 250	$ 255	$ 274	$ 281	$ 279
IBNR	$ 11
Cumulative Number of Claims | claim	23,971
2014
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 279	273	282	281	264	271	282	283	$ 268
IBNR	$ 13
Cumulative Number of Claims | claim	24,962
2015
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 277	277	275	273	278	294	295	$ 280
IBNR	$ 22
Cumulative Number of Claims | claim	23,372
2016
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 283	281	268	277	279	292	$ 275
IBNR	$ 29
Cumulative Number of Claims | claim	17,813
2017
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 348	359	364	371	351	$ 290
IBNR	$ 57
Cumulative Number of Claims | claim	18,498
2018
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 390	378	379	374	$ 357
IBNR	$ 67
Cumulative Number of Claims | claim	20,849
2019
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 348	341	344	$ 331
IBNR	$ 69
Cumulative Number of Claims | claim	18,354
2020
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 350	360	$ 368
IBNR	$ 138
Cumulative Number of Claims | claim	14,952
2021
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 385	$ 396
IBNR	$ 201
Cumulative Number of Claims | claim	13,580
2022
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 414
IBNR	$ 294
Cumulative Number of Claims | claim	8,320