Annual report pursuant to Section 13 and 15(d)

Fair Value Measurements and Marketable Securities - Additional Information (Detail)

v3.7.0.1
Fair Value Measurements and Marketable Securities - Additional Information (Detail) - USD ($)
shares in Millions
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Schedule Of Available For Sale Securities [Line Items]      
Recognized realized gains     $ 3,000
Recognized realized losses     0
Realized gain or losses $ 0 $ 0  
Realized gains and losses related to unrealized gains and losses in accumulated comprehensive income     $ 0
Weighted average maturity for available for sale securities 1 month 21 days    
Shares of common stock to be purchased with warrants 8.3    
Maximum      
Schedule Of Available For Sale Securities [Line Items]      
Available for sale securities, longest maturity date 2017-06