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Borrowings (Narrative) (Details) - USD ($) |  |  | 12 Months Ended |
--- | --- | --- | --- | ---
Oct. 07, 2021 | Apr. 15, 2015 | Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020 | Oct. 07, 2020
Short Term And Long Term Borrowings [Line Items] |  |  |  |  |  |
Short-term FHLB borrowings |  |  | $ 205,000,000 | $ 30,000,000 |  |
Short-term borrowings, weighted average rate |  |  | 4.60% | 0.34% |  |
Line of credit drawn amount |  |  | $ 0 | $ 0 |  |
Debt issuance costs |  |  | $ (0) | (0) | $ 779,000 |
2020 Notes [Member] |  |  |  |  |  |
Short Term And Long Term Borrowings [Line Items] |  |  |  |  |  |
Debt issuance cost amortization date |  |  | Oct. 15, 2025 |  |  |
2020 Notes [Member] | Private Placement [Member] |  |  |  |  |  |
Short Term And Long Term Borrowings [Line Items] |  |  |  |  |  |
Debt instrument, aggregate principal amount |  |  |  |  |  | $ 35,000,000.0
Debt instrument, maturity date | Oct. 15, 2030 |  |  |  |  |
Debt instrument, payment terms |  |  | The 2020 Notes have a maturity date of October 15, 2030 and bear interest, payable semi-annually, at the rate of 4.375% per annum, until October 15, 2025. Commencing on that date, the interest rate will reset quarterly to an interest rate per annum equal to the then current three-month secured overnight financing rate (“SOFR”) plus 4.265%, payable quarterly until maturity. |  |  |
Debt instrument, interest rate | 4.375% |  |  |  |  |
Debt issuance costs | $ 779,000 |  |  |  |  |
Proceeds from issuance of debt, net | $ 34,200,000 |  |  |  |  |
2020 Notes [Member] | Private Placement [Member] | Secured Overnight Financing Rate (“SOFR”) [Member] |  |  |  |  |  |
Short Term And Long Term Borrowings [Line Items] |  |  |  |  |  |
Debt instrument, percentage of basis spread on variable rate | 4.265% |  |  |  |  |
2015 Notes [Member] |  |  |  |  |  |
Short Term And Long Term Borrowings [Line Items] |  |  |  |  |  |
Debt instrument, aggregate principal amount |  | $ 40,000,000.0 |  |  |  |
Debt instrument, interest rate |  | 6.00% |  |  |  |
Debt issuance costs |  |  | $ 1,100,000 |  |  |
Proceeds from issuance of debt, net |  |  | $ 38,900,000 |  |  |
Number of years at stated rate |  |  | 10 years |  |  |
Debt issuance cost amortization date |  |  | Apr. 15, 2025 |  |  |
2015 Notes [Member] | LIBOR [Member] |  |  |  |  |  |
Short Term And Long Term Borrowings [Line Items] |  |  |  |  |  |
Debt instrument, percentage of basis spread on variable rate |  | 3.944% |  |  |  |
Commercial Bank [Member] |  |  |  |  |  |
Short Term And Long Term Borrowings [Line Items] |  |  |  |  |  |
Revolving line of credit allowing borrowings |  |  | $ 20,000,000.0 |  |  |
Federal Home Loan Borrowings Short Term Advances [Member] |  |  |  |  |  |
Short Term And Long Term Borrowings [Line Items] |  |  |  |  |  |
Short-term FHLB borrowings |  |  | $ 205,000,000.0 | $ 30,000,000.0 |  |

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- Definition Amount of advance from Federal Home Loan Bank (FHLBank) maturing in next fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=6479118&loc=d3e64650-112822 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=123465755&loc=d3e1835-112601 + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910 + Details
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