Commitments, Contingencies and Guarantees - Guarantees (Detail) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Derivatives
Guarantor Obligations [Line Items]
Carrying Value of Net Liability	$ 6,894	$ 7,485
Maximum Payout/Notional Amount by Period of Expiration	326,601	291,459
Carrying value of derivatives included derivative assets	363	578
Carrying value of derivatives included derivative liabilities	7,260	8,060
Derivatives | Year one
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	46,927	110,599
Derivatives | Years two and three
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	216,351	133,090
Derivatives | Years four and five
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	29,640	20,252
Derivatives | Years six and thereafter
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	33,683	27,518
Securities lending and clearing
Guarantor Obligations [Line Items]
Carrying Value of Net Liability	0	0
Maximum Payout/Notional Amount by Period of Expiration	28,159	20,970
Securities lending and clearing | Year one
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	28,159	20,970
Securities lending and clearing | Years two and three
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	0	0
Securities lending and clearing | Years four and five
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	0	0
Securities lending and clearing | Years six and thereafter
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	0	0
Other financial guarantees
Guarantor Obligations [Line Items]
Carrying Value of Net Liability	405	395
Maximum Payout/Notional Amount by Period of Expiration	7,411	6,872
Other financial guarantees | Year one
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	478	1,634
Other financial guarantees | Years two and three
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	3,539	3,308
Other financial guarantees | Years four and five
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	2,516	1,837
Other financial guarantees | Years six and thereafter
Guarantor Obligations [Line Items]
Maximum Payout/Notional Amount by Period of Expiration	$ 878	$ 93