Loans and Allowance for Credit Losses - Summary of the Company's Loan participations (Details) - Loan Participations and Assignments - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 1,673,339	$ 1,542,358
Non-performing Loan Rate (%)	0.00%	0.55%
Gross Charge-offs	$ 0	$ 3
Commercial and industrial | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 1,097,747	$ 1,024,131
Non-performing Loan Rate (%)	0.00%	0.83%
Gross Charge-offs	$ 0	$ 0
Commercial real estate | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 439,872	$ 422,042
Non-performing Loan Rate (%)	0.00%	0.00%
Gross Charge-offs	$ 0	$ 0
Commercial construction | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 135,612	$ 96,134
Non-performing Loan Rate (%)	0.00%	0.00%
Gross Charge-offs	$ 0	$ 0
Business banking | Commercial Portfolio Segment
Financing Receivable, Allowance for Credit Loss [Line Items]
Balance	$ 108	$ 51
Non-performing Loan Rate (%)	0.00%	0.00%
Gross Charge-offs	$ 0	$ 3