Claim, Claim Adjustment Expense and Future Policy Benefit Reserves (International - Hardy - Net Incurred Claims and Allocated Claim Adjustment Expenses) (Details) - International $ in Millions	Dec. 31, 2021 USD ($) claim	Dec. 31, 2020 USD ($)	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 ($)	Dec. 31, 2012 USD ($)
Hardy
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 2,008
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented	529
IBNR	297
Hardy | 2012
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Net Claim and Allocated Claim Adjustment Expense Reserves at Acquisition										$ 34
Incurred claims and allocated claim adjustment expense, net	114	$ 113	$ 115	$ 116	$ 114	$ 113	$ 120	$ 112	$ 105	71
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented										105
IBNR	$ (3)
Cumulative Number of Claims | claim	7,045,000,000
Hardy | 2013
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 144	146	146	145	142	140	139	147	132
IBNR	$ 7
Cumulative Number of Claims | claim	7,893,000,000
Hardy | 2014
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 169	172	173	172	171	178	184	186
IBNR	$ (6)
Cumulative Number of Claims | claim	8,493,000,000
Hardy | 2015
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 181	180	178	180	179	181	191
IBNR	$ (1)
Cumulative Number of Claims | claim	9,669,000,000
Hardy | 2016
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 222	228	226	238	249	231
IBNR	$ (1)
Cumulative Number of Claims | claim	10,746,000,000
Hardy | 2017
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 253	246	244	256	246
IBNR	$ 8
Cumulative Number of Claims | claim	13,029,000,000
Hardy | 2018
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 316	310	306	275
IBNR	$ 36
Cumulative Number of Claims | claim	14,868,000,000
Hardy | 2019
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 223	228	224
IBNR	$ 42
Cumulative Number of Claims | claim	10,891,000,000
Hardy | 2020
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 205	215
IBNR	$ 87
Cumulative Number of Claims | claim	5,963,000,000
Hardy | 2021
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 181
IBNR	$ 128
Cumulative Number of Claims | claim	2,244,000,000
Excluding Hardy
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 3,371
Net liability for unpaid claim and allocated claim adjustment expenses for the accident years presented	1,318
IBNR	845
Excluding Hardy | 2012
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	250	236	241	247	254	261	262	269	285	$ 278
IBNR	$ 16
Cumulative Number of Claims | claim	24,998
Excluding Hardy | 2013
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 251	247	251	260	269	273	293	301	$ 285
IBNR	$ 12
Cumulative Number of Claims | claim	23,967
Excluding Hardy | 2014
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 294	301	300	283	291	303	303	$ 288
IBNR	$ 16
Cumulative Number of Claims | claim	24,946
Excluding Hardy | 2015
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 297	294	292	298	316	317	$ 301
IBNR	$ 27
Cumulative Number of Claims | claim	23,357
Excluding Hardy | 2016
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 302	287	297	300	315	$ 296
IBNR	$ 37
Cumulative Number of Claims | claim	17,776
Excluding Hardy | 2017
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 388	393	401	378	$ 312
IBNR	$ 84
Cumulative Number of Claims | claim	18,470
Excluding Hardy | 2018
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 406	407	402	$ 384
IBNR	$ 81
Cumulative Number of Claims | claim	20,726
Excluding Hardy | 2019
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 368	371	$ 357
IBNR	$ 91
Cumulative Number of Claims | claim	17,974
Excluding Hardy | 2020
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 389	$ 398
IBNR	$ 184
Cumulative Number of Claims | claim	13,909
Excluding Hardy | 2021
Short-duration Insurance Contracts, Net Incurred Claim and Claim Adjustment Expenses [Line Items]
Incurred claims and allocated claim adjustment expense, net	$ 426
IBNR	$ 297
Cumulative Number of Claims | claim	10,401