Investment Securities - Additional Information (Details)		3 Months Ended
	Mar. 01, 2022 USD ($)	Mar. 31, 2022 USD ($) security	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Summary of Investment Holdings [Line Items]
Investment securities held to maturity		$ 2,082,242,000		$ 0
Fair value of securities transferred to held-for-maturity	$ 2,039,000,000.000
Unrealized holding loss	$ 17,000,000
Transferred from available-for-sale to held-for-maturity		(22,200,000)
Allowance for credit losses for available-for-sale debt securities		0		0
Accrued interest receivable		38,600,000		35,500,000
Allowance for securities held-to-maturity		$ 160,000
Number of securities in security portfolio | security		3,272
Number of securities in unrealized loss position | security		2,383
Total investment securities - available-for-sale		$ 8,750,604,000		7,382,066,000
Unrealized losses		467,917,000		118,235,000
Equity securities, at fair value		67,555,000		13,211,000
Gains (losses) on equity securities		(1,900,000)	$ 100,000
Impairments on equity securities without readily determinable fair value		0	$ 0
Other Assets
Summary of Investment Holdings [Line Items]
Equity securities without readily determinable fair value		240,500,000		186,000,000
Other Assets | Partnership Interest
Summary of Investment Holdings [Line Items]
Equity securities without readily determinable fair value		120,500,000
Other Assets | Initiatives in Low-to-Moderate Income Neighborhoods
Summary of Investment Holdings [Line Items]
Equity securities without readily determinable fair value		120,000,000
Pooled trust preferred securities
Summary of Investment Holdings [Line Items]
Total investment securities - available-for-sale		9,665,000		9,496,000
Unrealized losses		$ 4,097,000		$ 4,260,000