Accounting Changes and Error Corrections (DAC) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021	Jan. 01, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	$ 4,289	$ 4,004	$ 4,289	$ 4,004	$ 4,128
Deferred Policy Acquisition Costs, Amortization Expense	(348)	(341)	(1,028)	(1,021)
Life Insurance Product Line [Member] | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	2,160	2,047	2,160	2,047	2,087	$ 1,947
Deferred Policy Acquisition Cost, Capitalization			183	208
Deferred Policy Acquisition Costs, Amortization Expense			(111)	(108)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)			1	0
Life Insurance Product Line [Member] | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	169	166	169	166	171	191
Deferred Policy Acquisition Cost, Capitalization			7	5
Deferred Policy Acquisition Costs, Amortization Expense			(9)	(14)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)			0	(16)
Life Insurance Product Line [Member] | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	331	262	331	262	294	270
Deferred Policy Acquisition Cost, Capitalization			75	57
Deferred Policy Acquisition Costs, Amortization Expense			(28)	(25)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)			(10)	(40)
Life Insurance Product Line [Member] | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	1,069	1,012	1,069	1,012	1,043	1,056
Deferred Policy Acquisition Cost, Capitalization			94	66
Deferred Policy Acquisition Costs, Amortization Expense			(44)	(53)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)			(24)	(57)
Insurance, Other | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	309	355	309	355	341	312
Deferred Policy Acquisition Cost, Capitalization			0	85
Deferred Policy Acquisition Costs, Amortization Expense			(32)	(42)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)			0	0
Insurance, Other | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	0	0	0	0	0	0
Deferred Policy Acquisition Cost, Capitalization			0	0
Deferred Policy Acquisition Costs, Amortization Expense			0	0
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)			0	0
Insurance, Other | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	0	0	0	0	0	0
Deferred Policy Acquisition Cost, Capitalization			0	0
Deferred Policy Acquisition Costs, Amortization Expense			0	0
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)			0	0
Insurance, Other | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs	$ 247	$ 158	247	158	188	81
Deferred Policy Acquisition Cost, Capitalization			89	92
Deferred Policy Acquisition Costs, Amortization Expense			(24)	(13)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)			$ (6)	$ (2)
Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs					4,128	3,860
Deferred Policy Acquisition Costs, Amortization Expense					(1,344)	(1,325)
Accounting Standards Update 2018-12 | Life Insurance Product Line [Member] | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs					2,087	1,947
Deferred Policy Acquisition Cost, Capitalization					284	254
Deferred Policy Acquisition Costs, Amortization Expense					(144)	(123)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)					0	0
Accounting Standards Update 2018-12 | Life Insurance Product Line [Member] | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs					171	191
Deferred Policy Acquisition Cost, Capitalization					10	8
Deferred Policy Acquisition Costs, Amortization Expense					(17)	(13)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)					(13)	1
Accounting Standards Update 2018-12 | Life Insurance Product Line [Member] | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs					294	270
Deferred Policy Acquisition Cost, Capitalization					83	42
Deferred Policy Acquisition Costs, Amortization Expense					(38)	(24)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)					(21)	(12)
Accounting Standards Update 2018-12 | Life Insurance Product Line [Member] | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs					1,043	1,056
Deferred Policy Acquisition Cost, Capitalization					86	83
Deferred Policy Acquisition Costs, Amortization Expense					(67)	(55)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)					(32)	(18)
Accounting Standards Update 2018-12 | Insurance, Other | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs					341	312	$ 368
Deferred Policy Acquisition Cost, Capitalization					87	8
Deferred Policy Acquisition Costs, Amortization Expense					(58)	(64)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)					0	0
Accounting Standards Update 2018-12 | Insurance, Other | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs					0	0	0
Deferred Policy Acquisition Cost, Capitalization					0	0
Deferred Policy Acquisition Costs, Amortization Expense					0	0
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)					0	0
Accounting Standards Update 2018-12 | Insurance, Other | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs					0	0	0
Deferred Policy Acquisition Cost, Capitalization					0	0
Deferred Policy Acquisition Costs, Amortization Expense					0	0
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)					0	0
Accounting Standards Update 2018-12 | Insurance, Other | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs					188	81	$ 41
Deferred Policy Acquisition Cost, Capitalization					121	49
Deferred Policy Acquisition Costs, Amortization Expense					(13)	(8)
Deferred Policy Acquisition Costs, Foreign Currency Translation Gain (Loss)					$ (1)	$ (1)
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjustment | Life Insurance Product Line [Member] | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								$ 0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjustment | Life Insurance Product Line [Member] | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjustment | Life Insurance Product Line [Member] | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjustment | Life Insurance Product Line [Member] | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjustment | Insurance, Other | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								114
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjustment | Insurance, Other | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjustment | Insurance, Other | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjustment | Insurance, Other | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjusted Balance | Life Insurance Product Line [Member] | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								1,816
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjusted Balance | Life Insurance Product Line [Member] | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								195
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjusted Balance | Life Insurance Product Line [Member] | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								264
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjusted Balance | Life Insurance Product Line [Member] | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								1,046
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjusted Balance | Insurance, Other | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								368
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjusted Balance | Insurance, Other | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjusted Balance | Insurance, Other | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Adjusted Balance | Insurance, Other | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								41
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Original Balance | Life Insurance Product Line [Member] | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								1,816
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Original Balance | Life Insurance Product Line [Member] | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								195
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Original Balance | Life Insurance Product Line [Member] | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								264
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Original Balance | Life Insurance Product Line [Member] | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								1,046
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Original Balance | Insurance, Other | Americas [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								254
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Original Balance | Insurance, Other | CANADA | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Original Balance | Insurance, Other | EMEA [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								0
Accounting Standards Update 2018-12 | Cumulative Effect, Period of Adoption, Original Balance | Insurance, Other | Asia Pacific [Member] | Other Segments
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred policy acquisition costs								$ 41