Discontinued Operations - Major Classes of Assets and Liabilities Derecognized (Details) - Discontinued Operations, Disposed of by Sale - Big Fish Games $ in Millions	Jan. 09, 2018 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash and cash equivalents	$ 0.3
Accounts receivable	34.7
Game software development, net	6.7
Other current assets	17.0
Property and equipment, net	17.8
Game software development, net	13.8
Goodwill	530.7
Other intangible assets, net	238.4
Other assets	24.0
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