Option agreement (Detail) (Century Thrust Joint Venture Agreement [Member], Century Concession in Laos [Member], USD $)	4 Months Ended	9 Months Ended
	Jul. 31, 2012	Jul. 31, 2012
Century Thrust Joint Venture Agreement [Member] | Century Concession in Laos [Member]
Oil and Gas Delivery Commitments and Contracts [Line Items]
Mining project, option fees paid		$ 405,000
Mining project, costs excluding option fees		20,000
Mining project, exercise price of option		1,350,000
Mining project, write-down of previously capitalized costs	$ 425,000