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Goodwill and Intangible Assets (Schedule of Goodwill) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($)
Goodwill [Roll Forward]
Balance, January 1, 2018	$ 52,990
Business acquisition	11,499
Balance, September 30, 2018	64,489
Investment Managers
Goodwill [Roll Forward]
Balance, January 1, 2018	52,990
Business acquisition	0
Balance, September 30, 2018	52,990
Investments In New Businesses
Goodwill [Roll Forward]
Balance, January 1, 2018	0
Business acquisition	11,499
Balance, September 30, 2018	$ 11,499

X

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=99380562&loc=d3e13770-109266

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X

- Definition

Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

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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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