Investments - Summary of Amortized Cost, Unrealized Gains and Fair Value of Short-term Investments (Detail) - USD ($) |
Jun. 30, 2015 |
Dec. 31, 2014 |
---|---|---|
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | $ 67,700,757 | $ 42,802,547 |
Unrealized Gain | 17,714 | 4,883 |
Unrealized Loss | (17,416) | (15,880) |
Fair Value | 67,701,055 | 42,791,550 |
Corporate Bonds and Notes [Member] | Short-term Investments [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 67,700,757 | 42,011,286 |
Unrealized Gain | 17,714 | 4,883 |
Unrealized Loss | (17,416) | (13,387) |
Fair Value | $ 67,701,055 | 42,002,782 |
Corporate Bonds and Notes [Member] | Long-term Investments [Member] | ||
Schedule of Available-for-sale Securities [Line Items] | ||
Amortized Cost | 791,261 | |
Unrealized Loss | (2,493) | |
Fair Value | $ 788,768 |