The Company and Summary of Significant Accounting Policies - Revenue Recognition (Details)	12 Months Ended
	Dec. 31, 2016 item
Consumable virtual goods, immaterial revenue (in years)	3 years
Estimated average useful life of paying user	3 months
Number of games, longer paying user	8
Minimum
Estimated average useful life of paying user	4 months
Maximum
Estimated average useful life of paying user	7 months