Segment Reporting - Reconciliation of Segment Earnings to Earnings Before Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating earnings (losses)	$ 16,159	$ (5,747)	$ 7,800
General and administrative	(13,701)	(10,284)	(10,198)
Gain on dissolution of investment	0	0	573
Interest income	243	656	2,766
Interest expense	(746)	(444)	(636)
Earnings (Losses) before income taxes	15,656	(5,535)	10,503
Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating earnings (losses)	29,860	4,537	17,998
Other
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Operating earnings (losses)	0	0	0
Segment Reconciling Items
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Gain on dissolution of investment	0	0	573
Interest income	243	656	2,766
Interest expense	$ (746)	$ (444)	$ (636)

Amount of gain (loss) from sale and disposal of integrated set of activities and assets capable of being conducted and managed for purpose of providing return in form of dividend, lower cost, or other economic benefit to investor, owner, member and participant.

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The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

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