Derivatives and Hedging Activities - Credit Derivatives (Detail) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	$ 557,614	$ 510,235
Maximum Payout/Notional Amount of Purchased Credit Derivatives	619,110	569,340
Offsetting
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	444,546	418,445
Other
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	174,562	150,892
Less than 1 Year
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	138,346	132,599
1 - 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	330,401	336,151
Greater than 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	88,867	41,485
Written Credit Derivative
Derivative [Line Items]
Fair Value Asset of Written Credit Derivatives	3,918	11,182
Fair Value Liability of Written Credit Derivatives	10,192	4,663
Fair Value Net Asset/(Liability) of Written Credit Derivatives	(6,274)	6,519
0 - 250
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	446,979	461,269
0 - 250 | Offsetting
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	356,426	381,715
0 - 250 | Other
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	152,001	138,214
0 - 250 | Less than 1 Year
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	114,156	120,456
0 - 250 | 1 - 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	263,129	305,255
0 - 250 | Greater than 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	69,694	35,558
0 - 250 | Written Credit Derivative
Derivative [Line Items]
Fair Value Asset of Written Credit Derivatives	3,459	9,803
Fair Value Liability of Written Credit Derivatives	2,493	941
Fair Value Net Asset/(Liability) of Written Credit Derivatives	966	8,862
251 - 500
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	48,466	23,588
251 - 500 | Offsetting
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	42,279	17,210
251 - 500 | Other
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	7,669	7,780
251 - 500 | Less than 1 Year
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	2,562	6,173
251 - 500 | 1 - 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	33,493	14,328
251 - 500 | Greater than 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	12,411	3,087
251 - 500 | Written Credit Derivative
Derivative [Line Items]
Fair Value Asset of Written Credit Derivatives	335	924
Fair Value Liability of Written Credit Derivatives	1,813	123
Fair Value Net Asset/(Liability) of Written Credit Derivatives	(1,478)	801
501 - 1,000
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	43,352	16,939
501 - 1,000 | Offsetting
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	29,204	12,806
501 - 1,000 | Other
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	12,077	3,576
501 - 1,000 | Less than 1 Year
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	17,059	1,656
501 - 1,000 | 1 - 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	20,948	12,754
501 - 1,000 | Greater than 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	5,345	2,529
501 - 1,000 | Written Credit Derivative
Derivative [Line Items]
Fair Value Asset of Written Credit Derivatives	85	318
Fair Value Liability of Written Credit Derivatives	2,408	1,666
Fair Value Net Asset/(Liability) of Written Credit Derivatives	(2,323)	(1,348)
Greater than 1,000
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	18,817	8,439
Greater than 1,000 | Offsetting
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	16,637	6,714
Greater than 1,000 | Other
Derivative [Line Items]
Maximum Payout/Notional Amount of Purchased Credit Derivatives	2,815	1,322
Greater than 1,000 | Less than 1 Year
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	4,569	4,314
Greater than 1,000 | 1 - 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	12,831	3,814
Greater than 1,000 | Greater than 5 Years
Derivative [Line Items]
Maximum Payout/Notional Amount of Written Credit Derivatives by Tenor	1,417	311
Greater than 1,000 | Written Credit Derivative
Derivative [Line Items]
Fair Value Asset of Written Credit Derivatives	39	137
Fair Value Liability of Written Credit Derivatives	3,478	1,933
Fair Value Net Asset/(Liability) of Written Credit Derivatives	$ (3,439)	$ (1,796)