Derivative Financial Instruments - Summary of the volume and fair value positions of derivative instruments (Details) $ in Millions	Sep. 30, 2022 USD ($) contract	Dec. 31, 2021 USD ($) contract
Derivatives, Fair Value
Total asset derivatives, notional amount	$ 1,118	$ 1,285
Total liability derivatives, notional amount	744	790
Total derivatives, notional amount	$ 1,862	$ 2,075
Total asset derivatives, number of contracts | contract	47,271	1,355
Total liability derivatives, number of contracts | contract	7,853	37,928
Total derivatives, Number of contracts | contract	55,124	39,283
Net amount on balance sheet	$ 161	$ 76
Net amount on balance sheet	23	9
Total derivatives, fair value, net	184	85
Gross amount	165	77
Liability derivatives, gross asset	60	23
Asset derivatives, gross liability	(4)	(1)
Liability derivatives gross amount	$ (37)	$ (14)
Futures | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	45,626	1,181
Total liability derivatives, number of contracts | contract	2,969	36,668
Net amount on balance sheet	$ 14	$ 1
Net amount on balance sheet	(1)	(2)
Gross amount	14	1
Liability derivatives, gross asset	0	0
Asset derivatives, gross liability	0	0
Liability derivatives gross amount	$ (1)	$ (2)
Options | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	1,309	61
Total liability derivatives, number of contracts | contract	1,210
Net amount on balance sheet	$ 44	$ 5
Net amount on balance sheet	(16)
Gross amount	44	5
Liability derivatives, gross asset	0
Asset derivatives, gross liability	0	$ 0
Liability derivatives gross amount	$ (16)
Futures | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	336	113
Total liability derivatives, number of contracts | contract	3,674	1,260
Net amount on balance sheet	$ 0	$ 0
Net amount on balance sheet	(8)	(1)
Gross amount	0	0
Liability derivatives, gross asset	0	0
Asset derivatives, gross liability	0	0
Liability derivatives gross amount	(8)	(1)
Foreign currency forwards | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, notional amount	39	2
Total liability derivatives, notional amount	689	715
Net amount on balance sheet	(4)	0
Net amount on balance sheet	49	16
Gross amount	0	0
Liability derivatives, gross asset	60	23
Asset derivatives, gross liability	(4)	0
Liability derivatives gross amount	(11)	(7)
Embedded derivative financial instruments | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, notional amount	750	750
Net amount on balance sheet	0	0
Gross amount	0	0
Asset derivatives, gross liability	0	0
Contingent consideration | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, notional amount	250	250
Net amount on balance sheet	104	65
Gross amount	104	65
Asset derivatives, gross liability	0	0
Credit default swaps – buying protection | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, notional amount	79	33
Total liability derivatives, notional amount	55	70
Net amount on balance sheet	3	(1)
Net amount on balance sheet	(1)	(4)
Gross amount	3	0
Liability derivatives, gross asset	0	0
Asset derivatives, gross liability	0	(1)
Liability derivatives gross amount	$ (1)	(4)
Credit default swaps – selling protection | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, notional amount		250
Total liability derivatives, notional amount		5
Net amount on balance sheet		6
Net amount on balance sheet		0
Gross amount		6
Liability derivatives, gross asset		0
Asset derivatives, gross liability		0
Liability derivatives gross amount		$ 0