Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2017	Sep. 30, 2016	Mar. 31, 2016
Zindagi [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of contingent consideration liability	$ 0
Maximum amount payable			$ 60,000,000
Contingent consideration liability	200,000
Potential future payments maximum period			3 years
PuzzleSocial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of contingent consideration liability	100,000
Maximum amount payable		$ 42,000,000
Contingent consideration liability	600,000
Potential future payments maximum period		2 years 6 months
Research and Development [Member] | Zindagi and PuzzleSocial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Change in fair value of contingent consideration liability	$ 100,000