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, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	$ 176	$ 163
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	171	34
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	347	197
Debt Securities, Available-for-sale, Unrealized Loss Position	13,284	4,837
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	10,644	4,068
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	2,640	769
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	156	83
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	104	19
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	260	102
Debt Securities, Available-for-sale, Unrealized Loss Position	12,500	4,202
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	10,045	3,546
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	2,455	656
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	86	29
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	51	5
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	137	34
Debt Securities, Available-for-sale, Unrealized Loss Position	5,081	1,000
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	4,135	930
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	946	70
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	1	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	1	0
Debt Securities, Available-for-sale, Unrealized Loss Position	20	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	20	0
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	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	3	2
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	4	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	7	2
Debt Securities, Available-for-sale, Unrealized Loss Position	234	294
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	132	294
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	102	0
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	22	17
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	6	11
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	28	28
Debt Securities, Available-for-sale, Unrealized Loss Position	2,336	1,666
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,747	1,096
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	589	570
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	2	6
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	2	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	4	6
Debt Securities, Available-for-sale, Unrealized Loss Position	187	160
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	152	160
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	35	0
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	6	1
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	2	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	8	1
Debt Securities, Available-for-sale, Unrealized Loss Position	1,544	27
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	1,513	27
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	31	0
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	3	1
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	2	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	5	4
Debt Securities, Available-for-sale, Unrealized Loss Position	137	82
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	109	66
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	28	16
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	33	27
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	37	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	70	27
Debt Securities, Available-for-sale, Unrealized Loss Position	2,961	973
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	2,237	973
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	724	0
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	20	80
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	67	15
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	87	95
Debt Securities, Available-for-sale, Unrealized Loss Position	784	635
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	599	522
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	185	113
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	13	49
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	44	11
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	57	60
Debt Securities, Available-for-sale, Unrealized Loss Position	560	456
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	463	375
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	97	81
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	0	13
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	13	1
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	13	14
Debt Securities, Available-for-sale, Unrealized Loss Position	13	24
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0	20
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	13	4
External Credit Rating, Non 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	0	15
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	0	15
Debt Securities, Available-for-sale, Unrealized Loss Position	0	91
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	0	91
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	0	0
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	7	3
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	10	3
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses	17	6
Debt Securities, Available-for-sale, Unrealized Loss Position	211	64
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months	136	36
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer	$ 75	$ 28