Guarantee Arrangements, Pledged Assets and Repurchase Agreements - Additional Information (Detail) - USD ($) $ in Millions		1 Months Ended	12 Months Ended			36 Months Ended
		Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2007
Guarantor Obligations [Line Items]
Notional/maximum exposure to loss		$ 66,721	$ 66,721	$ 103,647
Carrying value of swap		4,135,130	4,135,130	4,212,040
Carrying value		627	627	2,621
Collateral accepted under security resale agreements, fair value		30,784	30,784	25,058
Collateral accepted under security repurchase agreements but not reported on the balance sheet that can be sold or repledged, fair value		29,835	29,835	19,558
Collateral accepted under security repurchase agreements that has been sold or repledged under repurchase agreements or to cover short sales		769	769	3,400
Net rental expense			140	143	$ 147
HSBC Securities [Member]
Guarantor Obligations [Line Items]
Whole loan securitization						$ 24,000
Securities available-for-sale [Member]
Guarantor Obligations [Line Items]
Securities pledged as collateral that can be sold or repledged by the secured party, fair value		892	892	1,000
Trading Securities [Member]
Guarantor Obligations [Line Items]
Securities pledged as collateral that can be sold or repledged by the secured party, fair value		2,772	2,772	3,797
Financial standby letters of credit, net of participations [Member]
Guarantor Obligations [Line Items]
Notional/maximum exposure to loss	[1],[2]	5,423	5,423	5,842
Carrying value	[1],[2]	0	0	0
Performance (non-financial) guarantees, net of participations [Member]
Guarantor Obligations [Line Items]
Notional/maximum exposure to loss	[1],[2]	2,969	2,969	3,008
Carrying value	[1],[2]	0	0	0
Liquidity asset purchase agreements [Member]
Guarantor Obligations [Line Items]
Notional/maximum exposure to loss	[1]	0	0	3,362
Carrying value	[1]	0	0	0
Obligation to Repurchase Receivables Sold [Member]
Guarantor Obligations [Line Items]
Outstanding repurchase demands		6	6	5	$ 3
Other liabilities [Member]
Guarantor Obligations [Line Items]
Allowance for credit losses on unfunded standby letters of credit		39	39	19
Other liabilities [Member] | Standby Letters of Credit [Member]
Guarantor Obligations [Line Items]
Deferred fees on standby letters of credit		$ 49	$ 49	$ 54
Visa Class B Shares [Member]
Guarantor Obligations [Line Items]
Shares sold (shares)		638,219
Shares held		2,300,000	2,300,000
Other Income (Loss) [Member] | Visa Class B Shares [Member]
Guarantor Obligations [Line Items]
Gain on sale of shares sold		$ 71
Swap [Member]
Guarantor Obligations [Line Items]
Carrying value of swap		$ 14	$ 14

[1] For standby letters of credit and liquidity asset purchase agreements, maximum loss represents losses to be recognized assuming the letter of credit and liquidity facilities have been fully drawn and the obligors have defaulted with zero recovery.

[2] Includes $1,315 million and $910 million issued for the benefit of HSBC affiliates at December 31, 2016 and 2015, respectively.