Acquisitions - Narrative (Details) - USD ($)				3 Months Ended
		Jan. 18, 2019	Apr. 16, 2018	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Nov. 30, 2017
Business Acquisition [Line Items]
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain				$ 2,700,000
Gain (Loss) on Sale of Investments				12,338,000
Revenue	[1]			39,472,000	$ 19,650,000
Goodwill				$ 65,368,000		$ 16,955,000
Net Income (Loss) Attributable to Noncontrolling Interest					0
Netherlands-Based Game Development Studio
Business Acquisition [Line Items]
Percentage of shares acquired			100.00%
Net purchase price			$ 4,200,000
Rhapsody America LLC
Business Acquisition [Line Items]
Percentage of shares acquired		42.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners				16.00%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Including Subsequent Acquisition, Percentage		84.00%
Business Combination, Step Acquisition, Equity Interest in Acquiree, Remeasurement Gain		$ 2,700,000
Business Combination, Step Acquisition, Initial Cash Consideration		1,000,000
Business Combination, Step Acquisition, Initial Cash Consideration, Amount Paid At Closing		200,000
Business Combination, Step Acquisition, Additional Cash Payment		14,000,000
Business Combination, Step Acquisition, Additional Cash Payment, Maximum Amount		40,000,000
Business Combination, Contingent Consideration Paid		11,600,000
Business Combination, Consideration Transferred, Settlement of Debt and Warrants		6,408,000
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value		570,000
Goodwill		48,474,000
Net purchase price		21,708,000
Rhapsody America LLC | Other Operating Income (Expense) [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred, Gain (Loss) on Settlement of Debt and Warrants		5,541,000
Business Acquisition, Release of Preexisting Foreign Currency, Adjustments		1,347,000
Rhapsody America LLC
Business Acquisition [Line Items]
Proceeds from Divestiture of Interest in Consolidated Subsidiaries		15,000,000
Maximum | Rhapsody America LLC
Business Acquisition [Line Items]
Business Combination, Step Acquisition, Additional Cash Payment		25,000,000
Minimum | Rhapsody America LLC
Business Acquisition [Line Items]
Business Combination, Step Acquisition, Additional Cash Payment		15,000,000
Minimum | Rhapsody America LLC
Business Acquisition [Line Items]
Proceeds from Divestiture of Interest in Consolidated Subsidiaries		60,000,000
Accrued Royalties, Fulfillment and Other Liabilities, Current [Member] | Rhapsody America LLC
Business Acquisition [Line Items]
Business Combination, Contingent Consideration Paid		2,600,000
Other Noncurrent Liabilities [Member] | Rhapsody America LLC
Business Acquisition [Line Items]
Business Combination, Contingent Consideration Paid		$ 9,000,000
Line of Credit [Member]
Business Acquisition [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted							$ 2,800,000
Guarantor Obligations, Maximum Exposure, Undiscounted, Gain (loss) on Elimination							$ 2,800,000
Napster [Member]
Business Acquisition [Line Items]
Revenue				$ 24,337,000	0
Goodwill				48,474,000
Napster [Member] | Operating Segments
Business Acquisition [Line Items]
Revenue				24,337,000	$ 0
Net Income (Loss) Attributable to Noncontrolling Interest				$ 1,821,000

[1] Quarters ended March 31, Components of Revenue2019 2018License Fees3,541 7,414Service Revenue35,931 12,236Net Revenue39,472 19,650 Three Months Ended March 31, Components of Revenue2019 2018License Fees$3,541 $7,414Service Revenue35,931 12,236Net Revenue$39,472 $19,650