Bank segment - Loan modifications (Details) - Troubled debt restructurings real estate loans $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($) contract	Mar. 31, 2020 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts \| contract	17	7
Outstanding recorded investment	$ 9,265	$ 17,488
Related allowance	$ 349	$ 4,567
Real estate \| Residential 1-4 family
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts \| contract	12	1
Outstanding recorded investment	$ 8,283	$ 148
Related allowance	$ 298	$ 8
Real estate \| Commercial real estate
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts \| contract	1	2
Outstanding recorded investment	$ 482	$ 16,584
Related allowance	$ 0	$ 4,281
Real estate \| Home equity line of credit
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts \| contract	1	0
Outstanding recorded investment	$ 170	$ 0
Related allowance	$ 21	$ 0
Real estate \| Residential land
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts \| contract	1	0
Outstanding recorded investment	$ 271	$ 0
Related allowance	$ 11	$ 0
Real estate \| Commercial construction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts \| contract	0	0
Outstanding recorded investment	$ 0	$ 0
Related allowance	$ 0	$ 0
Real estate \| Residential construction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts \| contract	0	0
Outstanding recorded investment	$ 0	$ 0
Related allowance	$ 0	$ 0
Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts \| contract	2	4
Outstanding recorded investment	$ 59	$ 756
Related allowance	$ 19	$ 278
Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of contracts \| contract	0	0
Outstanding recorded investment	$ 0	$ 0
Related allowance	$ 0	$ 0

Amount of increase (decrease) of allowance reserve for credit loss.

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

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- Definition

Amount, before troubled debt restructuring, of financing receivable to be modified.

+ References

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