Derivatives and Hedge Accounting - Notional amounts and fair values of derivative instruments (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Gross Derivative Assets
Notional Amount	$ 148,816	$ 133,721
Fair Value	6,499	6,049
Counterparty netting	(3,985)	(3,895)
Cash Collateral	(2,141)	(1,640)
Total derivative assets	373	514
Gross Derivative Liabilities
Notional Amount	68,842	56,805
Fair Value	6,716	6,043
Counterparty netting	(3,985)	(3,895)
Cash Collateral	(2,472)	(1,917)
Total derivative liabilities on consolidated balance sheet	259	231
Bifurcated embedded derivatives assets, fair value	3,400	2,200
Bifurcated embedded derivative liabilities, fair value	6,400	5,400
Derivatives designated as hedging instruments | Interest rate contracts
Gross Derivative Assets
Notional Amount	179	251
Fair Value	191	355
Gross Derivative Liabilities
Notional Amount	3,104	1,688
Fair Value	78	66
Derivatives designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	6,115	4,543
Fair Value	525	642
Gross Derivative Liabilities
Notional Amount	1,630	4,899
Fair Value	235	317
Derivatives not designated as hedging instruments | Interest rate contracts
Gross Derivative Assets
Notional Amount	36,494	39,833
Fair Value	3,057	3,367
Gross Derivative Liabilities
Notional Amount	35,271	34,128
Fair Value	5,096	4,772
Derivatives not designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	16,539	8,626
Fair Value	1,255	1,202
Gross Derivative Liabilities
Notional Amount	5,139	10,397
Fair Value	416	821
Derivatives not designated as hedging instruments | Equity contracts
Gross Derivative Assets
Notional Amount	42,372	31,264
Fair Value	1,422	428
Gross Derivative Liabilities
Notional Amount	23,162	4,740
Fair Value	853	26
Derivatives not designated as hedging instruments | Commodity contracts
Gross Derivative Assets
Notional Amount	0	212
Fair Value	0	9
Gross Derivative Liabilities
Notional Amount	0	20
Fair Value	0	0
Derivatives not designated as hedging instruments | Credit contracts
Gross Derivative Assets
Notional Amount	1,806	1,808
Fair Value	33	32
Gross Derivative Liabilities
Notional Amount	536	933
Fair Value	38	41
Derivatives not designated as hedging instruments | Credit contracts | CDS
Gross Derivative Liabilities
Notional Amount	51	79
Fair Value	33	32
Derivatives not designated as hedging instruments | Other contracts
Gross Derivative Assets
Notional Amount	45,311	47,184
Fair Value	16	14
Gross Derivative Liabilities
Notional Amount	0	0
Fair Value	$ 0	$ 0