Bank segment - Credit Risk Profile - Payment Activity and Assigned Grades (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Credit risk profile by internally assigned grade for loans
Current year	$ 297,618	$ 638,750
One year before current year	586,133	1,212,344
Two years before current year	1,126,694	1,081,072
Three years before current year	996,563	747,623
Four years before current year	689,957	234,179
Prior	1,197,336	1,081,789
Revolving	1,092,901	1,145,385
Converted to term loans	77,646	69,436
Total	6,064,848	6,210,578
30-59 days past due
Credit risk profile by internally assigned grade for loans
Total	6,559	8,712
60-89 days past due
Credit risk profile by internally assigned grade for loans
Total	3,606	8,148
Greater than 89 days past due
Credit risk profile by internally assigned grade for loans
Total	18,262	23,073
Real estate | Residential 1-4 family
Credit risk profile by internally assigned grade for loans
Current year	131,347	263,605
One year before current year	253,155	411,257
Two years before current year	398,582	732,821
Three years before current year	707,065	401,163
Four years before current year	385,472	104,976
Prior	732,660	681,340
Revolving	0	0
Converted to term loans	0	0
Total	2,608,281	2,595,162
Real estate | Residential 1-4 family | Current
Credit risk profile by internally assigned grade for loans
Current year	131,347	263,605
One year before current year	253,155	407,304
Two years before current year	397,855	729,256
Three years before current year	706,189	399,766
Four years before current year	385,208	104,487
Prior	726,220	672,408
Revolving	0	0
Converted to term loans	0	0
Total	2,599,974	2,576,826
Real estate | Residential 1-4 family | 30-59 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	708
Two years before current year	0	0
Three years before current year	333	268
Four years before current year	264	0
Prior	1,541	3,525
Revolving	0	0
Converted to term loans	0	0
Total	2,138	4,501
Real estate | Residential 1-4 family | 60-89 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	726
Two years before current year	0	2,694
Three years before current year	0	0
Four years before current year	0	0
Prior	891	1,745
Revolving	0	0
Converted to term loans	0	0
Total	891	5,165
Real estate | Residential 1-4 family | Greater than 89 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	2,519
Two years before current year	727	871
Three years before current year	543	1,129
Four years before current year	0	489
Prior	4,008	3,662
Revolving	0	0
Converted to term loans	0	0
Total	5,278	8,670
Real estate | Home equity line of credit
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	891,183	957,388
Converted to term loans	68,424	59,819
Total	959,607	1,017,207
Real estate | Home equity line of credit | Current
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	888,858	954,461
Converted to term loans	67,452	59,146
Total	956,310	1,013,607
Real estate | Home equity line of credit | 30-59 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	969	1,219
Converted to term loans	419	262
Total	1,388	1,481
Real estate | Home equity line of credit | 60-89 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	624	597
Converted to term loans	449	0
Total	1,073	597
Real estate | Home equity line of credit | Greater than 89 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	732	1,111
Converted to term loans	104	411
Total	836	1,522
Real estate | Residential land
Credit risk profile by internally assigned grade for loans
Current year	5,889	3,788
One year before current year	3,689	4,772
Two years before current year	4,513	7,234
Three years before current year	3,473	1,847
Four years before current year	1,729	0
Prior	607	723
Revolving	0	0
Converted to term loans	0	0
Total	19,900	18,364
Real estate | Residential land | Current
Credit risk profile by internally assigned grade for loans
Current year	5,889	3,788
One year before current year	3,689	4,097
Two years before current year	4,513	7,234
Three years before current year	3,473	1,847
Four years before current year	1,729	0
Prior	607	723
Revolving	0	0
Converted to term loans	0	0
Total	19,900	17,689
Real estate | Residential land | 30-59 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	0	0
Real estate | Residential land | 60-89 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	675
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	0	675
Real estate | Residential land | Greater than 89 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	0	0
Real estate | Residential construction
Credit risk profile by internally assigned grade for loans
Current year	831	5,369
One year before current year	9,640	10,984
Two years before current year	6,527	1,490
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	16,998	17,843
Real estate | Residential construction | Current
Credit risk profile by internally assigned grade for loans
Current year	831	5,369
One year before current year	9,640	10,984
Two years before current year	6,527	1,490
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	16,998	17,843
Real estate | Residential construction | 30-59 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	0	0
Real estate | Residential construction | 60-89 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	0	0
Real estate | Residential construction | Greater than 89 days past due
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	0	0
Real estate | Commercial real estate
Credit risk profile by internally assigned grade for loans
Current year	35,630	104,368
One year before current year	104,725	386,119
Two years before current year	377,295	193,683
Three years before current year	191,509	267,458
Four years before current year	256,108	90,783
Prior	385,465	316,145
Revolving	15,482	15,482
Converted to term loans	0	0
Total	1,366,214	1,374,038
Real estate | Commercial real estate | Pass
Credit risk profile by internally assigned grade for loans
Current year	35,630	104,368
One year before current year	104,725	384,144
Two years before current year	376,087	180,986
Three years before current year	188,549	267,458
Four years before current year	256,108	65,625
Prior	368,171	307,367
Revolving	15,482	15,482
Converted to term loans	0	0
Total	1,344,752	1,325,430
Real estate | Commercial real estate | Special Mention
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	1,975
Two years before current year	1,208	11,159
Three years before current year	1,455	0
Four years before current year	0	14,110
Prior	1,106	3,008
Revolving	0	0
Converted to term loans	0	0
Total	3,769	30,252
Real estate | Commercial real estate | Substandard
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	1,538
Three years before current year	1,505	0
Four years before current year	0	11,048
Prior	13,990	5,770
Revolving	0	0
Converted to term loans	0	0
Total	15,495	18,356
Real estate | Commercial real estate | Doubtful
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	2,198	0
Revolving	0	0
Converted to term loans	0	0
Total	2,198	0
Real estate | Commercial real estate | 30-59 days past due
Credit risk profile by internally assigned grade for loans
Total	0	0
Real estate | Commercial real estate | 60-89 days past due
Credit risk profile by internally assigned grade for loans
Total	0	0
Real estate | Commercial real estate | Greater than 89 days past due
Credit risk profile by internally assigned grade for loans
Total	10,698	11,048
Real estate | Commercial construction
Credit risk profile by internally assigned grade for loans
Current year	0	45,863
One year before current year	68,962	33,240
Two years before current year	41,201	26,133
Three years before current year	17,685	1,333
Four years before current year	1,333	0
Prior	0	0
Revolving	79,686	65,836
Converted to term loans	0	0
Total	208,867	172,405
Real estate | Commercial construction | Pass
Credit risk profile by internally assigned grade for loans
Current year	0	45,863
One year before current year	68,962	33,240
Two years before current year	41,201	26,133
Three years before current year	17,685	1,333
Four years before current year	1,333	0
Prior	0	0
Revolving	79,686	65,836
Converted to term loans	0	0
Total	208,867	172,405
Real estate | Commercial construction | Special Mention
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	0	0
Real estate | Commercial construction | Substandard
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	0	0
Real estate | Commercial construction | Doubtful
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	0	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	0	0
Real estate | Commercial construction | 30-59 days past due
Credit risk profile by internally assigned grade for loans
Total	0	0
Real estate | Commercial construction | 60-89 days past due
Credit risk profile by internally assigned grade for loans
Total	0	0
Real estate | Commercial construction | Greater than 89 days past due
Credit risk profile by internally assigned grade for loans
Total	0	0
Consumer
Credit risk profile by internally assigned grade for loans
Current year	32,334	89,230
One year before current year	65,169	156,225
Two years before current year	123,762	10,243
Three years before current year	5,263	1,748
Four years before current year	666	530
Prior	280	200
Revolving	9,839	10,846
Converted to term loans	2,097	3,234
Total	239,410	272,256
Consumer | Current
Credit risk profile by internally assigned grade for loans
Current year	31,632	87,686
One year before current year	63,848	153,239
Two years before current year	120,783	9,852
Three years before current year	5,061	1,654
Four years before current year	648	451
Prior	280	200
Revolving	9,635	10,663
Converted to term loans	1,790	2,779
Total	233,677	266,524
Consumer | 30-59 days past due
Credit risk profile by internally assigned grade for loans
Current year	503	805
One year before current year	566	1,314
Two years before current year	1,387	176
Three years before current year	101	29
Four years before current year	4	24
Prior	0	0
Revolving	67	56
Converted to term loans	96	163
Total	2,724	2,567
Consumer | 60-89 days past due
Credit risk profile by internally assigned grade for loans
Current year	111	385
One year before current year	402	886
Two years before current year	990	114
Three years before current year	61	41
Four years before current year	8	21
Prior	0	0
Revolving	21	60
Converted to term loans	40	69
Total	1,633	1,576
Consumer | Greater than 89 days past due
Credit risk profile by internally assigned grade for loans
Current year	88	354
One year before current year	353	786
Two years before current year	602	101
Three years before current year	40	24
Four years before current year	6	34
Prior	0	0
Revolving	116	67
Converted to term loans	171	223
Total	1,376	1,589
Commercial
Credit risk profile by internally assigned grade for loans
Current year	91,587	126,527
One year before current year	80,793	209,747
Two years before current year	174,814	109,468
Three years before current year	71,568	74,074
Four years before current year	44,649	37,890
Prior	78,324	83,381
Revolving	96,711	95,833
Converted to term loans	7,125	6,383
Total	645,571	743,303
Commercial | Pass
Credit risk profile by internally assigned grade for loans
Current year	90,529	124,667
One year before current year	80,793	199,796
Two years before current year	171,002	106,669
Three years before current year	71,410	73,976
Four years before current year	44,575	37,580
Prior	75,689	80,012
Revolving	95,912	87,206
Converted to term loans	7,074	6,250
Total	636,984	716,156
Commercial | Special Mention
Credit risk profile by internally assigned grade for loans
Current year	0	1,860
One year before current year	0	6,989
Two years before current year	0	951
Three years before current year	0	0
Four years before current year	0	250
Prior	0	0
Revolving	0	7,352
Converted to term loans	0	0
Total	0	17,402
Commercial | Substandard
Credit risk profile by internally assigned grade for loans
Current year	1,058	0
One year before current year	0	2,962
Two years before current year	3,812	1,848
Three years before current year	158	98
Four years before current year	0	60
Prior	2,635	3,369
Revolving	799	1,275
Converted to term loans	51	133
Total	8,513	9,745
Commercial | Doubtful
Credit risk profile by internally assigned grade for loans
Current year	0	0
One year before current year	0	0
Two years before current year	0	0
Three years before current year	0	0
Four years before current year	74	0
Prior	0	0
Revolving	0	0
Converted to term loans	0	0
Total	74	0
Commercial | 30-59 days past due
Credit risk profile by internally assigned grade for loans
Total	309	163
Commercial | 60-89 days past due
Credit risk profile by internally assigned grade for loans
Total	9	135
Commercial | Greater than 89 days past due
Credit risk profile by internally assigned grade for loans
Total	$ 74	$ 244