| **Discontinued Operations (Tables) - $ / shares**           | 3 Months Ended | 9 Months Ended |
|-------------------------------------------------------------|----------------|----------------|
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| **Discontinued Operations and Disposal Groups [Abstract]**  |           |           |   |   |
| Summary information of disposal classified as held for sale |           |           | The following table presents the financial results of Big Fish Games included in "(loss) income from discontinued operations, net of tax" in the accompanying condensed consolidated statements of comprehensive income:Three Months Ended September 30,Nine Months Ended September 30,(in millions)2019201820192018Net revenue$—  $—  $—  $13.2  Operating expenses—  —  —  8.4  Selling, general and administrative expense0.8  0.7  2.8  5.6  Research and development—  —  —  0.9  Total operating expense0.8  0.7  2.8  14.9  Operating loss(0.8) (0.7) (2.8) (1.7) Other income (expense)Gain on sale of Big Fish Games—  —  —  219.5  Other expense—  —  —  (0.1) Total other income —  —  —  219.4  (Loss) income from discontinued operations before provision for income taxes(0.8) (0.7) (2.8) 217.7  Income tax benefit (provision)0.4  (1.0) 0.9  (51.6) (Loss) income from discontinued operations, net of tax$(0.4) $(1.7) $(1.9) $166.1   | The Company derecognized the following upon the Big Fish Transaction:(in millions)Cash and cash equivalents$0.3  Accounts receivable34.7  Game software development, net6.7  Other current assets17.0  Property and equipment, net17.8  Game software development, net13.8  Goodwill530.7  Other intangible assets, net238.4  Other assets24.0  Accounts payable(8.5) Accrued expense(22.6) Deferred revenue(44.2) Deferred income taxes(52.0) Other liabilities(4.9) Carrying value of Big Fish Games$751.2   |
| Continuing operations (in dollars per share)                | $ 0.37         | $ 1.42         | $ 3.33 | $ 4.19 |

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No definition available.
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| - Definition
The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.
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| - Definition
Tabular disclosure of information related to a disposal group. Includes, but is not limited to, a discontinued operation, disposal classified as held-for-sale or disposed of by means other than sale or disposal of an individually significant component.
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