Corporate Borrowings - Indebtedness Outstanding (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Feb. 14, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Credit agreement - revolver	$ 13,733		$ 1
Total indebtedness outstanding	55,909		41,508
Less unamortized loan fees	(1,401)		(448)
Total indebtedness outstanding, net	54,508		41,060
Less current maturities of long-term debt	(412)		(401)
Long-term debt and Credit Agreement - Revolver	54,096		40,659
Credit Agreement - Revolver, 1.16% (variable rate) due 2025
Debt Instrument [Line Items]
Credit agreement - revolver	$ 15,000	$ 300	0
Credit agreement, interest rate (as a percent)	1.16%
Previous Credit Agreement - Revolver, 3.19% (variable rate) due 2022
Debt Instrument [Line Items]
Credit agreement - revolver	$ 0		$ 300
Credit agreement, interest rate (as a percent)			3.19%
Secured Promissory Note, 3.71% (fixed rate) due 2022 \| Secured Debt
Debt Instrument [Line Items]
Total indebtedness outstanding	$ 909		$ 1,208
Fixed interest rate (as a percent)	3.71%
Prudential Note Purchase Agreement, 3.53% (fixed rate) due 2027 \| Secured Debt
Debt Instrument [Line Items]
Total indebtedness outstanding	$ 20,000		20,000
Fixed interest rate (as a percent)	3.53%
Prudential Note Purchase Agreement, 3.80% (fixed rate) due 2029 \| Secured Debt
Debt Instrument [Line Items]
Total indebtedness outstanding	$ 20,000		$ 20,000
Fixed interest rate (as a percent)	3.80%

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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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.

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The effective interest rate at the end of the reporting period.

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Amount of long-term debt and lease obligation, classified as noncurrent.

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Amount of long-term debt and lease obligation, classified as current.

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Amount of long-term debt and lease obligation, including portion classified as current.

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