Shareholders' Equity - Issued and Outstanding Preferred Stock (Parenthetical) (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Class Of Stock [Line Items]
Preferred stock, liquidation preference per share	$ 25	$ 25
Series E Fixed-To-Floating Rate Non-Cumulative Perpetual Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, liquidation preference per share	$ 1,000	$ 1,000
Preferred stock dividend rate	6.45%	6.45%
Date of change in the dividend rate	Feb. 14, 2024	Feb. 14, 2024
Secured overnight financing rate plus basis points	3.87%	3.87%
Preferred shares redemption date	Feb. 15, 2024	Feb. 15, 2024
Preferred Stock, Redemption Feature, Redemption Term	90 days	90 days
Preferred stock, dividend declared per share	$ 64.5	$ 64.5	$ 64.5
Series F Fixed-to-Floating Rate Non-Cumulative Perpetual Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, liquidation preference per share	$ 10,000	$ 10,000
Preferred stock dividend rate	5.125%	5.125%
Date of change in the dividend rate	Oct. 31, 2026	Oct. 31, 2026
Secured overnight financing rate plus basis points	3.78%	3.78%
Preferred shares redemption date	Nov. 01, 2026	Nov. 01, 2026
Preferred Stock, Redemption Feature, Redemption Term	90 days	90 days
Preferred stock, dividend declared per share	$ 512.5	$ 512.5	512.5
Series G Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, liquidation preference per share	$ 10,000	$ 10,000
Preferred stock dividend rate	5.00%	5.00%
Date of change in the dividend rate	Jul. 31, 2024	Jul. 31, 2024
Preferred shares redemption date	Aug. 01, 2024	Aug. 01, 2024
Preferred Stock, Redemption Feature, Redemption Term	90 days	90 days
Preferred stock, dividend declared per share	$ 500	$ 500	500
U S treasury rate plus additional rate	3.174%	3.174%
Dividend payment terms	five-year	five-year
Series H Fixed-to-Floating Rate Non-cumulative Perpetual Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, liquidation preference per share	$ 25	$ 25
Preferred stock dividend rate	5.625%	5.625%
Date of change in the dividend rate	Dec. 14, 2026	Dec. 14, 2026
Secured overnight financing rate plus basis points	4.28%	4.28%
Preferred shares redemption date	Apr. 01, 2027	Apr. 01, 2027
Preferred Stock, Redemption Feature, Redemption Term	90 days	90 days
Preferred stock, dividend declared per share	$ 1.4063	$ 1.0547
Series I Fixed-Rate Reset Non-Cumulative Perpetual Preferred Stock [Member]
Class Of Stock [Line Items]
Preferred stock, liquidation preference per share	$ 10,000	$ 10,000
Preferred stock dividend rate	3.50%	3.50%
Date of change in the dividend rate	Aug. 31, 2026	Aug. 31, 2026
Preferred shares redemption date	Sep. 01, 2026	Sep. 01, 2026
Preferred Stock, Redemption Feature, Redemption Term	90 days	90 days
Preferred stock, dividend declared per share	$ 350	$ 356.806	$ 94.306
U S treasury rate plus additional rate	2.679%	2.679%
Dividend payment terms	five-year	five-year