Acquisition (Details) - USD ($)		3 Months Ended		9 Months Ended
	Jul. 01, 2025	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Business Combination [Line Items]
Business Combination, Acquisition-Related Cost, Expense		$ 23,893,000	$ 0	$ 27,287,000	$ 0
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date		(9,020,000)		(9,020,000)
Enterprise Bancorp, Inc
Business Combination [Line Items]
Payments to Acquire Businesses, Gross	$ 25,900,000
Business Combination, Acquisition-Related Cost, Expense				27,300,000
Business Combination, Consideration Transferred, Equity Interest, Share Issued, Number of Shares	7,478,906
Business Combination, Recognized Liability Assumed, Long-Term Debt, Current	$ 62,472,000
Business Acquisition, Equity Interest Issued or Issuable Shareholders Option To Receive, Cash Per Share	$ 2.00
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares of Company Stock Issued for Each Share of Acquiree Stock	0.60
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	$ (9,000,000.0)			(9,020,000)
Business Combination, Consideration Transferred	503,100,000
Financing Receivable, Allowance for Credit Loss, Excluding Accrued Interest	$ 34,500,000
Enterprise Bancorp, Inc | Business Combination, Pro Forma Information, Nonrecurring Adjustment, Acquisition-Related Cost
Business Combination [Line Items]
Business Combination, Acquisition-Related Cost, Expense		$ 18,000,000.0		$ 38,000,000.0