Fair Value Measurement - Roll Forward for Financial Assets and Liabilities Measured at Fair Value Using Significant Other Observable Inputs (Level 2) (Detail) (Fair Value, Measurements [Member], USD $)	6 Months Ended
	Jun. 30, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable debt securities, Ending Balance	$ 17,334,018
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable debt securities, Ending Balance
Significant Other Observable Inputs (Level 2) [Member] | Bonds payable [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Marketable debt securities, Beginning Balance	125,000
Financial liabilities change settled in earning fair value disclosure	(107,083)
Marketable debt securities, Ending Balance	$ 17,917