Derivative Financial Instruments - Exposure to Credit Loss on Call Options Held (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Fair Value	$ 756	$ 546
Not Designated as Hedging Instrument \| Call options
Derivatives, Fair Value [Line Items]
Notional Amount	28,522	23,297
Fair Value	404	244
Collateral	381	219
Net Credit Risk	40	33
Not Designated as Hedging Instrument \| Call options \| Merrill Lynch
Derivatives, Fair Value [Line Items]
Notional Amount	4,131	3,563
Fair Value	47	23
Collateral	8	0
Net Credit Risk	39	23
Not Designated as Hedging Instrument \| Call options \| Morgan Stanley
Derivatives, Fair Value [Line Items]
Notional Amount	2,865	1,699
Fair Value	32	14
Collateral	38	19
Net Credit Risk	0	0
Not Designated as Hedging Instrument \| Call options \| Barclay's Bank
Derivatives, Fair Value [Line Items]
Notional Amount	6,809	6,049
Fair Value	73	65
Collateral	81	59
Net Credit Risk	0	6
Not Designated as Hedging Instrument \| Call options \| Canadian Imperial Bank of Commerce
Derivatives, Fair Value [Line Items]
Notional Amount	6,903	5,169
Fair Value	92	68
Collateral	94	64
Net Credit Risk	0	4
Not Designated as Hedging Instrument \| Call options \| Wells Fargo
Derivatives, Fair Value [Line Items]
Notional Amount	1,300	1,361
Fair Value	37	17
Collateral	38	17
Net Credit Risk	0	0
Not Designated as Hedging Instrument \| Call options \| Goldman Sachs
Derivatives, Fair Value [Line Items]
Notional Amount	1,520	1,133
Fair Value	16	9
Collateral	16	10
Net Credit Risk	0	0
Not Designated as Hedging Instrument \| Call options \| Credit Suisse
Derivatives, Fair Value [Line Items]
Notional Amount	198	1,039
Fair Value	6	5
Collateral	6	5
Net Credit Risk	0	0
Not Designated as Hedging Instrument \| Call options \| Truist
Derivatives, Fair Value [Line Items]
Notional Amount	2,853	2,489
Fair Value	78	35
Collateral	77	36
Net Credit Risk	1	0
Not Designated as Hedging Instrument \| Call options \| Citibank
Derivatives, Fair Value [Line Items]
Notional Amount	1,400	795
Fair Value	11	8
Collateral	11	9
Net Credit Risk	0	$ 0
Not Designated as Hedging Instrument \| Call options \| JP Morgan
Derivatives, Fair Value [Line Items]
Notional Amount	543
Fair Value	12
Collateral	12
Net Credit Risk	$ 0

Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

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