Loans, Allowance for Credit Losses and Credit Quality - Textual (Details) - USD ($) $ in Thousands		9 Months Ended
		Sep. 30, 2025		Jun. 30, 2025	Dec. 31, 2024	Sep. 30, 2024		Jun. 30, 2024	Dec. 31, 2023
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses		$ 190,476	[1]	$ 144,773	$ 169,984	$ 163,696	[1]	$ 150,859	$ 142,222
Unfunded commitments		$ 1,700
Days to be termed as non accrual loans		90 days
Financing Receivable, Nonaccrual	[2]	$ 86,597			101,529
Financing receivable, net deferred costs		7,200			6,100
Financing Receivable, Unamortized Loan Cost (Fee) and Purchase Premium (Discount)		163,100			8,100
Additional commitments to lend to borrowers experiencing financial difficulty party to a loan modification		2,500				0
Financing Receivable, Allowance for Credit Loss, Period Increase (Decrease)		(20,500)
Commercial And Industrial [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses		54,482	[1]	38,451	30,799	32,205	[1]	38,393	36,049
Financing Receivable, Nonaccrual		23,173			14,454
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses		77,083	[1]	$ 60,927	93,718	$ 87,459	[1]	$ 67,051	$ 61,305
Financing Receivable, Nonaccrual		$ 29,216			$ 74,343

[1] Balances of accrued interest receivable excluded from amortized cost and the calculation of allowance for credit losses amounted to $70.8 million and $55.3 million as of September 30, 2025 and September 30, 2024, respectively.

[2] (1)Non-accrual balances reported above without an allowance for credit losses are attributable to loans evaluated on an individual basis where it was determined that there was no risk of loss due to sufficient underlying collateral values.