Related Party Transactions - Narrative (Details) - USD ($)		3 Months Ended
		Jun. 30, 2023	Dec. 31, 2022
Related Party Transaction [Line Items]
Long-term debt	[1]	$ 19,671,000,000	$ 17,591,000,000
Loans receivable from related parties	[1]	57,945,000,000	59,380,000,000
Notional value of derivative contracts		1,484,673,000,000	1,327,929,000,000
Preferred stock issued		265,000,000	265,000,000
HNAH
Related Party Transaction [Line Items]
Return of capital to parent		1,000,000,000
HNAH
Related Party Transaction [Line Items]
Long-term debt		6,000,000,000	6,000,000,000
Maximum borrowing capacity		4,000,000,000
Amount outstanding under the loan agreement		0	0
Preferred stock issued		265,000,000	265,000,000
Preferred stock outstanding		265,000,000	265,000,000
HNAH | Loans And Lines Of Credit
Related Party Transaction [Line Items]
Loans receivable from related parties		1,550,000,000	1,250,000,000
HMUS | Loans And Lines Of Credit
Related Party Transaction [Line Items]
Extended loans and lines of credit		10,000,000,000	12,800,000,000
Loans receivable from related parties		1,495,000,000	2,243,000,000
Other HSBC affiliates | Loans And Lines Of Credit
Related Party Transaction [Line Items]
Extended loans and lines of credit		4,000,000,000
Loans receivable from related parties		0	0
Other HSBC affiliates | Short Term Lending
Related Party Transaction [Line Items]
Loans receivable from related parties		22,000,000	64,000,000
Related Party
Related Party Transaction [Line Items]
Long-term debt		6,010,000,000	6,011,000,000
Loans receivable from related parties		3,067,000,000	3,557,000,000
Notional value of derivative contracts		798,200,000,000	789,200,000,000
Fair value of derivative assets and liabilities		138,000,000	$ 24,000,000
Fixed Rate Note Maturing June 2025 | HNAH | Senior debt:
Related Party Transaction [Line Items]
Long-term debt		2,000,000,000
Fixed Rate Note Maturing September 2025 | HNAH | Senior debt:
Related Party Transaction [Line Items]
Long-term debt		2,000,000,000
Fixed Rate Note Maturing June 2030 | HNAH | Senior debt:
Related Party Transaction [Line Items]
Long-term debt		1,500,000,000
Fixed Rate Note Maturing December 2027 | HNAH | Senior debt:
Related Party Transaction [Line Items]
Long-term debt		$ 500,000,000

[1] The following table summarizes assets and liabilities related to our consolidated variable interest entities ("VIEs") at June 30, 2023 and December 31, 2022. Assets and liabilities exclude intercompany balances that eliminate in consolidation. See Note 17, "Variable Interest Entities," for additional information. June 30, 2023December 31, 2022(in millions)AssetsLoans, net$186 $162 Other assets40 44 Total assets$226 $206 LiabilitiesInterest, taxes and other liabilities$35 $22 Total liabilities$35 $22