Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Loans And Leases Receivable Disclosure [Line Items]
Increase (Recaptured) in allowance for loan and lease losses	$ 4,400,000	$ 757,000,000
Commitments outstanding on troubled debt restructurings	0	0
Recorded investment in troubled debt restructurings that subsequently defaulted within twelve months	0	0
Reserve for unfunded commitments	2,000.0		$ 1,400,000
Provisions for (credits to) unfunded commitments	599,000,000	120,000,000
Charge-offs or recoveries related to reserve for unfunded commitments	0	0
Acquired Impaired Loans
Loans And Leases Receivable Disclosure [Line Items]
Increase (Recaptured) in allowance for loan and lease losses	139,000,000	2,300,000
Individually Evaluated For Impairment
Loans And Leases Receivable Disclosure [Line Items]
Increase (Recaptured) in allowance for loan and lease losses	299,000,000	2,400,000
Collectively Evaluated For Impairment
Loans And Leases Receivable Disclosure [Line Items]
Increase (Recaptured) in allowance for loan and lease losses	$ 4,900,000	$ 824,000,000