Income Taxes - Additional Information (Detail) (USD $)
 3 Months Ended 12 Months Ended 3 Months Ended 12 Months Ended
Dec. 31, 2014
Sep. 30, 2014
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2012
Dec. 31, 2011
Income Tax [Line Items]              
U.S. federal income tax rates     34.00%        
Research and development credits available for income taxes $ 2,626,000   $ 2,626,000 $ 2,613,000      
Income tax expense (benefit)     24,277,000 1,755,000 16,566,000    
Deferred tax assets valuation allowance 44,802,000   44,802,000 23,034,000 21,600,000 21,600,000  
Change in the valuation allowance   22,300,000 21,800,000 1,400,000      
Impairment loss 0 0          
Deferred tax assets 44,802,000   44,802,000 49,392,000      
Percentage of valuation allowance 100.00%   100.00%        
Increase in income tax expense   22,300,000          
Taxable losses     10,500,000 7,600,000 3,500,000    
Income tax benefit (shortfall) of option exercises and restricted stock vesting, net     (1,200,000) (76,000.0) (4,000,000)    
Research And Development Tax Credit              
Income Tax [Line Items]              
Net operating loss carryforwards expiration year     2029        
Research and development credits available for income taxes 3,300,000   3,300,000        
Income tax expense (benefit)     547,000 398,000      
Archeo              
Income Tax [Line Items]              
Impairment loss           15,800,000  
Archeo | Discontinued Operations              
Income Tax [Line Items]              
Impairment loss           902,000  
Federal              
Income Tax [Line Items]              
Net operating loss carryforwards recorded     21,600,000        
Net operating loss carryforwards expiration year     2019        
Net operating loss carryforwards 1,700,000   1,700,000 1,700,000      
Deferred tax assets valuation allowance         16,400,000 16,400,000  
Federal | NOL carryforwards in 2012              
Income Tax [Line Items]              
Net operating loss carryforwards expiration year     2032        
Federal | Jingle Networks, Inc              
Income Tax [Line Items]              
Net operating loss carryforwards recorded             4,400,000
Net operating loss carryforwards expiration year             2026
state and city              
Income Tax [Line Items]              
Net operating loss carryforwards recorded     6,000,000        
Net operating loss carryforwards expiration year     2025        
State and Foreign Country Jurisdiction              
Income Tax [Line Items]              
Deferred tax assets valuation allowance $ 6,000,000   $ 6,000,000 $ 6,000,000      
Percentage of valuation allowance 100.00%   100.00% 100.00%