Fair Value of Financial Instruments (Detail) - Reconciliation of all liabilities measured at fair value on a recurring basis (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Balance,Period Start Date	$ 5,967,330	$ 2,435,050
Issuances		13,693,991
Revaluation (gains) losses included in other income and expenses	(3,759,146)	(9,271,985)
Settlements		(889,726)
Balance,Period End Date	2,208,184	5,967,330
Total gains (losses) included in other income and expenses attributable to liabilities still held as of December 31	3,759,146	9,326,210
Warrant Derivatives [Member]
Balance,Period Start Date	655,219	2,240,962
Revaluation (gains) losses included in other income and expenses	(552,524)	(1,269,940)
Settlements		(315,803)
Balance,Period End Date	102,695	655,219
Total gains (losses) included in other income and expenses attributable to liabilities still held as of December 31	552,524	1,324,165
Conversion Element OF Promissory Notes [Member]
Balance,Period Start Date	1,931,295
Issuances		11,495,163
Revaluation (gains) losses included in other income and expenses	(1,656,367)	(8,989,945)
Settlements		(573,923)
Balance,Period End Date	274,928	1,931,295
Total gains (losses) included in other income and expenses attributable to liabilities still held as of December 31	1,656,367	8,989,945
Conversion Elements Of Series B Convertible Preference Share [Member]
Balance,Period Start Date	1,245,101	194,088
Revaluation (gains) losses included in other income and expenses	(34,192)	1,051,013
Balance,Period End Date	1,210,909	1,245,101
Total gains (losses) included in other income and expenses attributable to liabilities still held as of December 31	34,192	(1,051,013)
Series A Convertible Preference Share Derivatives [Member]
Balance,Period Start Date	2,135,715
Issuances		2,198,828
Revaluation (gains) losses included in other income and expenses	(1,516,063)	(63,113)
Balance,Period End Date	619,652	2,135,715
Total gains (losses) included in other income and expenses attributable to liabilities still held as of December 31	$ 1,516,063	$ 63,113