Share warrants (Details) (Warrants Issued to WestPark Capital [Member], USD $)	0 Months Ended	1 Months Ended
	Dec. 16, 2009	Sep. 19, 2008	Sep. 30, 2012
Class of Warrant or Right [Line Items]
Issuance of warrants to purchase common stock		52,500
Exercise price of warrant issued		3.9
Warrants term		5 years
Fair value of warrants		$ 276,000
Exercised shares of warrants via cashless exercise	5,000
Issuance of shares of common stock upon the exercise of warrants	2,510
Warrants to purchase shares of common stock outstanding			47,500
Minimum [Member]
Class of Warrant or Right [Line Items]
Warrants exercisable term		1 year
Maximum [Member]
Class of Warrant or Right [Line Items]
Warrants exercisable term		5 years