Pledged and Restricted Assets - Narrative (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Financial Instruments Owned and Pledged as Collateral [Line Items]
Cash, held in foreign currency	$ 330,400,000
Restricted cash	574,200,000	$ 641,600,000
Average deposits maintained to meet Federal Reserve Bank reserve requirements	0	0
Collateral that may be repledged or sold
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged assets	43,200,000,000	54,600,000,000
Asset Pledged as Collateral with Right
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged assets	464,700,000	524,100,000
Collateral Requirements | Collateral that may be repledged or sold
Financial Instruments Owned and Pledged as Collateral [Line Items]
Pledged assets	$ 8,700,000,000	$ 5,600,000,000