Intangible and Other Assets Net - Additional Information (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Intangible Assets by Major Class [Line Items]      
Cost incurred to renew or extend term for domain names $ 2,700,000 $ 2,700,000  
Weighted average renewal period for registration fees 1 year    
Amortization expense for internet domains 239,000 336,000 520,000
Estimated amortization expense based on current amount of domains, 2015 103,000    
Estimated amortization expense based on current amount of domains, 2016 5,000    
Estimated amortization expense based on current amount of domains, thereafter $ 0