Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2015
Spooky Cool Labs [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maximum amount payable	$ 58.8			$ 58.8
Contingent consideration payable	53.8			53.8
Business combination related to bonuses	5.0			5.0
Contingent consideration liability balance and bonuses settled		$ 5.0	$ 53.8
Rising Tide Games [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Maximum amount payable	140.0			140.0
Contingent consideration payable	$ 21.8			$ 21.8
Potential future payments maximum period	3 years			3 years