Investment In Partnerships (Narrative) (Details)	9 Months Ended
Sep. 30, 2018
Soundperience GmbH [Member]
Schedule of Equity Method Investments [Line Items]
Additional percentage acquired	33.00%
Percentage ownership after transaction	49.00%
Signison [Member]
Schedule of Equity Method Investments [Line Items]
Equity method, ownership interest	50.00%

Subsidiary or Equity Method Investee, Percentage Ownership Acquired From Transaction

No definition available.

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- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571

+ Details

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- Definition

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.

+ Details

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- Definition

Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

+ References

No definition available.

+ Details

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- Details

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- Details

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