Financial Instruments - Narrative (Details) - USD ($)	3 Months Ended
Mar. 31, 2020	Jun. 30, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Cost method investments	$ 2,000,000
Non-cash impairment charge	$ 1,420,000
Available-for-sale debt securities in unrealized loss position		$ 0	$ 46,550,000
Unrealized losses		0	22,000
Accrued interest		149,000	183,000
Available-for-sale, credit loss		$ 0	$ 0

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 50
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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), in unrealized loss position without allowance for credit loss.

+ References

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Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of investment in equity security without readily determinable fair value.

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The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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