Acquisitions (Details) $ in Thousands	Aug. 01, 2016 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)
Preliminary purchase price allocation
Goodwill		$ 993,633	$ 911,942
Rocket Games
Acquisitions
Percentage of outstanding equity securities acquired	100.00%
Initial cash consideration	$ 59,100
Period over which contingent consideration payments are due	2 years
Multiple applied to then-trailing 12 months of EBITDA to determine contingent consideration	6.25
Contingent purchase price consideration	$ 56,000
Preliminary purchase price allocation
Goodwill	81,700
Other intangible assets	43,400
Current assets	7,700
Other assets	300
Current contingent consideration liabilities	28,200
Other current liabilities	5,900
Non-current contingent consideration liabilities	27,800
Deferred tax liabilities	12,100
Rocket Games | Maximum
Acquisitions
Contingent purchase price consideration	$ 110,000
Rocket Games | Employee Retention Compensation
Acquisitions
Period over which contingent consideration payments are due	2 years
Rocket Games | Employee Retention Compensation | Maximum
Acquisitions
Contingent purchase price consideration	$ 10,000