Short-term Investment Securities (Details) - USD ($)	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Short-term investment securities	$ 105,920,000		$ 105,920,000		$ 106,313,000
Realized gain (loss) on available-for-sale securities	0	$ 0	0	$ 0
Accumulated other comprehensive loss	894,000		894,000		532,000
Available-for-sale Securities
Debt Securities, Available-for-sale [Line Items]
Short-term investment securities	105,900,000		$ 105,900,000		106,300,000
Weighted-average fixed rate			0.30%
Unrealized loss on investment securities, net of deferred taxes	173,000	(13,000)	$ 435,000	(6,000)
Deferred taxes on unrealized (loss) gain on investment securities	51,000	$ 4,000	127,000	$ 2,000
Accumulated other comprehensive loss	$ (478,000)		$ (478,000)		$ (43,000)

Interest Income, Weighted-Average Fixed Rate

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Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), classified as current.

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Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount, before adjustment, of tax expense (benefit) for unrealized holding gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Excludes tax expense (benefit) for unrealized gain (loss) on investment in debt security measured at amortized cost (held-to-maturity) from transfer to available-for-sale.

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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.

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