Shareholders' Equity - Issued and Outstanding Preferred Stock (Parenthetical) (Detail) - $ / shares	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Class of Stock [Line Items]
Preferred stock, liquidation preference per share	$ 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, Percentage	6.45%	6.45%
Preferred Stock Dividend Rate Modifications Date Of Change	Feb. 14, 2024	Feb. 14, 2024
London Interbank Offered Rate Plus Basis Points	3.61%	3.61%
Preferred Stock, Redemption Date	Feb. 15, 2024	Feb. 15, 2024
Preferred Stock Redemption Period After Stock Disqualifies As Tier I Capital	90 days	90 days
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, Percentage	5.125%	5.125%
Preferred Stock Dividend Rate Modifications Date Of Change	Oct. 31, 2026	Oct. 31, 2026
London Interbank Offered Rate Plus Basis Points	3.52%	3.52%
Preferred Stock, Redemption Date	Nov. 01, 2026	Nov. 01, 2026
Preferred Stock Redemption Period After Stock Disqualifies As Tier I Capital	90 days	90 days
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, Percentage	5.00%	5.00%
Preferred Stock Dividend Rate Modifications Date Of Change	Jul. 31, 2024	Jul. 31, 2024
Preferred Stock, Redemption Date	Aug. 01, 2024	Aug. 01, 2024
Preferred Stock Redemption Period After Stock Disqualifies As Tier I Capital	90 days	90 days
U S Treasury Rate Plus Additional Rate	3.174%	3.174%
Preferred Stock, 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, Percentage	5.625%	5.625%
Preferred Stock Dividend Rate Modifications Date Of Change	Dec. 14, 2026	Dec. 14, 2026
Preferred Stock, Redemption Date	Apr. 01, 2027	Apr. 01, 2027
Preferred Stock Redemption Period After Stock Disqualifies As Tier I Capital	90 days	90 days
LIBOR Rate Plus Additional Rate	4.02%	4.02%
Preferred Stock, Dividend Payment Terms	three-month	three-month
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, Percentage	3.50%	3.50%
Preferred Stock Dividend Rate Modifications Date Of Change	Aug. 31, 2026	Aug. 31, 2026
Preferred Stock, Redemption Date	Sep. 01, 2026	Sep. 01, 2026
Preferred Stock Redemption Period After Stock Disqualifies As Tier I Capital	90 days	90 days
U S Treasury Rate Plus Additional Rate	2.679%	2.679%