Fair Value Measurements (Financial Assets Measured at Fair Value on a Recurring Basis) (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	$ 24,420	$ 22,179
Amortized Cost	24,420	22,179
Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	19,046	16,805
Amortized Cost	19,046	16,805
Cash and Cash Equivalents \| Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	18,460	14,887
Amortized Cost	18,460	14,887
Cash and Cash Equivalents \| Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	586	1,918
Amortized Cost	586	1,918
Restricted cash equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	5,374	5,374
Amortized Cost	5,374	5,374
Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	22,546	20,305
Level 1 \| Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	19,046	16,805
Level 1 \| Cash and Cash Equivalents \| Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	18,460	14,887
Level 1 \| Cash and Cash Equivalents \| Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	586	1,918
Level 1 \| Restricted cash equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	3,500	3,500
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	1,874	1,874
Level 2 \| Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 2 \| Cash and Cash Equivalents \| Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 2 \| Cash and Cash Equivalents \| Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 2 \| Restricted cash equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	1,874	1,874
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 3 \| Cash and Cash Equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 3 \| Cash and Cash Equivalents \| Cash
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 3 \| Cash and Cash Equivalents \| Money market funds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Level 3 \| Restricted cash equivalents
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financial assets fair value	0	0
Napster
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued royalties, fulfillment and other current liabilities, Napster acquisition contingent consideration	5,396	2,800
Other long-term liabilities, Napster acquisition contingent consideration	6,904	9,800
Total liabilities	12,300	12,600
Napster \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued royalties, fulfillment and other current liabilities, Napster acquisition contingent consideration	0	0
Other long-term liabilities, Napster acquisition contingent consideration	0	0
Total liabilities	0	0
Napster \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued royalties, fulfillment and other current liabilities, Napster acquisition contingent consideration	0	0
Other long-term liabilities, Napster acquisition contingent consideration	0	0
Total liabilities	0	0
Napster \| Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued royalties, fulfillment and other current liabilities, Napster acquisition contingent consideration	5,396	2,800
Other long-term liabilities, Napster acquisition contingent consideration	6,904	9,800
Total liabilities	$ 12,300	$ 12,600

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ 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)
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Amount of liability recognized arising from contingent consideration in a business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476

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