Bank segment - Credit risk profile - payment activity (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Credit risk profile based on payment activity for loans
Total financing receivables	$ 5,193,260	$ 5,221,204
Amortized cost> 90 days and accruing	0	0
Real estate
Credit risk profile based on payment activity for loans
Total financing receivables	4,368,723	4,313,934
Real estate | Residential 1-4 family
Credit risk profile based on payment activity for loans
Total financing receivables	2,279,671	2,299,212
Amortized cost> 90 days and accruing	0	0
Real estate | Commercial real estate
Credit risk profile based on payment activity for loans
Total financing receivables	1,115,632	1,056,982
Amortized cost> 90 days and accruing	0	0
Real estate | Home equity line of credit
Credit risk profile based on payment activity for loans
Total financing receivables	845,271	835,663
Amortized cost> 90 days and accruing	0	0
Real estate | Residential land
Credit risk profile based on payment activity for loans
Total financing receivables	22,309	19,859
Amortized cost> 90 days and accruing	0	0
Real estate | Commercial construction
Credit risk profile based on payment activity for loans
Total financing receivables	90,332	91,080
Amortized cost> 90 days and accruing	0	0
Real estate | Residential construction
Credit risk profile based on payment activity for loans
Total financing receivables	15,508	11,138
Amortized cost> 90 days and accruing	0	0
Commercial
Credit risk profile based on payment activity for loans
Total financing receivables	708,447	793,304
Amortized cost> 90 days and accruing	0	0
Consumer
Credit risk profile based on payment activity for loans
Total financing receivables	116,090	113,966
Amortized cost> 90 days and accruing	0	0
30-59 days past due
Credit risk profile based on payment activity for loans
Total financing receivables	4,267	5,703
30-59 days past due | Real estate | Residential 1-4 family
Credit risk profile based on payment activity for loans
Total financing receivables	1,920	3,019
30-59 days past due | Real estate | Commercial real estate
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
30-59 days past due | Real estate | Home equity line of credit
Credit risk profile based on payment activity for loans
Total financing receivables	969	609
30-59 days past due | Real estate | Residential land
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
30-59 days past due | Real estate | Commercial construction
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
30-59 days past due | Real estate | Residential construction
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
30-59 days past due | Commercial
Credit risk profile based on payment activity for loans
Total financing receivables	200	700
30-59 days past due | Consumer
Credit risk profile based on payment activity for loans
Total financing receivables	1,178	1,375
60-89 days past due
Credit risk profile based on payment activity for loans
Total financing receivables	3,238	2,749
60-89 days past due | Real estate | Residential 1-4 family
Credit risk profile based on payment activity for loans
Total financing receivables	2,414	1,468
60-89 days past due | Real estate | Commercial real estate
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
60-89 days past due | Real estate | Home equity line of credit
Credit risk profile based on payment activity for loans
Total financing receivables	64	86
60-89 days past due | Real estate | Residential land
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
60-89 days past due | Real estate | Commercial construction
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
60-89 days past due | Real estate | Residential construction
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
60-89 days past due | Commercial
Credit risk profile based on payment activity for loans
Total financing receivables	139	313
60-89 days past due | Consumer
Credit risk profile based on payment activity for loans
Total financing receivables	621	882
Greater than 90 days
Credit risk profile based on payment activity for loans
Total financing receivables	6,632	8,792
Greater than 90 days | Real estate | Residential 1-4 family
Credit risk profile based on payment activity for loans
Total financing receivables	4,303	6,072
Greater than 90 days | Real estate | Commercial real estate
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
Greater than 90 days | Real estate | Home equity line of credit
Credit risk profile based on payment activity for loans
Total financing receivables	1,040	1,334
Greater than 90 days | Real estate | Residential land
Credit risk profile based on payment activity for loans
Total financing receivables	397	397
Greater than 90 days | Real estate | Commercial construction
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
Greater than 90 days | Real estate | Residential construction
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
Greater than 90 days | Commercial
Credit risk profile based on payment activity for loans
Total financing receivables	40	48
Greater than 90 days | Consumer
Credit risk profile based on payment activity for loans
Total financing receivables	852	941
Total past due
Credit risk profile based on payment activity for loans
Total financing receivables	14,137	17,244
Total past due | Real estate | Residential 1-4 family
Credit risk profile based on payment activity for loans
Total financing receivables	8,637	10,559
Total past due | Real estate | Commercial real estate
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
Total past due | Real estate | Home equity line of credit
Credit risk profile based on payment activity for loans
Total financing receivables	2,073	2,029
Total past due | Real estate | Residential land
Credit risk profile based on payment activity for loans
Total financing receivables	397	397
Total past due | Real estate | Commercial construction
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
Total past due | Real estate | Residential construction
Credit risk profile based on payment activity for loans
Total financing receivables	0	0
Total past due | Commercial
Credit risk profile based on payment activity for loans
Total financing receivables	379	1,061
Total past due | Consumer
Credit risk profile based on payment activity for loans
Total financing receivables	2,651	3,198
Current
Credit risk profile based on payment activity for loans
Total financing receivables	5,179,123	5,203,960
Current | Real estate | Residential 1-4 family
Credit risk profile based on payment activity for loans
Total financing receivables	2,271,034	2,288,653
Current | Real estate | Commercial real estate
Credit risk profile based on payment activity for loans
Total financing receivables	1,115,632	1,056,982
Current | Real estate | Home equity line of credit
Credit risk profile based on payment activity for loans
Total financing receivables	843,198	833,634
Current | Real estate | Residential land
Credit risk profile based on payment activity for loans
Total financing receivables	21,912	19,462
Current | Real estate | Commercial construction
Credit risk profile based on payment activity for loans
Total financing receivables	90,332	91,080
Current | Real estate | Residential construction
Credit risk profile based on payment activity for loans
Total financing receivables	15,508	11,138
Current | Commercial
Credit risk profile based on payment activity for loans
Total financing receivables	708,068	792,243
Current | Consumer
Credit risk profile based on payment activity for loans
Total financing receivables	$ 113,439	$ 110,768