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Additional Paid-In Capital (Forfeiture rate) (Details)	3 Months Ended
	Mar. 31, 2015
Additional Paid-In Capital [Abstract]
ForfeitureRate	29.00%vgz_Forfeiturerate

X

- Details

Name:	us-gaap_AdditionalPaidInCapitalAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Average forfeiture rate for unvested share based payments

+ References

No definition available.

+ Details

Name:	vgz_Forfeiturerate
Namespace Prefix:	vgz_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration