Income taxes (Detail) (U.S. Internal Revenue Service [Member], USD $)	9 Months Ended
	Jul. 31, 2012
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	1,405,000
Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, expiration year	2029
Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards, expiration year	2030