Fair Value Measurements (Reconciliation of Beginning and Ending Balances of Level 3 Measurements) (Details) - Level 3 - Convertible preferred securities - USD ($) $ in Thousands	3 Months Ended
Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2019
Reconciliation of Fair Value Measurements Using Level 3
Asset (liability), Beginning Balance	$ 8,654	$ 8,404	$ 7,404	$ 7,154
Additional investments	0	250	1,000	250
Asset (liability), Ending Balance	8,654	$ 8,654	8,404	$ 7,404
Fair Value, Recurring [Member] \| Implied based on market prices
Reconciliation of Fair Value Measurements Using Level 3
Asset fair value	$ 8,654		$ 8,404		$ 8,404

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, New Agreements

No definition available.

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- Definition

Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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- Definition

Fair value of financial instrument classified as derivative asset (liability) after deduction of derivative liability (asset), measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19279-110258

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