Fair Value of Financial Instruments -Summary of Changes in Accrued License Fees and Debt Conversion Feature Liability Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Detail) (Level 3 [Member], USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Ending balance		$ 81,904
Accrued License Fees [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Ending balance	24,826,374
Debt Conversion Feature Liability [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Ending balance	1,531,867
Fair Value, Measurements, Recurring [Member] | Accrued License Fees [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	19,865,863
Additions	0	0
Adjustments Resulting from Changes In Fair Value Recognized in Earnings	4,960,511
Ending balance	24,826,374
Fair Value, Measurements, Recurring [Member] | Debt Conversion Feature Liability [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	1,449,211	71,655
Additions	0	0
Adjustments Resulting from Changes In Fair Value Recognized in Earnings	82,656	10,249
Ending balance	$ 1,531,867	$ 81,904