Stock option and incentive plans (Details) (USD $)	Apr. 30, 2011	Apr. 21, 2011	Dec. 31, 2007	Jun. 30, 2007	Mar. 31, 2007	Sep. 30, 2006
Shares authorised for issuance under the Incetive plan was increased	200,000,000		100,000,000	20,000,000	15,000,000	10,000,000
Company Awarded options to purchase shares		70,000,000
Management team and Employees exercise per share		$ 0.01