Fair Value Disclosures (Quantitative Information About Level 3 Fair Value Measurements) (Details) - Significant Unobservable Inputs (Level 3) [Member] - USD ($)	Sep. 30, 2018	Dec. 31, 2017
CLOs [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value	$ 3,135,000	$ 4,485,000
Measurement Input		2.0
CLOs [Member] \| Yield [Member] \| Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Input	9.7	11.8
CLOs [Member] \| Yield [Member] \| Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Input	12.2	19.1
CLOs [Member] \| Yield [Member] \| Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Input	11.1	13.8
CLOs [Member] \| Duration [Member] \| Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Term	6 years 9 months 18 days	4 years 3 months 18 days
CLOs [Member] \| Duration [Member] \| Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Term	8 years	4 years 6 months
CLOs [Member] \| Duration [Member] \| Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Term	7 years 3 months 18 days	4 years 4 months 24 days
CLOs [Member] \| Default Rate [Member] \| Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Input	2
CLOs [Member] \| Default Rate [Member] \| Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Input	2
CLOs [Member] \| Default Rate [Member] \| Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Input	2.0	2.0
Equity securities [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value		$ 2,066,000
Equity securities [Member] \| EBITDA Multiple [Member] \| Minimum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Input		7.6
Equity securities [Member] \| EBITDA Multiple [Member] \| Maximum [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Input		9.2
Equity securities [Member] \| EBITDA Multiple [Member] \| Weighted Average [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Measurement Input		8.00

Amount of 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 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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Value of input used to measure investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ 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 (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=99377092&loc=SL75136599-209740

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- Definition

Value of input used to measure investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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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.

+ References

No definition available.

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