Notes Payable and advances from related parties - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Feb. 10, 2012	Jan. 17, 2012
Secured Convertible Notes Payable [Line Items]
Notes payable, refinanced with LANB principal and accrued interest				$ 708,000
Notes Payable, Total	426,000
Interest expense, Other	381,000	449,000
Notes Payable, Related Parties, Current	870,000		1,035,000
Interest Rate On Capital Lease For Equipment	7.25%
Capital Leased Assets, Gross	16,300		16,300
Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation	1,746		1,165
Equipment Under Capital Lease
Secured Convertible Notes Payable [Line Items]
Depreciation, Total	600,000
Promissory Notes
Secured Convertible Notes Payable [Line Items]
Interest expense, Other	7,000
MIT
Secured Convertible Notes Payable [Line Items]
Note payable					700,000
MIT | Promissory Notes
Secured Convertible Notes Payable [Line Items]
Monthly payment to LANB on promissory note	$ 10,000
Interest rate on promissory note	5.50%