Claim and Claim Adjustment Expense Reserves and Future Policy Benefit Reserves (International - Hardy - Net Incurred Claims and Allocated Claim Adjustment Expenses) (Details) - 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 ($)	Dec. 31, 2013 USD ($)
Hardy
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 2,016
IBNR	349
Hardy | 2013
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	144	$ 141	$ 142	$ 142	$ 141	$ 138	$ 137	$ 136	$ 143	$ 127
IBNR	$ 3
Cumulative Number of Claims | claim	7,904,000,000
Hardy | 2014
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 164	165	167	169	168	167	173	180	182
IBNR	$ (4)
Cumulative Number of Claims | claim	8,530,000,000
Hardy | 2015
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 177	175	174	172	174	174	175	186
IBNR	$ (2)
Cumulative Number of Claims | claim	9,722,000,000
Hardy | 2016
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 216	215	222	220	231	240	224
IBNR	$ 3
Cumulative Number of Claims | claim	10,834,000,000
Hardy | 2017
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 249	249	242	241	248	240
IBNR	$ 5
Cumulative Number of Claims | claim	13,204,000,000
Hardy | 2018
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 303	303	298	295	264
IBNR	$ 26
Cumulative Number of Claims | claim	15,185,000,000
Hardy | 2019
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 221	214	219	216
IBNR	$ 37
Cumulative Number of Claims | claim	11,374,000,000
Hardy | 2020
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 191	197	206
IBNR	$ 62
Cumulative Number of Claims | claim	6,699,000,000
Hardy | 2021
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 164	174
IBNR	$ 83
Cumulative Number of Claims | claim	3,384,000,000
Hardy | 2022
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 187
IBNR	$ 136
Cumulative Number of Claims | claim	1,279,000,000
Excluding Hardy
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
Excluding Hardy | 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
Excluding Hardy | 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
Excluding Hardy | 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
Excluding Hardy | 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
Excluding Hardy | 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
Excluding Hardy | 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
Excluding Hardy | 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
Excluding Hardy | 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
Excluding Hardy | 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
Excluding Hardy | 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