Stockholders' equity (Subsequent Events) (Details) (Subsequent Event [Member], USD $)	0 Months Ended
	Jul. 02, 2014 item
Subsequent Event [Member]
Subsequent Event [Line Items]
Options issued	75,000
Number of employees to whom options are issued	3
Average exercise price	$ 2.36
Vesting period	3 years
Expiration period	10 years