Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Significant Accounting Policies [Line Items]    
Maturity of highly liquid investments Three months or less  
Maturity of certificate More than three months  
Carrying value of cash held in money market funds $ 27,000,000  
Allowance recorded 0  
Impairment losses recognized 0  
Deferred revenue interest 0 0
Assumed expected dividend rate 0.00%  
Excess tax benefits for tax deductions 0 0
Level 2 [Member]
   
Significant Accounting Policies [Line Items]    
Assets measured using quoted prices 0  
Liabilities measured using quoted prices 0  
Level 3 [Member]
   
Significant Accounting Policies [Line Items]    
Assets measured using quoted prices 0  
Liabilities measured using quoted prices $ 0  
Minimum [Member]
   
Significant Accounting Policies [Line Items]    
Property and equipment, estimated useful life 3 years  
Maximum [Member]
   
Significant Accounting Policies [Line Items]    
Property and equipment, estimated useful life 5 years