Investments (Fair Value and Losses by Investment Category and Length of Time in a Loss Position) (Details) - Fixed Maturities [Member] - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	$ 3,693	$ 176
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	3,615	171
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	7,308	347
Debt Securities, Available-for-sale, Unrealized Loss Position	44,546	13,284
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	31,631	10,644
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	12,915	2,640
External Credit Rating, Investment Grade [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	3,598	156
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	3,485	104
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	7,083	260
Debt Securities, Available-for-sale, Unrealized Loss Position	43,181	12,500
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	30,773	10,045
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	12,408	2,455
External Credit Rating, Investment Grade [Member] | Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	2,756	86
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	2,225	51
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	4,981	137
Debt Securities, Available-for-sale, Unrealized Loss Position	28,707	5,081
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	21,867	4,135
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	6,840	946
External Credit Rating, Investment Grade [Member] | Canadian Provincial Governments [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	42	1
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	23	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	65	1
Debt Securities, Available-for-sale, Unrealized Loss Position	625	20
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	554	20
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	71	0
External Credit Rating, Investment Grade [Member] | Residential Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	62	3
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	53	4
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	115	7
Debt Securities, Available-for-sale, Unrealized Loss Position	845	234
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	664	132
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	181	102
External Credit Rating, Investment Grade [Member] | Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	153	22
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	269	6
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	422	28
Debt Securities, Available-for-sale, Unrealized Loss Position	3,527	2,336
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,596	1,747
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	1,931	589
External Credit Rating, Investment Grade [Member] | Commercial Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	144	2
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	65	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	209	4
Debt Securities, Available-for-sale, Unrealized Loss Position	1,595	187
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,314	152
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	281	35
External Credit Rating, Investment Grade [Member] | US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	64	6
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	148	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	212	8
Debt Securities, Available-for-sale, Unrealized Loss Position	1,455	1,544
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,202	1,513
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	253	31
External Credit Rating, Investment Grade [Member] | US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	124	3
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	50	2
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	174	5
Debt Securities, Available-for-sale, Unrealized Loss Position	950	137
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	819	109
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	131	28
External Credit Rating, Investment Grade [Member] | Debt Security, Government, Non-US [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	253	33
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	652	37
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	905	70
Debt Securities, Available-for-sale, Unrealized Loss Position	5,477	2,961
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	2,757	2,237
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	2,720	724
External Credit Rating, Non Investment Grade [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	95	20
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	130	67
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	225	87
Debt Securities, Available-for-sale, Unrealized Loss Position	1,365	784
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	858	599
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	507	185
External Credit Rating, Non Investment Grade [Member] | Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	87	13
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	61	44
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	148	57
Debt Securities, Available-for-sale, Unrealized Loss Position	1,072	560
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	767	463
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	305	97
External Credit Rating, Non Investment Grade [Member] | Asset-backed Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	6	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	9	13
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	15	13
Debt Securities, Available-for-sale, Unrealized Loss Position	90	13
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	52	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	38	13
External Credit Rating, Non Investment Grade [Member] | Debt Security, Government, Non-US [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	2	7
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	60	10
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	62	17
Debt Securities, Available-for-sale, Unrealized Loss Position	203	211
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	39	136
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 164	$ 75