Discontinued Operations - Additional Information (Details) - USD ($)		3 Months Ended	12 Months Ended
	Jan. 09, 2018	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Nov. 29, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Increase in fair values of Big Fish Games deferred payment and earnout liability				$ (2,300,000)
Big Fish Games | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Previously recognized compensation expense						$ 0
Compensation expense recognized due to acceleration of vesting			$ 3,400,000
Stock-based compensation expense			11,100,000	5,600,000	$ 1,300,000
Increase in fair values of Big Fish Games deferred payment and earnout liability			$ 1,100,000	$ 5,700,000	$ 21,700,000
Subsequent Event | Big Fish Games | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration in connection with the transaction	$ 990,000,000
Scenario, Forecast | Big Fish Games | Discontinued Operations, Held-for-sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Stock-based compensation expense		$ 3,500,000