Derivatives and Hedge Accounting - Notional Amounts and Fair Values of Derivative Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Gross Derivative Assets
Notional Amount	$ 201,538	$ 184,921
Fair Value	7,722	6,595
Counterparty netting	(4,545)	(3,864)
Cash Collateral	(2,601)	(2,220)
Total derivative assets	576	511
Gross Derivative Liabilities
Notional Amount	57,973	69,672
Fair Value	5,272	5,309
Counterparty netting	(4,545)	(3,864)
Cash Collateral	(326)	(1,050)
Total derivative liabilities on consolidated balance sheet	401	395
Bifurcated embedded derivatives assets, fair value	1,400	1,200
Bifurcated embedded derivative liabilities, fair value	8,700	8,000
Derivatives designated as hedging instruments | Interest rate contracts
Gross Derivative Assets
Notional Amount	577	1,863
Fair Value	208	230
Gross Derivative Liabilities
Notional Amount	2,638	752
Fair Value	50	17
Derivatives designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	5,627	3,847
Fair Value	385	416
Gross Derivative Liabilities
Notional Amount	1,932	6,402
Fair Value	204	336
Derivatives not designated as hedging instruments | Interest rate contracts
Gross Derivative Assets
Notional Amount	52,800	42,549
Fair Value	3,276	3,056
Gross Derivative Liabilities
Notional Amount	36,050	42,466
Fair Value	3,329	3,614
Derivatives not designated as hedging instruments | Foreign exchange contracts
Gross Derivative Assets
Notional Amount	14,993	8,803
Fair Value	851	820
Gross Derivative Liabilities
Notional Amount	6,430	9,900
Fair Value	423	558
Derivatives not designated as hedging instruments | Equity contracts
Gross Derivative Assets
Notional Amount	80,551	81,110
Fair Value	2,878	2,019
Gross Derivative Liabilities
Notional Amount	10,368	9,595
Fair Value	1,229	745
Derivatives not designated as hedging instruments | Credit contracts
Gross Derivative Assets
Notional Amount	3,808	2,109
Fair Value	111	41
Gross Derivative Liabilities
Notional Amount	508	509
Fair Value	36	37
Derivatives not designated as hedging instruments | Credit contracts | CDS
Gross Derivative Liabilities
Notional Amount	49	50
Fair Value	33	32
Derivatives not designated as hedging instruments | Other contracts
Gross Derivative Assets
Notional Amount	43,182	44,640
Fair Value	13	13
Gross Derivative Liabilities
Notional Amount	47	48
Fair Value	$ 1	$ 2