Loans and Allowance for Credit Losses - Loan risk ratings (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Financing receivable allowance for credit loss
Prior	$ 637,583
2019	154,380
2020	266,849
2021	539,353
2022	718,881
2023	297,855
Revolving loans	134,938
Revolving converted to term loans	3,384
Financing Receivable, before Allowance for Credit Loss, Total	2,753,223	$ 14,922
Gross charge-offs
2021	(4)
2023	(279)
Revolving converted to term loans	(1)
Total	(284)
Pass
Financing receivable allowance for credit loss
Prior	625,158
2019	154,212
2020	266,849
2021	537,489
2022	718,858
2023	297,855
Revolving loans	134,114
Revolving converted to term loans	3,085
Financing Receivable, before Allowance for Credit Loss, Total	2,737,620
Special Mention
Financing receivable allowance for credit loss
Prior	8,462
2019	142
2021	1,852
Revolving loans	635
Revolving converted to term loans	251
Financing Receivable, before Allowance for Credit Loss, Total	11,342
Substandard
Financing receivable allowance for credit loss
Prior	3,963
2019	26
2021	12
2022	23
Revolving loans	189
Revolving converted to term loans	48
Financing Receivable, before Allowance for Credit Loss, Total	4,261
Construction
Financing receivable allowance for credit loss
Prior	15,677
2019	7,228
2020	16,242
2021	42,074
2022	103,722
2023	34,080
Revolving loans	1,205
Financing Receivable, before Allowance for Credit Loss, Total	220,228
Construction | Pass
Financing receivable allowance for credit loss
Prior	15,492
2019	7,228
2020	16,242
2021	42,062
2022	103,722
2023	34,080
Revolving loans	1,205
Financing Receivable, before Allowance for Credit Loss, Total	220,031
Construction | Substandard
Financing receivable allowance for credit loss
Prior	185
2021	12
Financing Receivable, before Allowance for Credit Loss, Total	197
Residential real estate
Financing receivable allowance for credit loss
Prior	220,810
2019	35,596
2020	68,945
2021	177,830
2022	232,814
2023	127,464
Revolving loans	74,371
Revolving converted to term loans	321
Financing Receivable, before Allowance for Credit Loss, Total	938,151	8,212
Residential real estate | Pass
Financing receivable allowance for credit loss
Prior	217,796
2019	35,596
2020	68,945
2021	177,830
2022	232,814
2023	127,464
Revolving loans	73,990
Revolving converted to term loans	321
Financing Receivable, before Allowance for Credit Loss, Total	934,756
Residential real estate | Special Mention
Financing receivable allowance for credit loss
Prior	41
Revolving loans	193
Financing Receivable, before Allowance for Credit Loss, Total	234
Residential real estate | Substandard
Financing receivable allowance for credit loss
Prior	2,973
Revolving loans	188
Financing Receivable, before Allowance for Credit Loss, Total	3,161
Commercial real estate
Financing receivable allowance for credit loss
Prior	383,865
2019	106,086
2020	153,693
2021	196,734
2022	208,386
2023	71,276
Revolving loans	9,083
Revolving converted to term loans	1,223
Financing Receivable, before Allowance for Credit Loss, Total	1,130,346	1,079
Commercial real estate | Pass
Financing receivable allowance for credit loss
Prior	374,795
2019	105,944
2020	153,693
2021	195,339
2022	208,386
2023	71,276
Revolving loans	9,083
Revolving converted to term loans	1,223
Financing Receivable, before Allowance for Credit Loss, Total	1,119,739
Commercial real estate | Special Mention
Financing receivable allowance for credit loss
Prior	8,421
2019	142
2021	1,395
Financing Receivable, before Allowance for Credit Loss, Total	9,958
Commercial real estate | Substandard
Financing receivable allowance for credit loss
Prior	649
Financing Receivable, before Allowance for Credit Loss, Total	649
Commercial
Financing receivable allowance for credit loss
Prior	16,337
2019	3,927
2020	10,511
2021	34,264
2022	16,906
2023	5,100
Revolving loans	49,574
Revolving converted to term loans	1,840
Financing Receivable, before Allowance for Credit Loss, Total	138,459	15
Commercial | Pass
Financing receivable allowance for credit loss
Prior	16,181
2019	3,927
2020	10,511
2021	33,807
2022	16,906
2023	5,100
Revolving loans	49,134
Revolving converted to term loans	1,541
Financing Receivable, before Allowance for Credit Loss, Total	137,107
Commercial | Special Mention
Financing receivable allowance for credit loss
2021	457
Revolving loans	440
Revolving converted to term loans	251
Financing Receivable, before Allowance for Credit Loss, Total	1,148
Commercial | Substandard
Financing receivable allowance for credit loss
Prior	156
Revolving converted to term loans	48
Financing Receivable, before Allowance for Credit Loss, Total	204
Consumer
Financing receivable allowance for credit loss
Prior	894
2019	1,543
2020	17,458
2021	88,451
2022	157,053
2023	59,935
Revolving loans	705
Financing Receivable, before Allowance for Credit Loss, Total	326,039	$ 234
Gross charge-offs
2021	(4)
2023	(279)
Revolving converted to term loans	(1)
Total	(284)
Consumer | Pass
Financing receivable allowance for credit loss
Prior	894
2019	1,517
2020	17,458
2021	88,451
2022	157,030
2023	59,935
Revolving loans	702
Financing Receivable, before Allowance for Credit Loss, Total	325,987
Consumer | Special Mention
Financing receivable allowance for credit loss
Revolving loans	2
Financing Receivable, before Allowance for Credit Loss, Total	2
Consumer | Substandard
Financing receivable allowance for credit loss
2019	26
2022	23
Revolving loans	1
Financing Receivable, before Allowance for Credit Loss, Total	$ 50