Loans and the Allowance for Loan Losses - Past Due Loans Receivable (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	$ 5,220,118,000	$ 4,992,785,000
Recorded Investment Over 90 Days Past Due and Still Accruing	185,000	127,000
30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	18,576,000	3,692,000
60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	1,886,000	3,386,000
Greater Than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	22,653,000	12,020,000
Total Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	43,115,000	19,098,000
Current
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	5,177,003,000	4,973,687,000
Real Estate Loans:
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	3,654,601,000	3,570,120,000
Recorded Investment Over 90 Days Past Due and Still Accruing	56,000	64,000
Real Estate Loans: | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	12,060,000	2,311,000
Real Estate Loans: | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	1,323,000	3,063,000
Real Estate Loans: | Greater Than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	16,787,000	10,210,000
Real Estate Loans: | Total Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	30,170,000	15,584,000
Real Estate Loans: | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	3,624,431,000	3,554,536,000
Real Estate Loans: | Commercial
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	2,256,370,000	2,217,928,000
Recorded Investment Over 90 Days Past Due and Still Accruing	0	44,000
Real Estate Loans: | Commercial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	3,745,000	240,000
Real Estate Loans: | Commercial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	77,000	536,000
Real Estate Loans: | Commercial | Greater Than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	6,751,000	2,954,000
Real Estate Loans: | Commercial | Total Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	10,573,000	3,730,000
Real Estate Loans: | Commercial | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	2,245,797,000	2,214,198,000
Real Estate Loans: | Construction
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	654,353,000	669,798,000
Recorded Investment Over 90 Days Past Due and Still Accruing	56,000	0
Real Estate Loans: | Construction | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	7,511,000	279,000
Real Estate Loans: | Construction | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	0	1,320,000
Real Estate Loans: | Construction | Greater Than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	5,171,000	3,198,000
Real Estate Loans: | Construction | Total Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	12,682,000	4,797,000
Real Estate Loans: | Construction | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	641,671,000	665,001,000
Real Estate Loans: | Residential
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	743,878,000	682,394,000
Recorded Investment Over 90 Days Past Due and Still Accruing	0	20,000
Real Estate Loans: | Residential | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	804,000	1,792,000
Real Estate Loans: | Residential | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	1,246,000	1,207,000
Real Estate Loans: | Residential | Greater Than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	4,865,000	4,058,000
Real Estate Loans: | Residential | Total Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	6,915,000	7,057,000
Real Estate Loans: | Residential | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	736,963,000	675,337,000
Commercial
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	1,496,480,000	1,358,838,000
Recorded Investment Over 90 Days Past Due and Still Accruing	103,000	52,000
Commercial | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	6,365,000	1,101,000
Commercial | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	522,000	71,000
Commercial | Greater Than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	5,346,000	1,622,000
Commercial | Total Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	12,233,000	2,794,000
Commercial | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	1,484,247,000	1,356,044,000
Consumer and Other
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	69,037,000	63,827,000
Recorded Investment Over 90 Days Past Due and Still Accruing	26,000	11,000
Consumer and Other | 30-59 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	151,000	280,000
Consumer and Other | 60-89 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	41,000	252,000
Consumer and Other | Greater Than 90 Days Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	520,000	188,000
Consumer and Other | Total Past Due
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	712,000	720,000
Consumer and Other | Current
Financing Receivable, Past Due [Line Items]
Financing receivable, excluding accrued interest, before allowance for credit loss	$ 68,325,000	$ 63,107,000