Securities Purchased Under Agreements to Resell and Securities Sold Under Agreements to Repurchase - Securities Sold under Agreements to Repurchase (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]
Balance at December 31	$ 567.2	$ 531.9
Average Balance During the Year	$ 433.6	$ 232.0
Average Interest Rate Paid During the Year	20.94%	0.07%
Maximum Month-End Balance During the Year	$ 869.0	$ 892.6