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
Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018
Reconciliation of Fair Value Measurements Using Level 3
Asset (liability), Beginning Balance	$ 8,404	$ 7,404	$ 7,154	$ 7,488	$ 7,388	$ 7,388
Additional investments	0	1,000	250	986	100	0
Gains (losses) included in earnings	0			5,080
Sale proceeds	0			(6,400)
Asset (liability), Ending Balance	8,404	$ 8,404	$ 7,404	7,154	$ 7,488	$ 7,388
Implied based on market prices
Quantitative Information about Level 3 Fair Value Measurements
Asset fair value	$ 8,404			$ 7,154			$ 7,154

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

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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.

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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.

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- Definition

Amount of sales of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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

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No definition available.

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- Definition

Amount of gain (loss) recognized in income from derivative asset (liability) after deduction of derivative liability (asset), measured at fair value on recurring basis using unobservable input (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
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-Publisher FASB
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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.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19279-110258

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